# Mast Myths?



## sstv (Jul 30, 2006)

Hi All
We have all read about how the dish mast must be plumb and no matter what happens after a installation, a plumb mast is a must.
I don't think this is true. A plumb mast and using the coordinates will get you into the ball park quickly after that its a matter of tweaking Tilt, Elevation and Azimuth.
This tweaking can be done even if the mast is not plumb it just takes a little longer and the results are the same. 
I don't think you find any istaller reinstalling a pole mount dish because the pole was not plumb.

SSTV
since 94


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## veryoldschool (Dec 10, 2006)

sstv said:


> Hi All
> We have all read about how the dish mast must be plumb and no matter what happens after a installation, a plumb mast is a must.
> I don't think this is true. A plumb mast and using the coordinates will get you into the ball park quickly after that its a matter of tweaking Tilt, Elevation and Azimuth.
> This tweaking can be done even if the mast is not plumb it just takes a little longer and the results are the same.
> ...


I've stated the same thing for some time, "but" this seems to be only true with the circular polarization SATs. If you're trying to do this with a linear polarization SAT, you may find this much harder.


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## gfrang (Aug 30, 2007)

The only problem with a mast that is unplumbed is like if you move the az the el will change.


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## joe diamond (Feb 28, 2007)

Of course you can hit a signal with an out of column mast. It is just harder. So the wise tech checks for plumb first. If the dish is out you look for a reason like loose bolts. Then you straighten the mast and sometimes a perfect signal arrives. 

Sometimes you have to screw around a little and run the signal meter for the customer. It softens the blow that they are paying for a service call because the mast bolts were loose.

It is a left / right & up / down thing.

Joe


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## BattleZone (Nov 13, 2007)

As the others have stated, it IS of course _possible_ to peak a dish without a plumb mast, but because a non-plumb mast means you are moving the dish in two dimensions at a time instead of one, it can be considerably more difficult to tune in the dish. Difficult enough that an experienced tech with a good meter can have trouble, so advising a normal customer, with little experience and probably using the "cell phone relay from the receiver's meter" method, to accept a non-plumb mast doesn't make a lot of sense.


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## veryoldschool (Dec 10, 2006)

BattleZone said:


> As the others have stated, it IS of course _possible_ to peak a dish without a plumb mast, but because a non-plumb mast means you are moving the dish in two dimensions at a time instead of one, it can be considerably more difficult to tune in the dish. Difficult enough that an experienced tech with a good meter can have trouble, so advising a normal customer, with little experience and probably using the "cell phone relay from the receiver's meter" method, to accept a non-plumb mast doesn't make a lot of sense.


You make a good point. If one doesn't understand how the three adjustments interact, then it could be troublesome. "On the other hand" if one does, then I wouldn't think it would add more than 10-15 mins to the job.
For all installers, this would be simply taking money out of their paycheck though.


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## sstv (Jul 30, 2006)

Hi All
My post was aimed at the person that had a working system and started to get the "looking for Sat" screen.
Probably a small tweak will get everything working OK with no need to worry about a plumb mast.
If the original set up was with a non plumb mast, plumbing up the mast will really mess things up.

SSTV 
since 94


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## Doug Brott (Jul 12, 2006)

Folks, I did a little cleanup in this thread .. Please try to stay on topic.


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## gfrang (Aug 30, 2007)

sstv said:


> Hi All
> My post was aimed at the person that had a working system and started to get the "looking for Sat" screen.
> Probably a small tweak will get everything working OK with no need to worry about a plumb mast.
> If the original set up was with a non plumb mast, plumbing up the mast will really mess things up.
> ...


Ok i have a pole that isn't perfectly plum so i start with the asmurith first and then do the elevation last.This gives me the best peak.


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## veryoldschool (Dec 10, 2006)

gfrang said:


> Ok i have a pole that isn't perfectly plum so i start with the asmurith first and then do the elevation last.This gives me the best peek.


So what do you see when you "peek", that's it's "peaked"?
[sorry I couldn't resist]. :lol:


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## gfrang (Aug 30, 2007)

veryoldschool said:


> So what do you see when you "peek", that's it's "peaked"?
> [sorry I couldn't resist]. :lol:


Fixed it at least i think i did.

Oh yea just remembered something the 3 rules in dish pointing dither,dither and dither.


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## ndole (Aug 26, 2009)

I've been guilty once or twice of dropping the mast and compensating the settings in order to squeeze around a stray branch. It's not the way to go if you can avoid it. Set the mast correctly!


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## texasbrit (Aug 9, 2006)

If you don't get the mast plumb it can make it much more difficult to peak the signals because as has been posted changes in one parameter affect both the others. I am a firm believer in spending as much time as necessary in getting the mast plumb. If you do this then even a coarse alignment can give you nearly perfect signals. I installed two SL5 SWMs this weekend, no meter, just the receiver and a small TV. Basic install of the mast including monopoles, 35 minutes each. Getting it plumb, five to seven minutes each. Peaking the dish, three minutes on one dish and two minutes on the other. 101/119 signals mostly 100. 99c and 103c signals in the mid-90s.


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## cartrivision (Jul 25, 2007)

gfrang said:


> The only problem with a mast that is unplumbed is like if you move the az the el will change.


The only way that would be a "problem" is if you somehow knew that the elevation setting was _exactly_ correct and that only the azimuth was off.... but that is never the case, and it doesn't matter anyway because it's all relative. Just because changing the azimuth setting on a off-plumb mount also changes the *true* elevation of the dish, if the relative (off-plumb) elevation setting is already at the optimal setting, changing the azimuth setting will not make any further adjustment of the elevation setting necessary.

It's like aiming a crosshair gun sight. The orientation of the sight/gun is irrelevant. *If the horizontal crosshair line is exactly on the target,* (but for example that "horizontal" crosshair line is really 30 degrees off of true horizontal) to get exactly on target, you have to then move the gun in the direction of the line of the cross-hair that is already on the target, even though that will be moving the gun's _true_ orientation in both the vertical and horizontal direction, it's still only moving the relative orientation (as observed through the crosshair sight) on a single (relative) axis.


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> The only way that would be a "problem" is if you somehow knew that the elevation setting was _exactly_ correct and that only the azimuth was off.... but that is never the case, and it doesn't matter anyway because it's all relative. Just because changing the azimuth setting on a off-plumb mount also changes the *true* elevation of the dish, if the relative (off-plumb) elevation setting is already at the optimal setting, changing the azimuth setting will not make any further adjustment of the elevation setting necessary.
> 
> It's like aiming a crosshair gun sight. The orientation of the sight/gun is irrelevant. *If the horizontal crosshair line is exactly on the target,* (but for example that "horizontal" crosshair line is really 30 degrees off of true horizontal) to get exactly on target, you have to then move the gun in the direction of the line of the cross-hair that is already on the target, even though that will be moving the gun's _true_ orientation in both the vertical and horizontal direction, it's still only moving the relative orientation (as observed through the crosshair sight) on a single (relative) axis.


The is it's much easier to peak the dish if adjustments made only happen in one plane. This is especially true if you're a novice installing your own dish.

Of course I have no idea how much variability you have in elevation (how tight the tolerances are) but there's no doubt that if the mast is out of plumb it adds a complication to peaking the dish.

Mike


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## cartrivision (Jul 25, 2007)

BattleZone said:


> As the others have stated, it IS of course _possible_ to peak a dish without a plumb mast, but because a non-plumb mast means you are moving the dish in two dimensions at a time instead of one, it can be considerably more difficult to tune in the dish. Difficult enough that an experienced tech with a good meter can have trouble, so advising a normal customer, with little experience and probably using the "cell phone relay from the receiver's meter" method, to accept a non-plumb mast doesn't make a lot of sense.


This is logically incorrect. As I explained in my previous post, it's all relative, so the fact that you are moving in two "true" dimensions is meaningless and adds absolutely no complexity to doing the fine tuning (peaking) adjustments, because the az or el adjustments on an off plumb mount will still only move the dish on a single axis. The fact that that axis does not match true horizontal and vertical is completely irrelevant when fine tuning the az & el settings on the mount. Once either one is set at the optimal setting, changing the other one will not move the first off of that optimal setting or cause the first one to have to be adjusted again.

The only thing that an off plumb mast does is make the elevation markings on the mount incorrect, which will possibly make it much harder to do the rough aiming to just find any signal from the 101 sat, since you might have to rough aim in both the vertical and horizontal directions to find the correct rough aim that gives you some signal from the 101 sat.... but once that rough aim is done and you have some signal from the 101 sat, an out of plumb mast will change nothing whatsoever in the "peaking" procedure from that point on.


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> The is it's much easier to peak the dish if adjustments made only happen in one plane. This is especially true if you're a novice installing your own dish.
> 
> Of course I have no idea how much variability you have in elevation (how tight the tolerances are) but there's no doubt that if the mast is out of plumb it adds a complication to peaking the dish.
> 
> Mike


It makes absolutely no difference whatsoever. If the mast is out of plumb, the adjustments still happen in only one plane at a time.

The fact that those two perpendicular planes that are defined by the out of plumb mast are oriented in a different direction than two other planes in space that happen to be defined by the earth's horizon and a plane perpendicular to that, doesn't change the fact that turning either the az or el adjustment bolts will still only move the dish along one single plane for the az bolt and along one single plane for the el bolt.

There is nothing magical about the plane that is defined by the earth's horizon from some position on earth. The satellite position is always stationary relative to the location of the dish, and any arbitrary orientation of the dish mount can be chosen and called plumb from an arbitrary "horizontal" plane, and the fine adjustments will still only move the dish along one plane each for what you have arbitrarily decided to define as the horizontal and vertical planes.

*To make it even more crystal clear that the orientation of the mast does not change how the az and el fine tuning adjustments do or don't interact with each other.... consider the fact that since the earth is a sphere, every single "plumb mast" that a dish is mounted on is pointing in a different direction. That's right. No plumb mast anywhere on earth is parallel to any other plumb mast in any other location on earth, so either only one of them can possibly be pointing in the "right direction" or the direction that the mast points must be irrelevant to the az/el fine tuning process.*


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> It makes absolutely no difference whatsoever. If the mast is out of plumb, the adjustments still happen in only one plane at a time.
> 
> The fact that those two perpendicular planes that are defined by the out of plumb mast are oriented in a different direction than two other planes in space that happen to be defined by the earth's horizon and a plane perpendicular to that, doesn't change the fact that turning either the az or el adjustment bolts will still only move the dish along one single plane for the az bolt and along one single plane for the el bolt.
> 
> ...


So you're saying that if a mast is not plumb and I rotate the dish about the mast that the elevation of that dish does not change relative to the plane tangent to the horizon? Is that what you're trying say?

BTW, the fact that the earth is round and plumb is relative to given area is why there are different dish position settings based on area.

Mike


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## RobertE (Jun 10, 2006)

cartrivision said:


> It makes absolutely no difference whatsoever. If the mast is out of plumb, the adjustments still happen in only one plane at a time.
> 
> The fact that those two perpendicular planes that are defined by the out of plumb mast are oriented in a different direction than two other planes in space that happen to be defined by the earth's horizon and a plane perpendicular to that, doesn't change the fact that turning either the az or el adjustment bolts will still only move the dish along one single plane for the az bolt and along one single plane for the el bolt.
> 
> ...


What your saying is absolutely true in regards to a single sat dish (circular polarity not linear). The relative axis for AZ/EL vs the true axis really makes no difference. You can have the dish mounted all sorts of funky ways and still be able to get a good signal.

Things get real complicated when dealing with a multisat dish such as the slimline. When doing the fine adjustments to say the AZ, your also changing the EL, while it won't affect the 101 a whole lot, it can have pretty dramatic results on the 119. Same for EL affecting the AZ.

Can it be done? Sure. Is it as simple as you make it out to be? Absolutely not.


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## texasbrit (Aug 9, 2006)

RobertE said:


> What your saying is absolutely true in regards to a single sat dish (circular polarity not linear). The relative axis for AZ/EL vs the true axis really makes no difference. You can have the dish mounted all sorts of funky ways and still be able to get a good signal.
> 
> Things get real complicated when dealing with a multisat dish such as the slimline. When doing the fine adjustments to say the AZ, your also changing the EL, while it won't affect the 101 a whole lot, it can have pretty dramatic results on the 119. Same for EL affecting the AZ.
> 
> Can it be done? Sure. Is it as simple as you make it out to be? Absolutely not.


Absolutely agree. With a multisat dish the required azimuth, elevation and tilt for a given location are based on the mount being absolutely perpendicular to the earth's surface at that point. If the mount is perpendicular (plumb) then making adjustments to the elevation (say) does not change the pointing azimuth of the dish. If the mount is not perpendicular, then if you get the correct azimuth setting and then change the elevation, the pointed azimuth of the dish will shift. You can still get the dish pointed correctly, it's just that it will take longer and involve multiple corrections. The nice thing about getting the dish absolutely plumb is that unless the dish surface itself or the LNB mountings are screwed up, you should not need to adjust either the elevation or tilt setting on the dish to get a peak signal. If there were a way of setting the dish azimuth visually to the correct value you would not need to adjust the azimuth either! 
Let's put it another way. A correctly manufactured dish with a perfectly plumb mount, preset accurately to the correct tilt and elevation, and set exactly to the correct azimuth, for the location, should not need any adjustment at all. No dithering, nothing. No magic, just geometry. The only reason we have to go through the dithering process at all is because we can only set up the azimuth approximately using a compass, or because the dish mount is not plumb, or because we don't preset the elevation/tilt accurately enough.


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## veryoldschool (Dec 10, 2006)

texasbrit said:


> The only reason we have to go through the dithering process at all is because we can only set up the azimuth approximately using a compass, or because the dish mount is not plumb, or because we don't preset the elevation/tilt accurately enough.


Not to disagree, but I do it to make sure [verify] I'm centered on the SATs.


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## texasbrit (Aug 9, 2006)

veryoldschool said:


> Not to disagree, but I do it to make sure [verify] I'm centered on the SATs.


You're not disagreeing - I am just pointing out that if it were possible to set the dish to the exact azimuth you needed (very precisely) then you would not need to dither in azimuth either. There's no way to set the dish precisely in azimuth which is why you have to dither to find the center of the 101 beam. 
If the pointing instructions for your house say that the 5-lnb dish needs to be pointed at 188 degrees azimuth, 51 degrees elevation and 83 degrees tilt, then that will give you optimum signals. With a very precisely plumb dish, including replumbing as you attach and tighten the monopoles, and the tilt and elevation set very precisely, then it's just a matter of getting the azimuth correct.


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> So you're saying that if a mast is not plumb and I rotate the dish about the mast that the elevation of that dish does not change relative to the plane tangent to the horizon? Is that what you're trying say?


No. I'm not saying that at all. You are correct. Without a plumb mast, changing the azimuth will change the elevation of the dish relative to the plane defined by the horizon at that point on earth.

Additionally, without a plumb mast, there is no easy way to determine what the rough elevation setting should be or what the tilt setting should be, so as I said before, a plumb mast makes it much easier to do the rough aim and get a lock on the 101 signal in the first place, but past that step, it has ZERO effect on the fine tuning process.



> BTW, the fact that the earth is round and plumb is relative to given area is why there are different dish position settings based on area.
> 
> Mike


Yes, because it's easy to calculate those settings if the mast is plumb, which makes setting the right rough elevation and tilt in the first place very easy, which it turn makes finding the right rough azimuth setting very easy, but past that point, plum doesn't matter.


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## cartrivision (Jul 25, 2007)

RobertE said:


> What your saying is absolutely true in regards to a single sat dish (circular polarity not linear). The relative axis for AZ/EL vs the true axis really makes no difference. You can have the dish mounted all sorts of funky ways and still be able to get a good signal.
> 
> Things get real complicated when dealing with a multisat dish such as the slimline. When doing the fine adjustments to say the AZ, your also changing the EL, while it won't affect the 101 a whole lot, it can have pretty dramatic results on the 119. Same for EL affecting the AZ.


That is correct. With a plumb mast it is very easy to calculate the correct rough elevation, tilt, and azimuth, settings for the dish, and without a plumb mast, there's no easy way to determine what those settings should be in order to get a rough aim lock on the 101 sat.



> Can it be done? Sure. Is it as simple as you make it out to be? Absolutely not.


I never said that EVERYTHING was just simple with an out of plumb mast. In fact, I've said the opposite. I've said that it changes the rough aiming procedure from simple to not so simple. What it doesn't do though is change how the fine tuning is done. That remains just as "simple" as it is with a plumb mast.

On an out of plumb mount, the az adjust screw still only changes the orientation of the disk along a single plane. *The fact that that single plane is not parallel to the infinite number of planes that are defined by a perpendicular to a plumb pole at any single point on the earth is completely irrelevant though. *

If that previous sentence was not true, and there was only one mast orientation that worked correctly (and the same way everywhere) when doing the fine tune procedures, then a "plumb mast" wouldn't be the correct mast orientation, because EVERY plum mast in every different location on earth is has a different orientation... i.e. they are all pointing in different directions.... none of them are parallel to any other plumb masts, and yet the az/el adjustments all work the same way and are done the same way for every dish everywhere... all with masts pointing in different directions. That 's why the fine tuning on a plumb mast in Alaska works the same way it does on a plumb mast in Florida, even though those two masts would each be about 70 degrees off/different from the orientation of the other mast.


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## netraa (Mar 28, 2007)

Not sure how to break this to you, but plumb is plumb, is plumb.

doesn't matter if your on the moon, florida, alaska, or australia...

Plumb is well... plumb.

You can peak a multisat dish on a out of plumb mast.

However, the Directv published dithering process breaks down if you don't use a plumb mast due to making changes in 2 dimensions but only measuring the changes in one dimension, and only correcting the one dimension you measured ignoring the influences of the other dimension you were moving in.


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## bobnielsen (Jun 29, 2006)

netraa said:


> Not sure how to break this to you, but plumb is plumb, is plumb.
> 
> doesn't matter if your on the moon, florida, alaska, or australia...
> 
> ...


Cartrivision is correct. With the dithering process you are still making adjustments in two orthogonal dimensions so they won't interact, even if the mast isn't plumb (they just won't line up with the traditional definition of azimuth and elevation). Having a plumb mast makes the whole process easier, of course.


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## RobertE (Jun 10, 2006)

:bang

Frak me, just ain't worth it. :nono2:


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## netraa (Mar 28, 2007)

RobertE said:


> :bang
> 
> Frak me, just ain't worth it. :nono2:


Sometimes, it just really isn't, is it?

Mind if i Join you at the wall?:lol:
:bang


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## cartrivision (Jul 25, 2007)

texasbrit said:


> If the mount is not perpendicular, then if you get the correct azimuth setting and then change the elevation, the pointed azimuth of the dish will shift.


That's irrelevant. Yes changing the azimuth on an out of plumb mount will also change the elevation, but you are talking about changing the "elevation" relative to an arbitrary "horizontal plane" that is different at every different location on earth. It doesn't change the "elevation" relative to the orientation of your mast, and that is all that matters. Again... that is why the millions of different plumb masts everywhere are all pointing in different directions and yet the adjustments all work the same for all those masts all pointing in different directions. Every one of them is perpendicular to a differently oriented plane.



> You can still get the dish pointed correctly, it's just that it will take longer and involve multiple corrections.


No it won't involve or require multiple corrections. It will only require one correction in the azimuth plane and one in the elevation plane, regardless if those planes correspond with the true horizontal plane for their particular point on earth.

*Here is way to grasp this simple concept:*

If there is a 50' by 50' square laid out on earth that has two sides that are oriented exactly in a north/south direction and the other two sides go exactly in an east/west direction, and you are standing at any point inside that square and must to get to another exact spot in that square, but you can only move once in a straight line and then only one more time in a straight line that is exactly 90 degrees from the first straight line move, how can it be done?

You can easily do it in only two moves if the first straight line of movement is exactly in the north/south direction, and the second move is in exactly an east/west direction, but you can also just as easily do it in two similar perpendicular moves if the first move is along a line that has sort of a north easterly / south westerly orientation also.

With either starting orientation and first move direction, you move until the destination point is exactly perpendicular to the first line of movement, and then in both cases you move one more time in the perpendicular direction. In the second case, the fact that the first move changes both your north/south position AND changes your east/west position is irrelevant. You still will make the first move to the point where the destination is exactly perpendicular to the destination point (relatine to the line defined by the first direction of movement). That would be the closest that you could possibly get to the destination with that first move. Once you are as close to the destination point as that first straight line move can possibly get you, moving one more time on a perpendicular line towards the destination point will get you exactly to the destination point. No more moves on the other axis will be necessary.

Not coincidently, this example is completely analogous to movement with the az/el adjustments on the Slimline dish mount. One adjustment moves in one direction and the other moves in a direction exactly perpendicular to that first direction (regardless of the orientation of the mount/mast), and just like the "move to the spot in the square" example above, the orientation/direction of that first move can be arbitrary and is irrelevant. All that matters is getting as close to the point in the sky where the satellite is by getting the strongest signal possible with that first movement, and then from that point, doing one (and only one) more movement in a perpendicular direction will get you to the point that is exactly at the location of the satellite.


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## cartrivision (Jul 25, 2007)

netraa said:


> Not sure how to break this to you, but plumb is plumb, is plumb.
> 
> doesn't matter if your on the moon, florida, alaska, or australia...
> 
> Plumb is well... plumb.


Yes it does matter where you are. In every different location, a "plumb" mast points in a different direction, yet all those differently oriented masts work exactly the same when doing the fine tuning adjustment. You adjust tilt once (to get the strongest signal on the 119 sat), you adjust the AZ screw once and you adjust the EL screw once.



> You can peak a multisat dish on a out of plumb mast
> 
> However, the Directv published dithering process breaks down if you don't use a plumb mast due to making changes in 2 dimensions but only measuring the changes in one dimension, and only correcting the one dimension you measured ignoring the influences of the other dimension you were moving in.


No nothing breaks down. The only thing that changes is that the dish movement is no longer moving in a "true" az/el direction as measured relative to the horizontal plane for that location, but that's irrelevant. There is nothing magical about the plane that is defined by the horizon at any arbitrary location on earth. The "horizontal plane" at my location has a completely different orientation that the one at your location, yet neither of them is the "correct plane" that all az/el movements must be relative to.


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## cartrivision (Jul 25, 2007)

bobnielsen said:


> Cartrivision is correct. With the dithering process you are still making adjustments in two orthogonal dimensions so they won't interact, even if the mast isn't plumb (they just won't line up with the traditional definition of azimuth and elevation). Having a plumb mast makes the whole process easier, of course.


Thank you. Somebody gets it! And yes, having a plumb mast does simplify some parts of the dish pointing, because with a plumb mast you can use the calibrated markings on the dish mount to get the rough elevation and tilt correct, so you only have to rotate the dish on the plumb mast until you get a signal from the 101 sat in order to get the initial rough aim of the dish correct. That would be much harder to do without a plumb mast.


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## dennisj00 (Sep 27, 2007)

I'm not an installer but since all of this is somewhat a lot of semantics -- no one has mentioned how OUT of plumb the mast is. . .

you may be able to PEAK signals from multiple sats with an out of plumb mast, but you WON'T be able to MAXIMIZE signals from every sat. Depending on how many sats (degrees of arc) and how big the dish is, you may not get a signal at all on one place or another. It's simple math, the arc you're looking for is skewed if the mast isn't plumb.

Try it on a C-band monster with a slightly out of plumb mast!


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> Yes it does matter where you are. In every different location, a "plumb" mast points in a different direction, yet all those differently oriented masts work exactly the same when doing the fine tuning adjustment. You adjust tilt once (to get the strongest signal on the 119 sat), you adjust the AZ screw once and you adjust the EL screw once.
> 
> No nothing breaks down. The only thing that changes is that the dish movement is no longer moving in a "true" az/el direction as measured relative to the horizontal plane for that location, but that's irrelevant. There is nothing magical about the plane that is defined by the horizon at any arbitrary location on earth. The "horizontal plane" at my location has a completely different orientation that the one at your location, yet neither of them is the "correct plane" that all az/el movements must be relative to.


There is something a little "magical" about the plane in that the elevation, tilt, and azimuth values are calculated based on the orientation of that plane with the orbital plane of the satellites.

Your assertion that the orientation of the mast doesn't matter in the least would suggest that I can rotate my dish over 90° and be able to easily dither it into a perfect signal for all the orbital slots. However, that simply isn't true. The amount of error that can be taken up by the fine adjustment screws is very limited.

The fact is what you're saying is actually true but only within a _very narrow range_ (although the examples and tone are a bit condescending...I'm just sayin' :grin. The design of the dish mount and the AZ/EL assembly will not work correctly if the mast is not relatively close to, if not actually, plumb. Too far out and it won't work at all.

It is also a fact, and you're absolutely correct, that making adjustments to azimuth and elevation are orthogonal to each other no matter what the orientation of the mast. However, with an out of plumb mast, if I change the azimuth it will cause three dimensional movement of the plane of the dish with respect to the true horizontal plane and thus with respect to the orbital plane of the satellites. In this case there actually is something "magical" about the horizontal plane. Since the plane of this dish moves in three dimensions you can never get as good an alignment as you could with a plumb mast. If the mast is plumb and I adjust the azimuth it has negligible effect on elevation or tilt with respect to the horizontal plane and you can get the optimal alignment with the maximum signal strengths.

While, you can do it with the mast out of plumb, it will *never *be as good as it would with a plumb mast.

Mike


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## veryoldschool (Dec 10, 2006)

dennisj00 said:


> I'm not an installer but since all of this is somewhat a lot of semantics -- no one has mentioned how OUT of plumb the mast is. . .
> 
> you may be able to PEAK signals from multiple sats with an out of plumb mast, but you WON'T be able to MAXIMIZE signals from every sat. Depending on how many sats (degrees of arc) and how big the dish is, you may not get a signal at all on one place or another. It's simple math, the arc you're looking for is skewed if the mast isn't plumb.
> 
> Try it on a C-band monster with a slightly out of plumb mast!


"out of plumb" is only limited by the tilt/AZ/EL adjustments you have.

The C-Band is a completely different problem since the dish needs to sweep through an arc to get all the SATs. This movement needs to be "predefined" with the proper mount.


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## RobertE (Jun 10, 2006)

netraa said:


> Sometimes, it just really isn't, is it?
> 
> Mind if i Join you at the wall?:lol:
> :bang


Sure, space is available to the left. The roach coach stops by at 8:30, 12:30 & 4. :grin:


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> There is something a little "magical" about the plane in that the elevation, tilt, and azimuth values are calculated based on the orientation of that plane with the orbital plane of the satellites.


That only matters when you are setting az,el, and tilt to indicated value such as when you are doing the rough aim and set elevation and tilt by using the calibrated markings on the dish mount. Those calibrated markings are only correct when the mast is plumb. I have acknowledged that point over and over, however past that point, any adjustments that are done are simply by moving the tilt to get the best signal for 119, and then dithering the dish in what is two completely arbitrary oriented planes that have the one restriction that they are perpendicular to each other.

Other than the fact that those two planes of movement are perpendicular to each other, there is nothing else constant about them. They have a completely different orientation in each and every dish installation location, so your claim that there _is_ something magical about any particular orientation of those two perpendicular planes, is absolute illogical nonsense.



> Your assertion that the orientation of the mast doesn't matter in the least would suggest that I can rotate my dish over 90° and be able to easily dither it into a perfect signal for all the orbital slots. However, that simply isn't true.


Sorry but it is true. As I pointed out, a dish mast in Alaska will be almost 90 degrees askew from a dish mast in southern Florida, and yet the fine tuning procedure is exactly the same for both locations.



> The amount of error that can be taken up by the fine adjustment screws is very limited.


That's irrelevant. As long as the dish mast isn't so far out of plumb that it can be pointed to receive the 101 sat using the rough az/el/tilt setting methods, then the limited amount of adjustment necessary to get peak readings can be accomplished with the limited amount of movement that the fine tuning screws provide.



> The fact is what you're saying is actually true but only within a _very narrow range_ (although the examples and tone are a bit condescending...I'm just sayin' :grin. The design of the dish mount and the AZ/EL assembly will not work correctly if the mast is not relatively close to, if not actually, plumb. Too far out and it won't work at all.


Sorry, but again that is complete nonsense...completely unsupported by any logical explanation whatsoever. If I lived in Florida, I could mount a mast that had the same absolute orientation that a plumb mast in Alaska would have, and while that mast would only be elevated about 20 degrees off the horizon in Florida, explain to me why the az/el/tilt fine tuning would somehow not work the in the same way for two dishes that have exactly the same mast orientation.

Also explain to me why despite every plumb DirecTV dish mast having a different mast orientation (in many cases, in excess or 45 degrees of difference), the az/el fine tuning still works the same way an all those different masts that all have very different orientations relative to each other.



> It is also a fact, and you're absolutely correct, that making adjustments to azimuth and elevation are orthogonal to each other no matter what the orientation of the mast. However, with an out of plumb mast, if I change the azimuth it will cause three dimensional movement of the plane of the dish with respect to the true horizontal plane and thus with respect to the orbital plane of the satellites. Since the plane of this dish moves in three dimensions you can never get as good an alignment as you could with a plumb mast. If the mast is plumb and I adjust the azimuth it has negligible effect on elevation or tilt with respect to the horizontal plane and you can get the optimal alignment with the maximum signal strengths.
> 
> Mike


Again, this argument is completely illogical and self contradictory, because while arguing that there is only one "correct" orientation in which the az/el fine tune procedure will work right or best, the argument fails logically because it ignores the fact that in actual practice there is no one "correct" orientation of the masts that everyone uses. They are all in different orientations because they are all set perpendicular to the horizontal plane that has a different orientation in each and every mast location. You can't logically argue that only one orientation works correctly when in actual practice every single mast has a different orientation.... some different by more than 45 degrees.


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## gfrang (Aug 30, 2007)

This is what happened to me,when the installer placed my pole he apparently didn't wait for the cement to dry before installing the dish because it is leaning in the direction were the dish is pointed. So after the 103 sat. went live i was getting dropouts.

So what i did was peak it very carefully using the dither method of course. First i did the the az then el after that i am getting signals in the mid to upper 90s and performs rock solid in bad weather.

Point is even with a dish that is out of plumb i feel it is possible to get a good aim.


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## cartrivision (Jul 25, 2007)

veryoldschool said:


> "out of plumb" is only limited by the tilt/AZ/EL adjustments you have.
> 
> The C-Band is a completely different problem since the dish needs to sweep through an arc to get all the SATs. This movement needs to be "predefined" with the proper mount.


Exactly, and since I have been pointing out how every plumb DirecTV dish mast has a different orientation and points in a different direction, this would be a good place to point out that the old C-Band satellites typically had a "polar mount", which means that unlike the DirecTV dish masts, every C-Band satellite's mast was pointed in exactly the same direction regardless of whether that dish was in Alaska or Florida or anywhere else in the northern hemisphere.

To be more precise, in actual practice the C-Band dishes were mounted on a plumb mast too, but then they had special mounts that essentially created a secondary tilted "pole" that created the polar axis pivot point around which the dish was rotated. That secondary pole or axis is oriented in the exact same direction for every C-band dish, so a C-band dish way up north near the arctic circle would be mounted on a "pole" that was nearly vertical, and a C-band dish located near the equator would be mounted on a "pole" that was nearly horizontal, but they all pointed in exactly the same direction regardless of the installation location.

To search for different satellites, the dish was not rotated on the axis of the plumb mast but around the axis of the polar mast or pivot point.


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## dennisj00 (Sep 27, 2007)

And looking at a subset of that same arc. Skew the arc and you get some good, some bad.


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## cartrivision (Jul 25, 2007)

dennisj00 said:


> I'm not an installer but since all of this is somewhat a lot of semantics -- no one has mentioned how OUT of plumb the mast is. . .
> 
> you may be able to PEAK signals from multiple sats with an out of plumb mast, but you WON'T be able to MAXIMIZE signals from every sat. Depending on how many sats (degrees of arc) and how big the dish is, you may not get a signal at all on one place or another. It's simple math, the arc you're looking for is skewed if the mast isn't plumb.
> 
> Try it on a C-band monster with a slightly out of plumb mast!


The Slimline dish tilt adjustment is used to correct it to the right skew, and unlike C-band dishes, the slimlines don't have to be able to be moved through the arc of satellites that lie along the Clarke Belt. A problem with an out of plumb mast is that setting the dish skew and elevation settings on the dish mount to the settings that are "right" for your zipcode will not work. The settings on those indicators that actually work will be something other than the "right" settings when the mast is not plumb. Those calibrated tilt and elevation degree indicators are only correct if the mast is plumb, so a plumb mast is VERY useful in conjunction with those markings to do the initial rough aiming of the DirecTV dishes, but once you are past that rough aiming, being plumb or out of plumb changes nothing.


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## cartrivision (Jul 25, 2007)

dennisj00 said:


> And looking at a subset of that same arc. Skew the arc and you get some good, some bad.


That's very true for polar mounted C-band dishes, but completely irrelevant to DirecTV dishes, which not only don't depend on polar mounts, they don't even depend on using one common mount orientation.

Every single DirecTV mast and dish mount has a different orientation from every other DirecTV mast and dish mount, and yet they all work the same way and they are all fine tuned in the same way.


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## bobnielsen (Jun 29, 2006)

The Directv (and Dish) mounts use the tilt adjustment to accomplish the same thing (over a very narrow angular range) that a polar mount provides. It works because the satellites involved are not spread out very far. As cartrivision said, the markings on the dish won't be correct with a non-plumb mast.


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> That only matters when you are setting az,el, and tilt to indicated value such as when you are doing the rough aim and set elevation and tilt by using the calibrated markings on the dish mount. Those calibrated markings are only correct when the mast is plumb. I have acknowledged that point over and over, however past that point, any adjustments that are done are simply by moving the tile to get the best signal for 119, and then dithering the dish in what is two completely arbitrary oriented planes that have the one restriction that they are perpendicular to each other.
> 
> Other than the fact that those two planes of movement are perpendicular to each other, there is nothing else constant about them. They have a completely different orientation in each and every dish installation location, so your claim that there _is_ something magical about any particular orientation of those two perpendicular planes, is absolute illogical nonsense.
> 
> ...


You seem to have a problem thinking in three dimensions. Azimuth, tilt, and elevation must be set to a specific orientation in relation to the orbital plane of the satellites and the spread across that orbit. Further they each need to be in a given relationship to each other for a given location on the surface of the planet. That is a fact.

Why is this true? For the same reasons a telescope uses an equatorial mount to follow the path of the stars across the sky. The mount is oriented so the center of rotation telescope is parallel with the rotation of the Earth. In order to do this the mount must first be level and then the North Celestial Pole. The equatorial mount allows the telescope to rotate in one plane to follow a star. The point being it must be plumb first to work. If the mount is plumb and the polar axis is pointed at the North Celestial Pole, you will get identical results no matter where you are on the planet but it must first be plumb. Once aimed at a star you can follow it across the sky while rotating the telescope about a single plane. If the mount isn't level (mast plumb) then rotating the telescope about any of its axes will alter the directions of the other axes.

You are correct in the fact that plumb in Alaska and Florida may be askew by a bunch of degrees of arc. However, you need to understand that it's an important consideration in a spherical coordinate system and the telescope mount must first be plumb before you can set the polar axis of the mount.

Now swap telescope with dish and the exact same concepts apply. If the mast isn't plumb then the mount isn't level. Any adjustments to tilt, azimuth, or elevation will affect the other two, not with respect to each other, but rather with respect to the orbital plane and spread of the satellites (within that spherical frame of reference). This is an inescapable fact that seems lost on you.

BTW, if you go outside right now and rotated the mast of your dish 90°, you will not be able to align it because of the physical limitations of the hardware. There simply isn't enough travel in the mount components to right the dish. There is only so far out of plumb you can be and still be able to move the dish on the mount to get any kind of alignment. Therefore plumb becomes important.

If the mast is out of plumb it'll probably work fine...as long as it's not too out of plumb.

Mike


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## David MacLeod (Jan 29, 2008)

if you shoot the mast and reflector with a 12 gauge slug none of this posturing matters.


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> You seem to have a problem thinking in three dimensions. Azimuth, tilt, and elevation must be set to a specific orientation in relation to the orbital plane of the satellites and the spread across that orbit. Further they each need to be in a given relationship to each other for a given location on the surface of the planet. That is a fact.


Again, you are arguing illogical nonsense. The orbital plane of the satellites is irrelevant because relative to any position on earth, the satellites are not moving, therefore the satellite and dish positions are essentially just two stationary points in space measured relative to any location on earth.



> Why is this true? For the same reasons a telescope uses an equatorial mount to follow the path of the stars across the sky. The mount is oriented so the center of rotation telescope is parallel with the rotation of the Earth. In order to do this the mount must first be level and then the North Celestial Pole. The equatorial mount allows the telescope to rotate in one plane to follow a star. The point being it must be plumb first to work. If the mount is plumb and the polar axis is pointed at the North Celestial Pole, you will get identical results no matter where you are on the planet but it must first be plumb. Once aimed at a star you can follow it across the sky while rotating the telescope about a single plane. If the mount isn't level (mast plumb) then rotating the telescope about any of its axes will alter the directions of the other axes.


More irrelevant points. The DirecTV dish mount does not have to track anything. It's set up once to focus on a group of "fixed" position satellites.



> You are correct in the fact that plumb in Alaska and Florida may be askew by a bunch of degrees of arc. However, you need to understand that it's an important consideration in a spherical coordinate system and the telescope mount must first be plumb before you can set the polar axis of the mount.


Completely irrelevant. The DirecTV dishes and mounts do not require and do not do polar tracking. Drop the telescope analogy. It does not apply.



> Now swap telescope with dish and the exact same concepts apply. If the mast isn't plumb then the mount isn't level. Any adjustments to tilt, azimuth, or elevation will affect the other two, not with respect to each other, but rather with respect to the orbital plane and spread of the satellites (within that spherical frame of reference). This is an inescapable fact that seems lost on you.


Not lost... just noted as irrelevant to the discussion about DirecTV dish masts. Again unlike telescoped which have to oriented on an axis that has the exact same orientation regardless of there in the world the telescope is set up, the DirecTV satellite mounts have no such common mounting axis and in fact, unlike with telescopes, every DirecTV dish moves along axis' that are never oriented in a common direction. You still fail to grasp, and accept that simple fact. DIRECTV MOUNTS ARE ALL ORIENTED ON DIFFERENT AXIS' AND YET THE FINE TUNING ADJUSTMENTS ALL WORK EXACTLY THE SAME WAY REGARDLESS OF THE ORIENTATION OF THE MAST AND DISH MOUNT.

Please stop bringing up different systems such as telescopes which specifically are all oriented on a single common axis and comparing them to a system such as the DirecTV dish aiming mechanism that doesn't use or require a common mount axis like telescopes do. EVERY single DirecTV mount rotates on at least one different axis than any other DirecTV dish mounts do when they are located in a different location. There are very significant differences between the system that DirecTV uses and to the system used for telescopes.

The main significant difference is that a telescope's main axis of rotation in in one location always exactly matches the same axis of rotation of a telescope that is in a different location, and that same statement can't be made for the axis of rotation on a DirecTV dish mount. They are two different systems of aiming to a specific spot in the sky.



> BTW, if you go outside right now and rotated the mast of your dish 90°, you will not be able to align it because of the physical limitations of the hardware. There simply isn't enough travel in the mount components to right the dish. There is only so far out of plumb you can be and still be able to move the dish on the mount to get any kind of alignment. Therefore plumb becomes important.


More irrelevant nonsense. Just because the DirecTV dish mount rough az/el adjustment capability is less that 90 degrees, that fact does ABSOLUTELY NOTHING to support your incorrect premise that having a plumb mast is necessary in order to do the normal az/el fine tuning adjustments, or that an out of plumb mast will mean that any adjustment of the azimuth screw will create a requirement for the adjustment of the elevation screw.



> If the mast is out of plumb it'll probably work fine...as long as it's not too out of plumb.
> 
> Mike


I have no Idea what that statement is supposed to mean exactly, but I'll restate it while being correct and while being more specific... If the mast is out of plumb, fine tuning of the alignment will absolutely work fine (and the same as it works on a perfectly plumb dish), even if the mast is out of plumb by 45 degrees or more, as long as the rough azimuth and elevation adjustments on the dish mount have enough free travel travel to get the 101 LNB of the dish focused on the 101 satellite.

Again, I'll stop arguing this point if you can explain why the fine tuning adjustment procedure works exactly the same way on a plumb mast in Alaska as it does on a plumb mast in Florida, even those two masts are askew from each other by about 70 degrees and even though they share no common axis of rotational whatsoever.


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## Doug Brott (Jul 12, 2006)

Guys .. Must we really take this argument down to the size of a grain of salt?


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> Again, you are arguing illogical nonsense. The orbital plane of the satellites is irrelevant because relative to any position on earth, the satellites are not moving, therefore the satellite and dish positions are essentially just two stationary points in space measured relative to any location on earth.
> 
> More irrelevant points. The DirecTV dish mount does not have to track anything. It's set up once to focus on a group of "fixed" position satellites.
> 
> ...


Here is a dish in Miami and one in Anchorage.

The reason the fine tuning process is the same for each location is because they are pointing in *completely different directions*.

Miami - 33122
Satellite: 101.1W DirecTV 4S, 9S
Elevation: 52.0°
Azimuth (true): 221.1°
Azimuth (magn.): 226.9°

Anchorage - 99501
Satellite: 101.1W DirecTV 4S, 9S
Elevation: 9.9°
Azimuth (true): 127.5°
Azimuth (magn.): 108.1°

There is a fixed quantifiable relationship between azimuth, tilt, and elevation relative to the position and spread of the satellites. The procedures for fine tuning are predicated on the fact that the dish starts with a correct-ish azimuth, elevation, and tilt and not where it is nor how it's mounted. The dang dish could be hung by bungee cords, it really doesn't matter as long as it's pointed at the correct spot in the sky. However, when you start fine tuning the mount being level now becomes important. The fine tuning procedure requires the mast to be plumb, and thus the mount being level, so that tuning one of the parameters doesn't affect the other two. And by that I mean changing the fixed relationship of azimuth, elevation, and tilt in relation the position/spread of the satellites.

You said it yourself. The satellites are in a fixed position relative to the dish. Which is why the equatorial mount and its operation is perfectly analogous to a satellite dish mount and positioning. You don't seem to believe that if the mount isn't level changing one of those three parameters will necessarily change the other two. At least it seems you believe it doesn't matter. It may not on a clear day but lets throw some weather into the mix and see what happens.

Riddle me this. Why does the installation procedure state that the mast being plumb is "*critical*? If I'm completely wrong then what's so critical about it?

Mike


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## veryoldschool (Dec 10, 2006)

MicroBeta said:


> Riddle me this. Why does the installation procedure state that the mast being plumb is "*critical*? If I'm completely wrong then what's so critical about it?
> 
> Mike


The 95 SAT uses a linear polarization [If I've read these threads correctly].
Having this tilted would be a nightmare.
"Teach techs to do all installs the same way".
Curricular polarization doesn't care.


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> Here is a dish in Miami and one in Anchorage.
> 
> The reason the fine tuning process is the same for each location is because they are pointing in *completely different directions*.
> 
> ...


Yikes! That was a lot of hand waving and throwing around of some factual but irrelevant statements without providing any logical substantive support for any of your unsubstantiated assertions. Lets not look at what you said that correct and irrelevant, but let's look at what you said that was just plain wrong:



> The reason the fine tuning process is the same for each location is because they are pointing in *completely different directions*.


Complete nonsense. You still haven't explained why two different masts that are askew from each other both can be fine tuned exactly the same way despite sharing no common adjustment axes. Explain how the "pointing in two different directions" compensates for the fact that the azimuth and elevation adjustments on those two askew dish mounts don't share or move along any common axes. Then answer the following...

Would the fact that the two askew dishes have no common adjustment axes be still be OK if both dishes had to be pointed to one point in the sky that was in the exact same direction from both dishes (such as a star in the sky)? If not, why not? If yes, then how do the dissimilar/askew adjustment axes of both dishes somehow get compensated for when the dishes both are pointing in the exact same direction, since your assertion was that it was that the fact that they are pointed in a different directions that made the two askew mounts work in the same way for fine tuning despite their different orientations. You will not be able to answer these questions logically because there is no logical answer that does not create a contradiction to your "pointing in different directions" theory.



> You said it yourself. The satellites are in a fixed position relative to the dish. Which is why the equatorial mount and its operation is perfectly analogous to a satellite dish mount and positioning.


There is a HUGE problem with your last sentence there. Besides the fact that the DirecTV dish fine tuning process does not require or depend on an equatorial mount, additionally, the DirecTV dish mounts are *NOT* equatorial mounts, they are alt-azimuth mounts which not only move on a completely differently oriented pair of axes as compared to equatorial mounts, but no two alt-azimuth mounts move on an identical pair of axes when each of their reference points is a plumb mast at two different locations on earth. They are two completely different systems... one with a single common axis orientation that is exactly the same when it is set up at any location on earth, and another system that has millions of different axis orientations that change with the setup location on earth, so there isn't a valid analogy there despite your assertion that the two very dissimilar systems are "perfectly analogous".



> You don't seem to believe that if the mount isn't level changing one of those three parameters will necessarily change the other two. At least it seems you believe it doesn't matter.


 I believe that changing the azimuth DirecTV dish mounted on an out of plumb mast does also change the elevation, but it doesn't matter because that "elevation" is nothing but an angular measurement from an arbitrarily oriented plane. Having an out of plumb mast changes the orientation of that arbitrary plane, but that different reference point doesn't change the fundamentals of geometry, which is what dictates how the az/el adjustments on the dish mount work and affect the fine alignment process. The orientation of that reference plane is irrelevant. Adjusting the dish to point to some location at some angular offset from an arbitrarily oriented plane obviously will be done the exact same way using the same fundamentals of geometry if and when the arbitrary orientation of that reference plane changes, and THAT is why the fine tuning process works exactly the same from any location (or with any out of plumb mast) despite the fact that every different location (or the lack of a plumb mast) will mean that there is a different orientation of that reference plane.



> Riddle me this. Why does the installation procedure state that the mast being plumb is "*critical*? If I'm completely wrong then what's so critical about it?


 Iv'e answered this question several times already, but I'll answer it again. Being plumb is critical because without a plumb mast, the elevation and tilt markings on the dish mount would be wrong and completely useless, making it very difficult to do the initial rough aiming of the dish which has to be done before the fine tuning is done. The importance of a plumb mast becomes irrelevant though when doing the fine tuning adjustment since the fine tuning procedure doesn't use or depend on those elevation markings on the dish mount. If you are roughly pointed towards the 101 satellite and getting some level of signal, having a plumb mast (and correct elevation markings that a plumb mast makes possible) is no longer a requirement.


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## Stuart Sweet (Jun 19, 2006)

Folks, I'm all for healthy discussion here but let's try not to be so rude about it. How about sticking to the facts without calling other people's posts "nonsense?" 

I think this is a very useful thread but I will not hesitate to close it if you cannot play nice.


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## bobcamp1 (Nov 8, 2007)

Cartrivision is right. I've successfully tweaked an installation that wasn't plumb. My previous house wasn't plumb where I chose to put the dish. It was off half a bubble. I thought about using wood shims to help level the pole. But I didn't have to. It worked.

Actually, due to the nature of DBS, you don't need absolute maximum signal strength. You just need "good enough". It would have took me 5 minutes if I didn't try to maximize the signal. The initial signal strengths were in the 30s and I got it to mid 80s almost right away. But I'm an engineer, and that was when I was married with no kids, so I played a little. I'm guessing that people who do this for a living could do it faster than I could. It took me 30 minutes.

Remember, the pole is irrelevant -- all that matters is how the dish ends up pointing at the sky. Since neither the dish nor the satellites move once you figure out the settings, all that matters is getting it locked in any way you can then leaving it alone.

And there is no such thing as perfectly plumb. So how far off can you be? Simple -- when the fine adjustment is moved all the way to one end and you still don't have a decent signal, or you've run out of patience and foul language, it's time to fix the pole.


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> Yikes! That was a lot of hand waving and throwing around of some factual but irrelevant statements without providing any logical substantive support for any of your unsubstantiated assertions. Lets not look at what you said that correct and irrelevant, but let's look at what you said that was just plain wrong:
> 
> Complete nonsense. You still haven't explained why two different masts that are askew from each other both can be fine tuned exactly the same way despite sharing no common adjustment axes. Explain how the "pointing in two different directions" compensates for the fact that the azimuth and elevation adjustments on those two askew dish mounts don't share or move along any common axes. Then answer the following...
> 
> Would the fact that the two askew dishes have no common adjustment axes be still be *OK if both dishes had to be pointed to one point in the sky that was in the exact same direction from both dishes (such as a star in the sky)? If not, why not?* If yes, then how do the dissimilar/askew adjustment axes of both dishes somehow get compensated for when the dishes both are pointing in the exact same direction, since your assertion was that it was that the fact that they are pointed in a different directions that made the two askew mounts work in the same way for fine tuning despite their different orientations. You will not be able to answer these questions logically because there is no logical answer that does not create a contradiction to your "pointing in different directions" theory.


My "pointing in a different direction" explanation is absolutely correct. Further, a dish in Miami and a dish in Anchorage are *already* pointed at essentially the same point in the sky...at the satellites. The sky is a sphere around the Earth. If you aim at a single spot in the sky (such as a star)from two different locations you will be pointing in two different directions with respect to the local area. It is NOT possible to have two widely spread locations point at the same point in the sky and be pointing in the same direction with respect to the local area...not even for a star.

To be perfectly clear, and this is important to understand, this is not my assertion nor is it my opinion. Rather it is a mathematically fact that can be found in any calculus or astronomy text book (among others). It is simple mathematics and therefore it is completely logical and is SUBSTANTIATED by any number of sources on the subject. So, as you can see, the dishes being pointed in different directions (with respect to the local area) is *necessary* to aim at the same spot in the sky (where the satellites are) and is IN NO WAY "complete nonsense". Further, this is easily verifiable.

Now, as to how this relates to your original question; the fine tuning process is just that, fine tuning. The procedure fine tunes the position of the dish *after* it has been correctly aimed at the satellites. The initial aiming of the dish is the only thing that's different between different locations. All the fine tuning process does is make small adjustments to an already aimed dish to peak the signals. *Again, only the initial aiming of the dish is dependent upon location*. Since fine tuning *does not* aim the dish at the satellites it is therefore independent of location. If I didn't properly explain that the first time, I appologize.



> There is a HUGE problem with your last sentence there. Besides the fact that the DirecTV dish fine tuning process does not require or depend on an equatorial mount, additionally, the DirecTV dish mounts are *NOT* equatorial mounts, they are alt-azimuth mounts which not only move on a completely differently oriented pair of axes as compared to equatorial mounts, but no two alt-azimuth mounts move on an identical pair of axes when each of their reference points is a plumb mast at two different locations on earth. They are two completely different systems... one with a single common axis orientation that is exactly the same when it is set up at any location on earth, and another system that has millions of different axis orientations that change with the setup location on earth, so there isn't a valid analogy there despite your assertion that the two very dissimilar systems are "perfectly analogous".
> 
> Iv'e answered this question several times already, but I'll answer it again. Being plumb is critical because without a plumb mast, the elevation and tilt markings on the dish mount would be wrong and completely useless, making it very difficult to do the initial rough aiming of the dish which has to be done before the fine tuning is done. The importance of a plumb mast becomes irrelevant though when doing the fine tuning adjustment since the fine tuning procedure doesn't use or depend on those elevation markings on the dish mount. If you are roughly pointed towards the 101 satellite and getting some level of signal, having a plumb mast (and correct elevation markings that a plumb mast makes possible) is no longer a requirement.


I disagree with all this (and it's basically covered above...though not completely) but it's not worth discussing.

Mike


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## bobcamp1 (Nov 8, 2007)

cartrivision said:


> Iv'e answered this question several times already, but I'll answer it again. Being plumb is critical because without a plumb mast, the elevation and tilt markings on the dish mount would be wrong and completely useless, making it very difficult to do the initial rough aiming of the dish which has to be done before the fine tuning is done.


They aren't completely useless, they still provide a ball park estimate for which direction the dish has to be pointing. Plus its possible to be a little off plumb, adjust the dish to the recommended settings, and have a very low (but not zero) signal strength.

If you get NO signal strength initially, you have a lot of work to do. You'll have to sweep the dish and that takes a lot of time. Since D* installers never seem to have enough time, D* states that the pole has to be "perfectly plumb" to save them time, which is critical. Since we also know some installers like to cut corners, if "perfectly plumb" ends up being "mostly plumb", that's OK -- the dish has adjustments that can be made.

DIY installers have more time, so plumbness (?) isn't as critical for them. They can spend an hour or two adjusting the dish and not get yelled at by their supervisor (although maybe their wife will yell at them instead).


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## veryoldschool (Dec 10, 2006)

:bang

I think point/couterpoint has gone on long enough to lose most readers.

If you have a moving dish, you need to align the mount such that the sweep will be aligned with the SATs.
DirecTV dishes:
If you have a single LNB [101] dish, you "could mount it" sideways or maybe even upside down, and align it, though it would be a PITA.
With 2 or more LNBs:
If the mast were leaning forward or backward, the EL would need to be adjusted to compensate.
If the mast was leaning right or left, the tilt would need to be adjusted to compensate.
If the mast were leaning "both ways", then both would need to be adjusted.
The settings given for any location are just the "rough starting points".
The more you deviate from the "straight and narrow", the longer/harder it will be to align the dish.
"Fine tuning" is simply that. If you run out of adjustment, you need to go back to the course adjustments and then come back to the fine adjustments.
The 95 SAT isn't as forgiving as it's a linear polarization and not curricular as the others are.


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## wildbill129 (Dec 22, 2006)

veryoldschool said:


> :bang
> 
> I think point/couterpoint has gone on long enough to lose most readers.


Ya think?:new_sleep


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## Whodo (May 15, 2007)

veryoldschool said:


> :bang
> 
> I think point/couterpoint has gone on long enough to lose most readers.


I am following along without any problem.

Personally I would like to see a few math formulas presented. True this would probably lose most people but for those of us that understand it would be nice.


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## veryoldschool (Dec 10, 2006)

Whodo said:


> I am following along without any problem.
> 
> Personally I would like to see a few math formulas presented. True this would probably lose most people but for those of us that understand it would be nice.


What math would you like to see?
Point the dish at the SAT and you have a signal. The better you point it, the better the signal.


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## HoTat2 (Nov 16, 2005)

I also think it's worth pointing out here that the "polar" or "equatorial" mount used by C-band dishes is actually modified from the astronomical type somewhat since the satellite or Clarke belt is rather close to the earth in terms of astronomical distances. Therefore a slight declination offset of the dish from the polar axis is needed depending upon the latitude of the dish's location north or south of the equator because the dish is actually looking downward at an angle to the satellite geosynchronous arc from the northern and southern latitudes.

Thus as the dish sweeps to position for different satellites it needs to follow more of an elliptical path instead of a circular one as would be described by a movable dish at the equator.

For celestial objects so far away that every latitude on earth may be conveniently viewed as the same point, declination offset angles are so tiny that they are irrelevant. But for close in objects (comparatively speaking) like geosynchronous satellites, it is.


----------



## gfrang (Aug 30, 2007)

Whodo said:


> I am following along without any problem.
> 
> Personally I would like to see a few math formulas presented. True this would probably lose most people but for those of us that understand it would be nice.


Are you good at math ? well figure this out, the sats.are 23,000 mi up in space just this side of the equator. Trig it out at your location and find out the actual distance.
Its like hitting a needle in a haystack.


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## bobcamp1 (Nov 8, 2007)

gfrang said:


> A
> Its like hitting a needle in a haystack.


Nope, it's actually easier than that. You have around +/- 3 degrees on elevation and a little more than that on the azimuth (at least it feels that way to me) for the 101 to get any signal. Then tune by +/-1 degree to peak it. With a little practice, you can get really good at it.

You don't even have to peak all the satellites at the same time. Being near the peak is good enough.


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## BKC (Dec 12, 2007)

I'm glad this is cleared up.


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> My "pointing in a different direction" explanation is absolutely correct.


 No, it's complete nonsense that you cannot support. Every time I post an example that contradicts that nonsensical theory, you fail to address it and fail to state or show why my counter-example is invalid.



> Further, a dish in Miami and a dish in Anchorage are *already* pointed at essentially the same point in the sky...at the satellites. The sky is a sphere around the Earth.


Are you serious??? The sky is not a sphere around the earth, it's a 3D space of infinite proportions/distances in all 3 dimensions.



> If you aim at a single spot in the sky (such as a star)from two different locations you will be pointing in two different directions with respect to the local area. It is NOT possible to have two widely spread locations point at the same point in the sky and be pointing in the same direction with respect to the local area...not even for a star.


First of all, stars in the sky are so far away that they appear in the same direction from any observation point on earth at any given time. The nearest stars are trillions of miles away. With something that far away, moving the observation location by a few thousand miles does not effectively change the direction of observation.

A rough analogy would be if someone pointed a telescope at an object 5 miles away and had it centered in the telescope's sight, and then the telescope's tripod was moved left or right by about 1/1,000 of an inch. That movement of the observation position would not effectively change the direction that the telescope had to be pointed to keep that object 5 miles away centered in the telescope's sight.

That is why a telescope on a polar mount can simply be rotated around its polar axis in the opposite direction of the earth's rotation in order to keep the stars that are being observed from moving relative to the observation point. Even though the location of the telescope might be changing by thousands of miles over several hours due to the earth's rotation, neither of the aiming axes (the right ascension or declination) on the telescope have to be changed to keep tracking the star. The telescope is only rotated around its polar axis.

This is one of the most basic principals of astronomy, and you trying to state something that contradicts it tells me one of two things&#8230;

Either you tried to contradict this well known scientific principal because you knew that it completely invalidates your "looking in different directions" explanation for why the dish fine tuning adjustments work the same everywhere despite the fact that every single dish mount uses a different reference plane for what they call azimuth and elevation.

The other explanation for why you tried to contradict that simple well established fact is because you don't really have any understanding of some of the basic scientific principals that govern this discussion, despite you trying to project a pretense that you do.

Your "the sky is a sphere" statement was a glaring example of your misstatements and or lack of understanding about of some of the most basic scientific principals behind what is being discussed here.



> To be perfectly clear, and this is important to understand, this is not my assertion nor is it my opinion. Rather it is a mathematically fact that can be found in any calculus or astronomy text book (among others). It is simple mathematics and therefore it is completely logical and is SUBSTANTIATED by any number of sources on the subject. So, as you can see, the dishes being pointed in different directions (with respect to the local area) is *necessary* to aim at the same spot in the sky (where the satellites are) and is IN NO WAY "complete nonsense". Further, this is easily verifiable.


Again, you just stating that something is a fact backed by mathematics and astromomy books, is not proof of anything without specifically showing how it applies to the specific situation being discussed or showing how it backs up some of your stated theories, and given some of your past statements like "the sky being a sphere", any statement of "fact" that you give without a reference or specific example demonstrating how it applies and backs up your theory, really holds very little credibility.



> Now, as to how this relates to your original question; the fine tuning process is just that, fine tuning. The procedure fine tunes the position of the dish *after* it has been correctly aimed at the satellites. The initial aiming of the dish is the only thing that's different between different locations.


No that's not the only thing that is different between two different dish locations. The orientation of the mast is different in every location, and that means that every different location uses a different reference plane from which their elevation and azimuth fine tuning movements are referenced. From some locations, the dish's az/el adjustment coordinates are approximately parallel and perpendicular to the arc of the imaginary Clark Belt in the sky on which the satellite is located, and from some locations the dish's az/el adjustment coordinates move the dish at about a 45 degree angle to the arc of the Clarke Belt. Every different installation has a different reference point and orientation for their coordinate system that is used in the fine tuning process and yet they all still work the same way without sharing a common set of axes for their adjustment coordinate system.

I claim that the above facts demonstrate that the orientation of the mast is irrelevant to the process of fine tuning.

You've tried and repeatedly failed to explain while the orientation of the mast matters at a given location. You and others have claimed that the mast has to be plumb, or else fine tuning won't work the same... even though everything still works the same for other locations where the mast orientation is different and significantly out of skew from _your_ plumb mast.

Your last explanation of "because they were pointing in different directions" was not only nonsensical, but completely unsupported by even a simple example of how it was a valid explanation. Then there was the problem that when two dishes are both looking in the same direction, the "looking in different directions" explanation can't be used to explain why things still worked the same with different mast orientations, so the theory doesn't even withstand a test for basic logic and consistency.



> All the fine tuning process does is make small adjustments to an already aimed dish to peak the signals. *Again, only the initial aiming of the dish is dependent upon location*. Since fine tuning *does not* aim the dish at the satellites it is therefore independent of location. If I didn't properly explain that the first time, I appologize.


I have no idea what you are trying to say here, but fine tuning absolutely is "aiming the dish at the satellites". Furthermore stating that the fine tuning process is independent of location effectively supports my contention that it is independent of mast orientation, since an independent location also has an independent mast orientation.



> cartrivision said:
> 
> 
> > There is a HUGE problem with your last sentence there. Besides the fact that the DirecTV dish fine tuning process does not require or depend on an equatorial mount, additionally, the DirecTV dish mounts are NOT equatorial mounts, they are alt-azimuth mounts which not only move on a completely differently oriented pair of axes as compared to equatorial mounts, but no two alt-azimuth mounts move on an identical pair of axes when each of their reference points is a plumb mast at two different locations on earth. They are two completely different systems... one with a single common axis orientation that is exactly the same when it is set up at any location on earth, and another system that has millions of different axis orientations that change with the setup location on earth, so there isn't a valid analogy there despite your assertion that the two very dissimilar systems are "perfectly analogous".
> ...


So you disagree with "ALL" of that?? Let's review all of that&#8230;.

The DirecTV aiming/adjustments do not depend on an equatorial mount... that is a fact.

The DirecTV dish mount is not an equatorial mount.... that is a fact.

Every az/el mount of every DirecTV dish is in a unique orientation and it's adjustment axes are in a completely different orientation (move the dish in different directions) than every other dish installed at a different location&#8230; that is fact.

No two alt-azimuth mounts move on an identical pair of axes when each of their reference points is a plumb mast at two different locations on earth&#8230;. that is a fact.

Telescope mounts are a system with a single common axis orientation that is exactly the same when it is set up at any location on earth, and the DirecTV mount system is a completely different system that has millions of different axis orientations that change with (are dependent upon) the setup location on earth&#8230; that is a fact.

A plumb mast is important for the reason that without a plumb mast, the elevation and tilt markings on the dish mount would be wrong and completely useless, and the rough aiming would be very difficult&#8230;. that is a fact.

The previously stated importance of a plumb mast becomes irrelevant when doing the fine tuning adjustment since the fine tuning procedure doesn't use or depend on those elevation markings on the dish mount&#8230;. that is a fact.

So since you disagree with "all" of that, show how any of it isn't factual.



> &#8230;.but it's not worth discussing.
> 
> Mike


It's a fun intellectual exercise, which in my book makes it well worth discussing, but you really need to study up on some of the most basic principals that apply to this discussion, because much of what you have said to support your theories has been completely incorrect, or if correct, illogically applied to a non-analogous situation where it doesn't really apply.


----------



## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> No, it's complete nonsense that you cannot support. Every time I post an example that contradicts that nonsensical theory, you fail to address it and fail to state or show why my counter-example is invalid.
> 
> Are you serious??? The sky is not a sphere around the earth, it's a 3D space of infinite proportions/distances in all 3 dimensions.


Of course I'm serious. "In astronomy and navigation, the celestial sphere is an imaginary sphere of arbitrarily large radius, concentric with the Earth and rotating upon the same axis." This sphere is the spatial system by which the location all objects in the sky are determined. Which means my counter example is completely valid. See below for supporting evidence.



> <snip>It's a fun intellectual exercise, which in my book makes it well worth discussing, *but you really need to study up on some of the most basic principals that apply to this discussion*, because much of what you have said to support your theories has been completely incorrect, or if correct, illogically applied to a non-analogous situation where it doesn't really apply.


I'm tired of your rude, condescending attitude. I answered your post with the facts and how to find substantiation for that information. I didn't discuss your points directly because they are factually incorrect and without basis for determining where to aim and fine tune a dish. The fact is YOU need to do some studying. The following websites will explain how objects are positioned in the sky. Further, they will explain how to determine the direction from which to view any object in the sky. This direction is how the elevation and azimuth of the dish are determined and yes, it's based on the sky being a SPHERE.

http://en.wikipedia.org/wiki/Celestial_coordinate_system
http://csep10.phys.utk.edu/astr161/lect/time/coordinates.html
http://www.astroleague.org/al/astrnote/astnot11.html
http://visual.merriam-webster.com/astronomy/astronomical-observation/celestial-coordinate-system.php
http://www2.jpl.nasa.gov/basics/bsf2-1.php
http://www.economicexpert.com/a/Celestial:coordinate:system.htm
http://www.statemaster.com/encyclopedia/Celestial-coordinate-system
http://physics.gmu.edu/~hgeller/astr402/CelestNavig15.ppt#1
http://www.angelfire.com/nt/navtrig/E3.html
http://www.astronexus.com/node/38
http://adsabs.harvard.edu/full/1927PGro...41Q...9.
http://www.absoluteastronomy.com/topics/Azimuth
http://www.statemaster.com/encyclopedia/Azimuth
http://omniweb.gsfc.nasa.gov/vitmo/cgm_vitmo.html
http://seds.org/~spider/spider/ScholarX/coords.html
http://library.thinkquest.org/29033/begin/coordinate.htm
http://encyclopedia2.thefreedictionary.com/equatorial+coordinate+system
http://astronomy.nmsu.edu/holtz/a535/supplement/node1.html

I'm really sorry but I'm not going to discuss this with you any further. You seem incapable of having a civil discussion and I'm having no more to do with it.


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## Mike Bertelson (Jan 24, 2007)

Whodo said:


> I am following along without any problem.
> 
> Personally I would like to see a few math formulas presented. True this would probably lose most people but for those of us that understand it would be nice.


Here are a couple of nice explainations of the coordinate system that positions celestial objects in the sky with a little of the math too . They show how parameters such as declination and right ascension are determined. Using that stuff you and input time and location to find the elevation and azimuth to look at any object in the. Since geostationary satellites are at a fixed spot in that sky, determining azimuth and elevation is easier because you only have to take into account your location. Time doesn't factor into it so the calculations are a lot easier.

http://en.wikipedia.org/wiki/Celestial_coordinate_system
http://www2.jpl.nasa.gov/basics/bsf2-1.php
http://adsabs.harvard.edu/full/1927PGro...41Q...9. 
http://omniweb.gsfc.nasa.gov/vitmo/cgm_vitmo.html
http://physics.gmu.edu/~hgeller/astr402/CelestNavig15.ppt#1
http://astronomy.nmsu.edu/holtz/a535/supplement/node1.html

Speaking of finding elevation and azimuth, this is one of my favorite sites for that; the United States Naval Observatory. I punch in latitude, longitude, and UCT and it tells me where to look in the sky. I really like this site for finding the planets during the year. There's that really bright star in the east just before sunrise this time of year; this will tell you what it is.  The USNO has a lot of other apps on line that are pretty cool so surf their site. 

http://aa.usno.navy.mil/data/docs/celnavtable.php

Using the USNO site you can see just how different the directions to view a star or planet is from different locations and the same UCT. Sometimes how you can't see them at certain times of the year. 

Here's a good site to follow satellites.

http://science.nasa.gov/realtime/JTrack/3D/JTrack3D.html

Some of these links have equations to demonstrate the concepts. I hope this is the info you're looking for. Understanding how azimuth, elevation, and tilt are determined helps in understanding why things work the way they do.

Mike


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## joe diamond (Feb 28, 2007)

Nobody has mentioned that the dish is a parabola (parabolic antenna) that will bounce a signal from whatever angle to a known focus point. The exact position of the LNB is critical because that is the point where all signals will bounce from the dish.

The reverse example would be a car headlight. The light source is focused on a parabolic mirror and reflects the light out in a straight line which is focused by the headlight lens.

So close enough works. "Plumb" is concept from plane geometry which also is close enough for work on a sphere.

Joe


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## Mike Bertelson (Jan 24, 2007)

joe diamond said:


> Nobody has mentioned that the dish is a parabola (parabolic antenna) that will bounce a signal from whatever angel to a known focus point. The exact position of the LNB is critical because that is the point where all signals will bounce from the dish.
> 
> The reverse example would be a car headlight. The light source is focused on a parabolic mirror and reflects the light out in a straight line which is focused by the headlight lens.
> 
> ...


That's true. You're correct. If the mast isn't plumb (and thus the mount isn't level) you can get it close enough. IMHO, I'd rather have it plumb. It's the difference between good enough and near bullet proof. 

Although, I'd have to say that if the bubble is anywhere within the circle, any error in fine tuning is probably negligible. How far that is I don't have a clue. I'll guess that if the bubble is half out of the circle, it's probably too much...but that's just a guess. :grin:

Mike


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## joe diamond (Feb 28, 2007)

MicroBeta said:


> That's true. You're correct. If the mast isn't plumb (and thus the mount isn't level) you can get it close enough. IMHO, I'd rather have it plumb. It's the difference between good enough and near bullet proof.
> 
> Although, I'd have to say that if the bubble is anywhere within the circle, any error in fine tuning is probably negligible. How far that is I don't have a clue. I'll guess that if the bubble is half out of the circle, it's probably too much...but that's just a guess. :grin:
> 
> Mike


Ah yes!

The little bubble toy...if used properly it is a time saver.
Crank down the mast bolts and get everything tight...look again after all work is done. If something has shifted....physically bend the mast to give plumb and regain the signal you have tuned.

I have fixed many impossible LOS deals where someone had inserted the bubble toy into the mast incorrectly. That will put you well and truly into the deep do do.

I set the mast with a clinometer and give the bubble toy to the kids. Just a habit; and it allows running the cables up through the mast.

Joe


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## Mike Bertelson (Jan 24, 2007)

joe diamond said:


> Ah yes!
> 
> The little bubble toy...if used properly it is a time saver.
> Crank down the mast bolts and get everything tight...look again after all work is done. If something has shifted....physically bend the mast to give plumb and regain the signal you have tuned.
> ...


That's certainly a more accurate way to setup the dish.

I'm curious, in your rework due to the bubble level being use improperly, how far out was the mount from level and how much does that affect loss of signal issues?

Mike


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## BennyGregg (Jul 17, 2009)

Since the my pole mount is not plumb, the approach I used to align my dish was several sequential adjustment and dithering cycles. That is, I would adjust the tilt for maximum signal, dither the elevation and then the azimuth. Repeat several times until no further adjustment of dish is made when dithering.

Is this the best method to align a dish on a mast that is not plumb?


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## veryoldschool (Dec 10, 2006)

BennyGregg said:


> Since the my pole mount is not plumb, the approach I used to align my dish was several sequential adjustment and dithering cycles. That is, I would adjust the tilt for maximum signal, dither the elevation and then the azimuth. Repeat several times until no further adjustment of dish is made when dithering.
> 
> Is this the best method to align a dish on a mast that is not plumb?


Yes, but if you needed to do this all day long, for a living, you'd set all your masts to plumb and make the process much quicker.


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## gfrang (Aug 30, 2007)

BennyGregg said:


> Since the my pole mount is not plumb, the approach I used to align my dish was several sequential adjustment and dithering cycles. That is, I would adjust the tilt for maximum signal, dither the elevation and then the azimuth. Repeat several times until no further adjustment of dish is made when dithering.
> 
> Is this the best method to align a dish on a mast that is not plumb?


That is exactly what i did to align my dish mounted on a pole that was out of plumb,the only i did different was do the azimuth first but i am not sure if that really matters.


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## veryoldschool (Dec 10, 2006)

gfrang said:


> That is exactly what i did to align my dish mounted on a pole that was out of plumb,the only i did different was do the azimuth first but i am not sure if that really matters.


Sometimes I put my right shoe on first, sometimes my left. Once I've got both on, it doesn't matter.


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## joe diamond (Feb 28, 2007)

MicroBeta said:


> That's certainly a more accurate way to setup the dish.
> 
> I'm curious, in your rework due to the bubble level being use improperly, how far out was the mount from level and how much does that affect loss of signal issues?
> 
> Mike


I am going to guess about ten degrees. But it is not just the amount...it is also the unknown , random direction that the thing has been over pushed into the mast.

This issue is shown in picture form in the assembly instructions. Directv has stopped allowing DIY installations of the HD dishes. Only their in house dudes have access to this stuff.

Still the problem persists. It produces enough of an error that the published az & el are not close enough to produce any signal.

Joe


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## joe diamond (Feb 28, 2007)

veryoldschool said:


> Sometimes I put my right shoe on first, sometimes my left. Once I've got both on, it doesn't matter.


I agree on the shoe part..........For sat dishes I like to do the az first and then the el. If you have the dish head too loose during tuning the el will change when you tighten up the bolts. You can readjust the el after the bolts are tight if necessary. The side mounted head bolts help with this on the Ka/Ku dishes.

And also...once the installation site is in the rear view mirror you can even take off your shoes. It doesn't matter.

Joe


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## HoTat2 (Nov 16, 2005)

joe diamond said:


> Nobody has mentioned that the dish is a parabola (parabolic antenna) that will bounce a signal from whatever angle to a known focus point. The exact position of the LNB is critical because that is the point where all signals will bounce from the dish.
> 
> The reverse example would be a car headlight. The light source is focused on a parabolic mirror and reflects the light out in a straight line which is focused by the headlight lens.
> 
> ...


Just for additional accuracy, while the headlight analogy is basically a valid one. The situation with the dishes used by DirecTV and other DTH services as well as some used by Ku band commercial FSS systems is somewhat different in that they use a class of dishes called an "Offset Dish," which as illustrated by the third diagram from the left below, the face of the dish does directly face the satellite. But is inclined at an obtuse angle with respect to it.










I assume that the coordinates for elevation given by the DirecTV receiver, dishpointer.com (when the dish type is specified), etc., for dish alignment take this offset factor into account of course.


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## veryoldschool (Dec 10, 2006)

joe diamond said:


> I agree on the shoe part..........For sat dishes I like to do the az first and then the el. If you have the dish head too loose during tuning the el will change when you tighten up the bolts. You can readjust the el after the bolts are tight if necessary. The side mounted head bolts help with this on the Ka/Ku dishes.
> 
> And also...once the installation site is in the rear view mirror you can even take off your shoes. It doesn't matter.
> 
> Joe


I was more referring to the dithering, than the course settings. AZ first makes soooo much more sense.


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## BennyGregg (Jul 17, 2009)

> Yes, but if you needed to do this all day long, for a living, you'd set all your masts to plumb and make the process much quicker.


My out of plumb mast was a result of a free professional installation.


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## veryoldschool (Dec 10, 2006)

BennyGregg said:


> My out of plumb mast was a result of a free professional installation.


"Don't get me started on Ironwood" [again], as it won't be pretty.  :lol:


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## gfrang (Aug 30, 2007)

BennyGregg said:


> My out of plumb mast was a result of a free professional installation.


Mine too as a result of hanging the dish before the cement cured.


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## Mike Bertelson (Jan 24, 2007)

My installer spent more time plumbing the mast then he did peaking the dish. Consequently, all my signal strengths are about as good as they can be. 

Mike


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## veryoldschool (Dec 10, 2006)

This thread title is well suited.

Maybe we can get Jamie & Adam to do a Mythbusters show to put this to rest.


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## joe diamond (Feb 28, 2007)

veryoldschool said:


> I was more referring to the dithering, than the course settings. AZ first makes soooo much more sense.


About this dithering?

Is that like the little poosh west from the 101 peak?

Or is that what customers do after you cut of their fingers to make them stop looking at the numbers?

I just don't keep up on the technical bulletins.

Joe


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## gfrang (Aug 30, 2007)

veryoldschool said:


> This thread title is well suited.
> 
> Maybe we can get Jamie & Adam to do a Mythbusters show to put this to rest.


It was already on the History Channel Life After People ware the only thing left after we are gone is sat. dishes and cockroaches.


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## veryoldschool (Dec 10, 2006)

joe diamond said:


> About this dithering?
> 
> Is that like the little poosh west from the 101 peak?
> 
> ...


I think I've read your "poosh" west, and if anything you're "just lucky".
I read another post sometime back where "you know you're centered" if you use your thumb and press the dish up/down, right/left and see the signal drop. If it doesn't [or goes up] then you're not centered.
Besides "dithering about", the term is used to describe finding the edges of the beam and then splitting the distance in half. Ku beams are fairly "pointed" so you can find the peak/center easy, while Ka aren't as much and you get a better idea by using the edges.


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## longrider (Apr 21, 2007)

joe diamond said:


> This issue is shown in picture form in the assembly instructions. Directv has stopped allowing DIY installations of the HD dishes. Only their in house dudes have access to this stuff.
> 
> Joe


What do you mean 'stopped allowing'? Solid Signal still lists the AU9 as in stock. I'm not concerned unless I need to replace my dish but I dont like the idea of being told I have to pay somebody to do something I can do myself.


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## cartrivision (Jul 25, 2007)

joe diamond said:


> Nobody has mentioned that the dish is a parabola (parabolic antenna) that will bounce a signal from whatever angle to a known focus point. The exact position of the LNB is critical because that is the point where all signals will bounce from the dish.
> 
> The reverse example would be a car headlight. The light source is focused on a parabolic mirror and reflects the light out in a straight line which is focused by the headlight lens.
> 
> ...


What I've always wondered is if the multi-LNB dishes are perfectly parabolic, since a perfectly parabolic dish has only one focal point. How do they use one dish to focus signals coming from various satellites at up to an 18 degree offset from center?

If it is a perfectly parabolic dish, I guess that the center LNB is at the parabolic focal point and the others that are at offset angles, while not perfectly focused, are "close enough".


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## dennisj00 (Sep 27, 2007)

This ought to be good!


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## bobnielsen (Jun 29, 2006)

veryoldschool said:


> Besides "dithering about", the term is used to describe finding the edges of the beam and then splitting the distance in half. Ku beams are fairly "pointed" so you can find the peak/center easy, while Ka aren't as much and you get a better idea by using the edges.


Actually the Ka beamwidth is narrower than that for Ku. The dither was adapted as a way to find the center of the 101 Ku beam, which would line it up for Ka, which is less forgiving of a slight error. In the early days, the available meters would only work with Ku (which is still the case with some models) so the alignment had to be done with Ku-only (unless you use the DVR's signal strength screen). Additionally, prior to D10 the only Ka signals were the Spaceway spotbeams and it would have been difficult to align the 5 LNB dishes for Ka in areas where there was not yet LIL coverage.


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## joe diamond (Feb 28, 2007)

cartrivision said:


> What I've always wondered is if the multi-LNB dishes are perfectly parabolic, since a perfectly parabolic dish has only one focal point. How do they use one dish to focus signals coming from various satellites at up to an 18 degree offset from center?
> 
> If it is a perfectly parabolic dish, I guess that the center LNB is at the parabolic focal point and the others that are at offset angles, while not perfectly focused, are "close enough".


Exactly,

The numbers on a graphing calculator make me dizzy. My son the engineer says it is just an old HS phrase to use the term parabola. They can be focused, bent and adjusted and not just for telecom.

The whole thing goes to: "how much is enough?"
There is a wide (enough) service factor to allow field techs to get the thing working..well enough. AND the numbers will NOT stay rock solid after installation even if they are "perfect."

Joe


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## joe diamond (Feb 28, 2007)

gfrang said:


> Mine too as a result of hanging the dish before the cement cured.


Just did one of those!

The house was under comstruction and, as a storm came up the bay, I announced...enough..lets meet again Monday when the weather is better......The site superintendent announced......"the customer wants a few rooms running over the weekend"

The next day we pulled the mast back to plumb, rigged the mast for the week end and dumped more concrete.

All was billed and paid. All three extra trips and all unnecessary resets.

That FREE installation buys you less and less.

Joe


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## joe diamond (Feb 28, 2007)

longrider said:


> What do you mean 'stopped allowing'? Solid Signal still lists the AU9 as in stock. I'm not concerned unless I need to replace my dish but I dont like the idea of being told I have to pay somebody to do something I can do myself.


IF you call to order Directv service.....regardless of your skill or certifications....they will insist on a tech from their Home Service Provider system arriving with the equipment...so they will know where it has been installed.

IF you go out and buy all the equipment for an installation, including a few receivers....When you call to activate the CSR will ask who you are and run a credit check.......if ok they will still not ship you the HD equipment or activate what you have.

You will meet with an HSP tech who will verify the service address.

Joe


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## joe diamond (Feb 28, 2007)

veryoldschool said:


> I think I've read your "poosh" west, and if anything you're "just lucky".
> I read another post sometime back where "you know you're centered" if you use your thumb and press the dish up/down, right/left and see the signal drop. If it doesn't [or goes up] then you're not centered.
> Besides "dithering about", the term is used to describe finding the edges of the beam and then splitting the distance in half. Ku beams are fairly "pointed" so you can find the peak/center easy, while Ka aren't as much and you get a better idea by using the edges.


Actually, I am not just lucky.

I sat on a roof and played with a Birddog for about ten minutes once to find the 103 peak. The 99 was lower but the job has been in for a year or so and still all channels are present.

My issue is not a technical one...The HSP sub contractor & their fulfillment company (DSI) just said now is March 1st and so we are shipping the new Ka/Ku dishes. They did npot ship a meter for the Ka band or offer more money to acquire and use one.

So I "poosh it west a little and play with the tilt. Later I did one for a MASTEC supervisor and asked him how to improve the settings......no adjustment was needed...but I was told I should have used a meter.

It is just a money thing.

Joe


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## joe diamond (Feb 28, 2007)

bobnielsen said:


> Actually the Ka beamwidth is narrower than that for Ku. The dither was adapted as a way to find the center of the 101 Ku beam, which would line it up for Ka, which is less forgiving of a slight error. In the early days, the available meters would only work with Ku (which is still the case with some models) so the alignment had to be done with Ku-only (unless you use the DVR's signal strength screen). Additionally, prior to D10 the only Ka signals were the Spaceway spotbeams and it would have been difficult to align the 5 LNB dishes for Ka in areas where there was not yet LIL coverage.


Bob,
What you say is correct....but what I got was aninstruction to the adjust the Ka/Ku so that when the KA sat at 99 and or 103 (West Longitude) were launched, on, and in position the tuning I did without a meter or signal to tune would not need adjustment.

Idiots!

Some were right in there and some needed a tweak. No money was offered...including no money was offered for fixing jobs other than mine that were done by techs from way the hell out of the area.

I stopped traveling for Directv after they wanted me to go fix one I did way out of my area as a one time favor to a manager. The customer moved the dish as part of a garage construction. The HSP guy lied about the wiring to get paid.

It goes like that,

Joe


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## longrider (Apr 21, 2007)

joe diamond said:


> IF you call to order Dorectv service.....regardless of your skill or certifications....they will insist on a tech from their Home Service Provider system arriving with the equment...so they know where it is installed.
> 
> IF you go out and buy all the equipment for an installation, including a few receivers....When you call to activate the CSR will ask who you are and run a credit check.......if ok they will still not ship you the HD equipment or activate what you have.
> 
> ...


That sounds a little better, it looks like its more a new customer issue. If I change/upgrade it should be no problem? What about if I move?


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## joe diamond (Feb 28, 2007)

longrider said:


> That sounds a little better, it looks like its more a new customer issue. If I change/upgrade it should be no problem? What about if I move?


Yes, it is a new customer issue.

Moving is more of an "on your own" deal. If you move to a new address with NLOS (no line of sight) you could get issues with terminating your contract before the stated duration. Getting them to change local programming can be tricky unless you connect a phone line to verify the location of the new address. The mover's connection will get you some technical help and can be an opportunity for new equipment.

Other than that, you are off and running. One way or another everything after the FREE installation gets paid for by the customer. You can do the work if you want.

Joe


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## BattleScott (Aug 29, 2006)

So in summary:

The mast being out of plumb, assuming that it is not so far out that the dish adjusment mechanisms can not physically compensate, has no effect on the "ability" to acheive maximum signal recepetion. It will only make it more difficult to do so as it will cause what should be "single axis" movements as they relate to the fixed point in the sky (sat x) and makes them "compound" axis movements. 

Is this correct?


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> So in summary:
> 
> The mast being out of plumb, assuming that it is not so far out that the dish adjusment mechanisms can not physically compensate, has no effect on the "ability" to acheive maximum signal recepetion. It will only make it more difficult to do so as it will cause what should be "single axis" movements as they relate to the fixed point in the sky (sat x) and makes them "compound" axis movements.
> 
> Is this correct?


Sounds right.


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## Mike Bertelson (Jan 24, 2007)

BattleScott said:


> So in summary:
> 
> The mast being out of plumb, assuming that it is not so far out that the dish adjusment mechanisms can not physically compensate, has no effect on the "ability" to acheive maximum signal recepetion. It will only make it more difficult to do so as it will cause what should be "single axis" movements as they relate to the fixed point in the sky (sat x) and makes them "compound" axis movements.
> 
> Is this correct?


Exactly. It becomes an iterative process to compensate for the errors induced by the out of plane movements.

I've always wondered (and I've been to lazy to calculate it :grin but it would seem the farther north you are, the larger the induced errors would be.

A question for all you installers; have you run into a situation where it's not possible to plumb the mast?

Mike


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## BattleScott (Aug 29, 2006)

MicroBeta said:


> I've always wondered (and I've been to lazy to calculate it :grin but it would seem the farther north you are, the larger the induced errors would be.


The change in one axis in response to adjusting another would be the same regardless of geography. Why would location be a factor?


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## joe diamond (Feb 28, 2007)

MicroBeta said:


> Exactly.
> 
> A question for all you installers; have you run into a situation where it's not possible to plumb the mast?
> 
> Mike


Nope,

Just situations where it is not possible to plumb the mast without shims and or longer lag bolts on the lower side. Some roof angles exceed the capacity of the mast adjustments. That is often the time to look elsewhere for a dish location.

Joe


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## carl6 (Nov 16, 2005)

BattleScott said:


> The change in one axis in response to adjusting another would be the same regardless of geography. Why would location be a factor?


Hmmm. In thinking about this a little, it would seem to me that geography would affect which of the axis needed more or less adjustment in relation to the others. Therefore what might be a somewhat "easier" compound adjustment in one location could be a somewhat more difficult compound adjustment in a different part of the country due to different look angles being involved (and depending on what direction/dimension the mast was off of perpendicular to start with).


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## cartrivision (Jul 25, 2007)

BattleScott said:


> So in summary:
> 
> The mast being out of plumb, assuming that it is not so far out that the dish adjusment mechanisms can not physically compensate, has no effect on the "ability" to acheive maximum signal recepetion. It will only make it more difficult to do so as it will cause what should be "single axis" movements as they relate to the fixed point in the sky (sat x) and makes them "compound" axis movements.
> 
> Is this correct?


That is not correct unless you are only referring to when you are setting the dish mount with the degree markings in order to do the rough alignment to just find the 101 satellite in the first place. The position of the 101 satellite is measured from known reference points (the horizontal plane and magnetic north) that depends on your location on the spherical surface of the earth so the reference points are different for every different install location, which is why the correct settings are different for every installation location, and which is the ONLY reason that you need a plumb mast.

Past using those known reference points to find the 101 satellite, the orientation of the adjustment axes is completely irrelevant. At that point you are adjusting on a fixed point in space from another fixed point in space. As long as the dish's axis of focus is pointed at the 101 satellite position, the dish can be arbitrarily rotated around the focal axis to any other orientation, and it won't change how the fine tune adjustments work.

We are talking about two fixed points in space. There is no one correct or better adjustment axis orientation that works any differently from another orientation when adjusting a dish that is pointing at one arbitrary fixed point in space from another arbitrary fixed point in space. It doesn't matter if you adjust straight up and down and exactly left and right or if those two perpendicular adjustments are rotated 45 degrees from straight up and down. Up and down are relative, and between two arbitrary points in space, there is no up and down or left and right, so to suggest that the adjustment axes have to be oriented in a specific angle of rotation around the focal axis is beyond absurd. If there is one correct angle, what single reference point is it being measured against in every "correct" DirecTV installation? Multiple plumb poles at different locations on earth can't possibly all be used for a single reference vector for any angular measurement.

This should be a very obvious concept, since every single dish mast is installed in a different and unique orientation. That alone shows that there is no single correct orientation for the mast except when you are depending upon it to set a specific elevation setting that is calculated for (and different for) every mast at every different location on the earth, based in part on the unique horizontal plane for each different location.


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> That is not correct unless you are only referring to when you are setting the dish mount with the degree markings in order to do the rough alignment to just find the 101 satellite in the first place. The position of the 101 satellite is measured from known reference points (the horizontal plane and magnetic north) that depends on your location on the spherical surface of the earth so the reference points are different for every different install location, which is why the correct settings are different for every installation location, and which is the ONLY reason that you need a plumb mast.
> 
> Past using those known reference points to find the 101 satellite, the orientation of the adjustment axes is completely irrelevant. At that point you are adjusting on a fixed point in space from another fixed point in space. As long as the dish's axis of focus is pointed at the 101 satellite position, the dish can be arbitrarily rotated around the focal axis to any other orientation, and it won't change how the fine tune adjustments work.
> 
> ...


It's important get this right, otherwise someone reading all this contradictory info isn't going to know what the right answer is.

By procedure we would set azimuth, elevation, and tilt to aim the dish at the satellite arc; this is the course alignment. Then we fine tune those three settings starting with tilt, then elevation, and lastly azimuth. For those of us who can remember back that far, this is akin to putting the TV on channel 2 and using the fine tuning dial clear up the picture...I'm glad those days are gone. :grin:

As has been discuss in this thread, even by you, if the mast is out of plumb and you move either AZ or EL you also move the other. You've stated more then once that this irrelevant. This doesn't make any sense to me. Why bother having a procedure that goes through the effort to peak EL only to change from its optimal setting (it's fine tuned peak) when we fine tune AZ? The answer is you wouldn't want to. Further, we've all agreed about is that if the mast is plumb then the movement of AZ won't move EL and vice versa.

Why does the procedure call having the mast plumb critical; because, if plumb, you need only fine tune tilt, elevation, and azimuth once. Why this is true relates to the fact that to calculate tilt, elevation, and azimuth you treat any position on the Earth as a point on a sphere and the satellite arc a line on a sphere concentric with the Earth; both of which have a radius which starts at the center of the Earth. Once we realize this then it becomes obvious why having a level mount (by having a plumb mast) will allow movement along AZ, for example, not effect EL with respect to the satellite arc. The most important point to understand is how the dish is moving with respect to the satellite arc we're aiming at. The following posts provide links to all the supporting information and calculations.

http://www.dbstalk.com/showthread.php?p=2243376#post2243376
http://www.dbstalk.com/showthread.php?p=2243624#post2243624

In summary, if the mast isn't plumb and thus the mount not level, then movements of the mount in any direction will interact with the other directions not as it relates to the location of the dish but rather with respect to the satellite arc in orbit. This is why an out of plumb mast becomes an iterative process. If the mast is plumb, you peak tilt, elevation, and azimuth once and you're done. No additional work is necessary. Based on this, BattleScott was absolutely correct.

Of course how far from plumb would be a problem is another question. I suspect you can be off a couple of degrees from plumb and the induced errors in movement will be so small as to be negligible. We could caluclate how big those errors would be but since I know zip point poop about RF field theory I wouldn't have a clue how much error is too much. :grin:

Mike


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## joe diamond (Feb 28, 2007)

cartrivision said:


> That is not correct unless you are only referring to when you are setting the dish mount with the degree markings in order to do the rough alignment to just find the 101 satellite in the first place. The position of the 101 satellite is measured from known reference points (the horizontal plane and magnetic north) that depends on your location on the spherical surface of the earth so the reference points are different for every different install location, which is why the correct settings are different for every installation location, and which is the ONLY reason that you need a plumb mast.
> 
> Past using those known reference points to find the 101 satellite, the orientation of the adjustment axes is completely irrelevant. At that point you are adjusting on a fixed point in space from another fixed point in space. As long as the dish's axis of focus is pointed at the 101 satellite position, the dish can be arbitrarily rotated around the focal axis to any other orientation, and it won't change how the fine tune adjustments work.
> 
> ...


Interesting!

So if you extended every plumb mast infinitely out into space none or maybe a few would actually align with the 101 sat. Therefore each would need a unique set of coordinates to align the dish with that satellite. Since the dish is parabolic in shape it gathers many near misses and focuses them for adequate signal strength to decode the message from the transponders aboard the satellite.

What seems to be the cause of confusion..or I am wrong about this....is that there are five different satellites being used. They are positioned in geosynchronous orbits and produce five independent footprints that are received using the same parabolic dish antenna. If you adjust the dish for a perfect reception from one of the satellites you do so while diminishing the reception from the other four.
And the "perfect" alignment is actually a compromise that gives acceptable service from all five (soon to be three) satellites.

Eh?

Joe


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## BattleScott (Aug 29, 2006)

cartrivision said:


> That is not correct unless you are only referring to when you are setting the dish mount with the degree markings in order to do the rough alignment to just find the 101 satellite in the first place. The position of the 101 satellite is measured from known reference points (the horizontal plane and magnetic north) that depends on your location on the spherical surface of the earth so the reference points are different for every different install location, which is why the correct settings are different for every installation location, and which is the ONLY reason that you need a plumb mast.
> 
> Past using those known reference points to find the 101 satellite, the orientation of the adjustment axes is completely irrelevant. At that point you are adjusting on a fixed point in space from another fixed point in space. As long as the dish's axis of focus is pointed at the 101 satellite position, the dish can be arbitrarily rotated around the focal axis to any other orientation, and it won't change how the fine tune adjustments work.
> 
> ...


No, it is correct at all times.

A plumb mast allows for a single axis adjustment in repsonse to turning that mechanism. Using a very simple example of a single sat requiring no tilt:

Lets assume that a dish needs to be aimed at:
A=101 E=40 
To achieve maximum signal strength.

Lets assume that the dish is currently aligned as
A=103 E=40

Using a plumb installation:

We adjust the azimuth -2 degrees and we get perfect aligment:
A=101 E=40 
Project done.

Using a non-plumb installation:
We adjust the azimuth -2 degrees to acheive the A=101 desired setting. However, since the mast is leaning slightly southward (out of plumb), we have now introduced a certain error in the elevation setting. 
A=101 E=39.3

The elevation setting must now be corrected to bring the dish back to the optimal setting. So we adjust the elevation +0.7 degrees. However, since the mast is also leaning slightly westward, we introduce a small error in the azimuth setting. 
A=100.5 E=40

So we adjust the azimuth +0.5 degrees to acheive the A=101 desired setting. However, since the mast is leaning slightly southward (out of plumb), we have now introduced a certain error in the elevation setting. 
A=101 E=39.8

and so on...

In all cases, regardless of geographic location, a plumb mast is the only way to allow for single-axis adjustments of the dish.


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## Mike Bertelson (Jan 24, 2007)

joe diamond said:


> Interesting!
> 
> So if you extended every plumb mast infinitely out into space none or maybe a few would actually align with the 101 sat. Therefore each would need a unique set of coordinates to align the dish with that satellite. Since the dish is parabolic in shape it gathers many near misses and focuses them for adequate signal strength to decode the message from the transponders aboard the satellite.
> 
> ...


Actually we need to think of it as the mount being level. Having a plumb mast gets you there. This makes the movements of the mount orthogonal to a plane that's effectively tangent to the Earth. This keeps movements of the mount/dish independent of each other with respect to the location of the satellites.

As for the spread of the satellite arc, that's what tilt is about. I've talked to someone about the signals and it has something to do with circular polarization. I don't know much about RF field theory but as it was explained to me, as long as tilt, elevation, and azimuth are correct you should get strong signal from all the satellites. I buy this because when I can look my signal strengths I see 80s, 90s, and a few 100s. Since these signal strengths (in my case) are pretty much the same on all satellites (on the applicable transponders), it seems polarization on a properly aimed dish is the other part of the puzzle that make viewing multiple satellites work. However, I'm an engineer who specializes in computational mechanics so I don't have a clue one about RF field theory. The Smith Chart is a bunch of gibberish as far as I'm concerned. :grin:

Mike


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> No, it is correct at all times.
> 
> A plumb mast allows for a single axis adjustment in repsonse to turning that mechanism. Using a very simple example of a single sat requiring no tilt:
> 
> ...


While your theory is correct, your scale/magnitude isn't.
A mast leaning 45 degrees out of plumb, would have a one to one "error" for changes in AZ affecting EL.
Since this is trig, the errors in the 1-5 degrees out of plumb would be so small as to be "almost negligible" to the focus of the dishes we're using.


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## veryoldschool (Dec 10, 2006)

joe diamond said:


> What seems to be the cause of confusion..or I am wrong about this....is that there are five different satellites being used. They are positioned in geosynchronous orbits and produce five independent footprints that are received using the same parabolic dish antenna. If you adjust the dish for a perfect reception from one of the satellites you do so while diminishing the reception from the other four.
> And the "perfect" alignment is actually a compromise that gives acceptable service from all five (soon to be three) satellites.
> 
> Eh?
> ...


If we were using a [deep space] 30 meter dish, this last part would be correct, but since we're not using a "prefect parabolic dish", and instead a "parabolic oval", we're not "detuning" one SAT to gain the others.


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## veryoldschool (Dec 10, 2006)

This thread has gone on so long that I'm almost about to go out and change my mast so it is horizontal [pointing east], realign my dish, time how long it takes, and then post screen shots of my levels from each SAT and how the dish looks.
Even after doing this, I'm sure there will still be those that would call this fake or I used photoshop, so I'm guessing "the Myth" will continue. :nono:


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## joe diamond (Feb 28, 2007)

veryoldschool said:


> If we were using a [deep space] 30 meter dish, this last part would be correct, but since we're not using a "prefect parabolic dish", and instead a "parabolic oval", we're not "detuning" one SAT to gain the others.


Then could it be said that there is a tuned position for the dish that receives all sat signals better than all others? For example, I have been tuning the 101 and 119 with the expectation that the 99 & 103 have been positioned to be aligned when the 101 & 119 are peaked. I notice I can raise the numbers on the 103c here on the east coast but the 101 goes down a little.

I gotta wonder if this concept is not contained in a training manual somewhere?

Joe


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## veryoldschool (Dec 10, 2006)

joe diamond said:


> Then could it be said that there is a tuned position for the dish that receives all sat signals better than all others? For example, I have been tuning the 101 and 119 with the expectation that the 99 & 103 have been positioned to be aligned when the 101 & 119 are peaked. I notice I can raise the numbers on the 103c here on the east coast but the 101 goes down a little.
> 
> Joe


I use the analogy of a silver dollar verse a quarter. "Theoretically" the SATs are all perfectly positioned, such that the wider Ku beam has the narrower Ka beam both centered on the exact spot. Using a bull's eye target: the Ku would cover the 10 ring while the Ka would cover only the 5 ring.
You can have Ku levels good, but have Ka centered "on" the 5 ring, instead of centered in the middle.
I've never had the 101/110/119 drop as I fine tune either 99/103. This has been with a sample of two [AT-9 & AU-9] dishes. The more dishes that get installed the [few to date] more posts we're getting about damaged [bent] reflectors causing problems.


> I gotta wonder if this concept is not contained in a training manual somewhere?


 I'd say that most of this thread goes way beyond the the level of the training manual.


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## gfrang (Aug 30, 2007)

Ok here is my take on this subject. With the mast being plumb you are moving the alignment in 2 axes, the x being the al the y being the el and also there is a third the third z being the distance between the dish and the sats which you don't wan't to move unless you have nothing else to do. 

With the dish being plumb the x and y move interdependent of one another. If the mast isn't plumb there is another factor that is the plane, if it shifts whit the mast the el and az can no longer move independently meaning one will change the other. 

If the mast is plumb then the plane will lie perpendicular whit the z and make alignment a piece of cake. 

Sorry i just woke up and didn't have my coffee yet i just grab a cup and go back to sleep.


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> While your theory is correct, your scale/magnitude isn't.
> A mast leaning 45 degrees out of plumb, would have a one to one "error" for changes in AZ affecting EL.
> Since this is trig, the errors in the 1-5 degrees out of plumb would be so small as to be "almost negligible" to the focus of the dishes we're using.


So if it's "almost negligible" then a plumb mast is still desirable when discussing dish alignment. If it is "negligible" then a plumb mast is of no benefit.

Assuming a mast error of 5 degrees southward. Every 1 degree of azimuth adjustment will generate slightly more that 0.1 degree of elevation error, correct?

It seems that we should be able to determine a tolerance in plumb error of the mast that would be acceptable. In other words, assuming the standard dithering method of alignment, at what error in plumb would the change in one axis due to the adjustment of another be enough to begin to adversely affect the readings while sweeping the dish?


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## Mike Bertelson (Jan 24, 2007)

gfrang said:


> Ok here is my take on this subject. With the mast being plumb you are moving the alignment in 2 axes, the x being the al the y being the el and also there is a third the third z being the distance between the dish and the sats which you don't wan't to move unless you have nothing else to do.
> 
> With the dish being plumb the x and y move interdependent of one another. If the mast isn't plumb there is another factor that is the plane, if it shifts whit the mast the al and ez can no longer move independently meaning one will change the other.
> 
> ...


Yes. You have it absolutely correct. Just be clear, it's that x & y (AZ & EL) need to move independent of the line of satellites. I know you understand this but I just wanted to make sure it's clear to someone else reading our posts. It's an important distinction that some may not be accounting for.

IIRC(and I hope I do remember correctly), the dish has to be within 0.1° when peaking the 101°/119° satellites. If the movements aren't independent of each other with respect to the satellite arc it's virtually impossible to get there. The Ka band is so narrow that if you aren't ±0.1°, you can wind up with interference from adjacent satellites slots. While you may be able to get "close enough", when coupled bad weather with that interference you could have a problem. A tech is more qualified to handle that discussion then I am. I sometimes wonder how many call backs are due to slight alignment issues. :grin:

Mike


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## Mike Bertelson (Jan 24, 2007)

BattleScott said:


> So if it's "almost negligible" then a plumb mast is still desirable when discussing dish alignment. If it is "negligible" then a plumb mast is of no benefit.
> 
> Assuming a mast error of 5 degrees southward. Every 1 degree of azimuth adjustment will generate slightly more that 0.1 degree of elevation error, correct?
> 
> It seems that we should be able to determine a tolerance in plumb error of the mast that would be acceptable. In other words, assuming the standard dithering method of alignment, at what error in plumb would the change in one axis due to the adjustment of another be enough to begin to adversely affect the readings while sweeping the dish?


I'm out of my area with this but since the Ka band is so narrow and we have a potential of satellites with in two degrees on either side, it probably wouldn't take very much to cause problems.

Interesting conundrum! The distances are so huge, the Ka band is so narrow and the orbital slots so close that I think we're probably talking about a very small amount of error. Heck using that inane little level in the top of the mast is enough to give you a ± tolerance to be a problem. Then couple that with not plumbing it all and I think it's a call back waiting to happen.

I think that's why DirecTV is so strict on plumbing the mast and properly using the dithering procedure. They need the aim to be as tight as possible to minimize tech support and call backs. My 2¢ FWIW. :grin:

Mike


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> So if it's "almost negligible" then a plumb mast is still desirable when discussing dish alignment. If it is "negligible" then a plumb mast is of no benefit.
> 
> Assuming a mast error of 5 degrees southward. Every 1 degree of azimuth adjustment will generate slightly more that 0.1 degree of elevation error, correct?
> 
> It seems that we should be able to determine a tolerance in plumb error of the mast that would be acceptable. In other words, assuming the standard dithering method of alignment, at what error in plumb would the change in one axis due to the adjustment of another be enough to begin to adversely affect the readings while sweeping the dish?


You're making my head hurt. :lol:
Let's use the EL adjustment on a mast 5 degrees east/west. One degree of EL would be the tangent and the "real change" of EL would be sine of 85 degrees [0.99619] and the "change of AZ" would be the cosine [0.087155].
So from the "base EL" you're going to be 0.4% off [which in my location would be 0.164 degrees] and to correct this, the AZ would change about .01 degrees.
Now if I haven't screwed up here, this would be truly "negligible".


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## veryoldschool (Dec 10, 2006)

MicroBeta said:


> They need the aim to be as tight as possible to minimize tech support and call backs. My 2¢ FWIW. :grin:
> 
> Mike


I just "dither about" to get this. :lol:


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> It seems that we should be able to determine a tolerance in plumb error of the mast that would be acceptable. In other words, assuming the standard dithering method of alignment, at what error in plumb would the change in one axis due to the adjustment of another be enough to begin to adversely affect the readings while sweeping the dish?


If one understands both what the adjustments of the dish do "and" trigonometry, one "could take this" to the extremes of the mast being horizontal and "know" that as it moved past the 45 degree mark that the AZ would be changed more by the EL adjustment and EL would change the AZ more.
"On the other hand": if one doesn't understand trig, and only knows to adjust the basic settings, "one should" start with a perfectly plumb mast.


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## Mike Bertelson (Jan 24, 2007)

veryoldschool said:


> I just "dither about" to get this. :lol:


Yeah I know. It's rather awkwardly worded but you get the point. :grin:

Mike


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> If one understands both what the adjustments of the dish do "and" trigonometry, one "could take this" to the extremes of the mast being horizontal and "know" that as it moved past the 45 degree mark that the AZ would be changed more by the EL adjustment and EL would change the AZ more.
> "On the other hand": if one doesn't understand trig, and only knows to adjust the basic settings, "one should" start with a perfectly plumb mast.


This is kind of my point... kind of. 
For the average DIYer, obviously you would want to achieve maximum "plumbness". But in real world mounting scenarios where getting the mast perfectly plumb is not realistic, is there a window (+/- 10 degrees it sounds like is not out of the question) where you will still be able to follow the standard alignment procedures and achieve the same results as starting with a plumb mast?


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> This is kind of my point... kind of.
> For the average DIYer, obviously you would want to achieve maximum "plumbness". But in real world mounting scenarios where getting the mast perfectly plumb is not realistic, is there a window (+/- 10 degrees it sounds like is not out of the question) where you will still be able to follow the standard alignment procedures and achieve the same results as starting with a plumb mast?


"I hope" all along, I've been saying "plumb" is a good place to start and it will make the job easier and quicker.
"I think" if the mast looks anywhere close, it will work fine.
"My peeve" has been with "exactly plumb" posts, where I'm envisioning laser levels and surveyor's equipment being needed to have these set.
I'd say spending the time tweaking the dish would be more important, than "how plumb" the mast is.


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> But in real world mounting scenarios where getting the mast perfectly plumb is not realistic...


I can see some situations where the dish may not be able to be aligned with the mast plumb.
One could be when mounted on the side of the house and the reflector simply doesn't have enough clearance. I would lean the mast out to 45 degrees if it would then clear, before I'd extend the mast. With the braces, it would be as stable, and the alignment wouldn't that that much longer, but yes it would take several "rechecks/adjustments" in fine tuning.
Another place could be on a roof where the framing would be more important to screw into than having the mast plumb with it's single [axis] adjustment.
I'm sure these two aren't the only conditions, and in each case the three adjustments on the dish will work to correctly align the dish for all SATs.


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> "I hope" all along, I've been saying "plumb" is a good place to start and it will make the job easier and quicker.
> "I think" if the mast looks anywhere close, it will work fine.
> "My peeve" has been with "exactly plumb" posts, where I'm envisioning laser levels and surveyor's equipment being needed to have these set.
> I'd say spending the time tweaking the dish would be more important, than "how plumb" the mast is.


First, I just want to be clear that I am not "arguing" with you in any way. I am trying to clear this in my own mind as my particular mount is ever so slightly out of plumb and I have always wondered how much "true" effect it has on the overall adjustment process.

I'm actually kind of confused as to what you are saying. Initially you agreed with my summary that a plumb mast would be desirable in order to align the dish using the standard processes. It now seems like you are saying that plumbness is really not important and that the errors in plumb would need to be quite large before they begin to affect the alignment process.

In your math example in post #116, it would seem that errors in plumb of 5 to even 10 degrees (possibly more) would be inconsequential in terms of using the dithering procedure for aligning the dish once it is installed.

If this is true, then the initial contention of the thread is true and eyeballing the mast (assuming a reasonably calibrated eyeball) at installation is all that is needed. 
In addition, it would seem that spending extra time or in worst case scenarios, relocating to a new mounting location in order to achieve "plumbness" would be wasted effort as the results are going to be the same using the standard aligment process as they would if the mast were plumb.

Most importantly, it would seem that the slight error in plumb of *MY* installation is no cause for concern...


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## joe diamond (Feb 28, 2007)

Guys,

Many techs, including myself, have done this installation in the dark while rain is falling (or snow). The first few hundred can be daunting but after awhile it falls into a routine; hand-eye-satellite memory.

THEN, on a sunny day, a dude from the HSP comes along with his nice blue shirt and $500.00 meter to looks at the results.

I have enjoyed the conversation and learned from the responses of the participants.

Joe


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> First, I just want to be clear that I am not "arguing" with you in any way. I am trying to clear this in my own mind as my particular mount is ever so slightly out of plumb and I have always wondered how much "true" effect it has on the overall adjustment process.
> 
> I'm actually kind of confused as to what you are saying. Initially you agreed with my summary that a plumb mast would be desirable in order to align the dish using the standard processes. It now seems like you are saying that plumbness is really not important and that the errors in plumb would need to be quite large before they begin to affect the alignment process.
> 
> ...


I haven't taken your posts as an argument. "A challenge" to how well I can explain my point perhaps, but one that I will be glad to take.
"The worst case" with a mast out of plumb is needing to go back and readjust an earlier adjustment after doing another axis. You might need to do this many times, before all axises are centered. In all cases, each adjustment will move across the center of the beam, though maybe not the two axis center [fine tuning adjusters]. This means repeating this on each axis until both axises have been tweaked to cross the center. Tilt has no fine tuning, so this would take some finesse, but it is only rotating the dish/LNBs on the center and the fine tuning adjusters will still tweak two axises across the center.

"As for your second part"
It's not that I've "changed" anything. "My point is" if the mast is plumb, I may need to only do each adjustment once. As it gets to the extreme [out of plumb, say 45 degrees], adjusting will take longer as each adjustment will need to be rechecked/re-tweaked "over and over" as the dish comes into the center of the bull's eye.


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## veryoldschool (Dec 10, 2006)

joe diamond said:


> Guys,
> 
> Many techs, including myself, have done this installation in the dark while rain is falling (or snow). The first few hundred can be daunting but after awhile it falls into a routine; hand-eye-satellite memory.
> 
> ...


Joe it should be clear to everyone here that you have a "feel" for how to do this. Anybody that has done it half as many times as you, should have this.
"As for the blue shirts and fancy meters": Are they checking for "optimum" levels or simply meeting "desired" levels?
This first is what takes the time, while the second is "good enough".


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## Shades228 (Mar 18, 2008)

There's a lot of good information in this thread. Perhaps it might be better served in the installation forum though as people would look there for this type of post first.


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## veryoldschool (Dec 10, 2006)

This will fade from page one soon enough on either forum.


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## Shades228 (Mar 18, 2008)

veryoldschool said:


> This will fade from page one soon enough on either forum.


I agree I was thinking about the searching later on.


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## RobertE (Jun 10, 2006)

veryoldschool said:


> This will fade from page one soon enough on either forum.


Not soon enough. :lol:


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## veryoldschool (Dec 10, 2006)

bobnielsen said:


> Actually the Ka beamwidth is narrower than that for Ku. The dither was adapted as a way to find the center of the 101 Ku beam, which would line it up for Ka, which is less forgiving of a slight error. In the early days, the available meters would only work with Ku (which is still the case with some models) so the alignment had to be done with Ku-only (unless you use the DVR's signal strength screen). Additionally, prior to D10 the only Ka signals were the Spaceway spotbeams and it would have been difficult to align the 5 LNB dishes for Ka in areas where there was not yet LIL coverage.


[side note: this post had seven "strange characters" in it that I've delete, they were a square with four dots FWIW]

For all those that have meters that can read the Ka SATs and thought their days of dithering were long gone... it's not so with the SWMLNB.
Since the SWMLNB has 30 dB of AGC, without dithering they isn't a way to know where the center is. You could be reading levels that look "normal" to you [compared to non SWM LNB outputs] and still be close to the edge of the beam. By dithering to the same drop in output, the AGC is taken out of the measurement when it maxes out. 
One of the pluses of a SWM is this gain and that it reduces the on-set of rain fade. I've had some pretty nasty storms here and only lost signal for a few mins. Before the SWM, I've lost signals for a good 15 mins or more. It isn't the "cure all", but the AGC gain does help.


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> I haven't taken your posts as an argument. "A challenge" to how well I can explain my point perhaps, but one that I will be glad to take.
> "The worst case" with a mast out of plumb is needing to go back and readjust an earlier adjustment after doing another axis. You might need to do this many times, before all axises are centered. In all cases, each adjustment will move across the center of the beam, though maybe not the two axis center [fine tuning adjusters]. This means repeating this on each axis until both axises have been tweaked to cross the center. Tilt has no fine tuning, so this would take some finesse, but it is only rotating the dish/LNBs on the center and the fine tuning adjusters will still tweak two axises across the center.
> 
> "As for your second part"
> It's not that I've "changed" anything. "My point is" if the mast is plumb, I may need to only do each adjustment once. As it gets to the extreme [out of plumb, say 45 degrees], adjusting will take longer as each adjustment will need to be rechecked/re-tweaked "over and over" as the dish comes into the center of the bull's eye.


I still am not clear as to whether or not the aligment process requires re-adjusting one axis in response to changing another if the mast is only out of plumb by a small amount. And if so, at what amount of plumb error does this condition begin. Some here have stated that the amount of error required is very small and others have maintained it is very large. Still others have charged that any error in plumb is not relevant as it has no bearing on the adjustment axis of the dish.

So, in the interests of some poor slob who happens across this thread some time in the future, can anyone provide a numerical answer to the following question:

At what degree of plumb error does the error induced in one axis by the adjustment of another pass the "negligible" point and begin to require the operator to have to go back and "re-peak" a previously peaked setting to achieve maximum signal strength?


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> I still am not clear as to whether or not the aligment process requires re-adjusting one axis in response to changing another if the mast is only out of plumb by a small amount. And if so, at what amount of plumb error does this condition begin. Some here have stated that the amount of error required is very small and others have maintained it is very large. Still others have charged that any error in plumb is not relevant as it has no bearing on the adjustment axis of the dish.
> 
> So, in the interests of some poor slob who happens across this thread some time in the future, can anyone provide a numerical answer to the following question:
> 
> At what degree of plumb error does the error induced in one axis by the adjustment of another pass the "negligible" point and begin to require the operator to have to go back and "re-peak" a previously peaked setting to achieve maximum signal strength?


Since there are many variables here [how far north, east/west, and out of plumb is "some direction"], let's start with a base point:
You set the EL & Tilt to the "basic settings for your location" and then swing the dish on the mast [AZ] until you have a signal maxed out.
Now you want to fine tune the dish. The dish has to be within about 1 degree.
"So" without going through every EL & out of plumb angle that one might have, "I'll say" 30 degrees out of plumb, because: in a "worst case" changing one axis, one degree, would only change the other axis 0.5 degree.
The "simple fact" is that after adjusting one axis and then the other, if your levels aren't as high as you'd like, you should re-check the other axis. "And then" make sure all the SAT levels are still good.


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## bobnielsen (Jun 29, 2006)

veryoldschool said:


> I haven't taken your posts as an argument. "A challenge" to how well I can explain my point perhaps, but one that I will be glad to take.
> "The worst case" with a mast out of plumb is needing to go back and readjust an earlier adjustment after doing another axis. You might need to do this many times, before all axises are centered. In all cases, each adjustment will move across the center of the beam, though maybe not the two axis center [fine tuning adjusters]. This means repeating this on each axis until both axises have been tweaked to cross the center. Tilt has no fine tuning, so this would take some finesse, but it is only rotating the dish/LNBs on the center and the fine tuning adjusters will still tweak two axises across the center.
> 
> "As for your second part"
> It's not that I've "changed" anything. "My point is" if the mast is plumb, I may need to only do each adjustment once. As it gets to the extreme [out of plumb, say 45 degrees], adjusting will take longer as each adjustment will need to be rechecked/re-tweaked "over and over" as the dish comes into the center of the bull's eye.


Since the azimuth and elevation adjustment planes are orthogonal the adjustments shouldn't interact, even though they don't line up with the horizontal and vertical planes. The elevation and tilt markings on the dish will be off and it will take a bit longer to get close enough to use a meter but dithering shouldn't be affected.


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## bobnielsen (Jun 29, 2006)

veryoldschool said:


> [side note: this post had seven "strange characters" in it that I've delete, they were a square with four dots FWIW]


I'm not seeing that on my posts, but sometimes a word or two will have a red underline, indicating a spell-check error. I suspect that is the same thing but my browser (Safari) isn't displaying the strange characters. If I back-space and retype the word, the underline goes away. I'll check that post with a different browser and see what shows up. Strange....

Edit: Firefox shows the strange characters. I suspect I must have hit two keys at once or ??


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## joe diamond (Feb 28, 2007)

veryoldschool said:


> Joe it should be clear to everyone here that you have a "feel" for how to do this. Anybody that has done it half as many times as you, should have this.
> "As for the blue shirts and fancy meters": Are they checking for "optimum" levels or simply meeting "desired" levels?
> This first is what takes the time, while the second is "good enough".


V. Old School,
I guess I was alluding to a practice that is outside quality control. Installers get pushed to complete jobs under many different conditions. Regardless of those conditions, a list of specifications still exists. The money stays the same regardless of the day, time or conditions but the person doing the QC (quality Control) often does not know or care about anything but what he sees on a clear day.

I am unaware that actual signal levels are checked outside of a customer call. I get the impression that any check will be for unimportant deviations to pay the wages of the inspector through tech back charges..

Joe


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## veryoldschool (Dec 10, 2006)

joe diamond said:


> V. Old School,
> I guess I was alluding to a practice that is outside quality control. Installers get pushed to complete jobs under many different conditions. Regardless of those conditions, a list of specifications still exists. The money stays the same regardless of the day, time or conditions but the person doing the QC (quality Control) often does not know or care about anything but what he sees on a clear day.
> 
> I am unaware that actual signal levels are checked outside of a customer call. I get the impression that any check will be for unimportant deviations to pay the wages of the inspector through tech back charges..
> ...


You do know "the game" better than most. The theoretical BS in these threads have so little to do with "doing the job for a living". Since most installers are paid by the job, and not by the hour, "If I were them", I'd do as good a jobs as I could "as fast as I could". There simply isn't any money in "gold plating" the job.
"I'd guess" QC [QA] inspectors are just like a home inspector. They must find "something" to justify their existence, but with an installer it could take money out of their pocket.


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## joe diamond (Feb 28, 2007)

veryoldschool said:


> You do know "the game" better than most. The theoretical BS in these threads have so little to do with "doing the job for a living". Since most installers are paid by the job, and not by the hour, "If I were them", I'd do as good a jobs as I could "as fast as I could". There simply isn't any money in "gold plating" the job.
> "I'd guess" QC [QA] inspectors are just like a home inspector. They must find "something" to justify their existence, but with an installer it could take money out of their pocket.


Yup,

Joe


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## Mike Bertelson (Jan 24, 2007)

bobnielsen said:


> Since the azimuth and elevation adjustment planes are orthogonal the adjustments shouldn't interact, even though they don't line up with the horizontal and vertical planes. The elevation and tilt markings on the dish will be off and it will take a bit longer to get close enough to use a meter but dithering shouldn't be affected.


I guess interact is a poor choice of words. It's really that with respect to the satellite arc, moving one with will cause a repositioning of the other. While the movements would be orthogonal to each other, the plane on which on which the movements take place aren't orthogonal in a spherical frame of reference. A plumb mast takes care of that.

You can prove the concept with a laser pointer if you care to take a bunch of careful measurements to do a mock up.

Mike


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## BattleScott (Aug 29, 2006)

So in conclusion (i hope) :

While a perfectly plumb mast is required for true "single-axis" adjustments, the error induced by the mast being slightly out of plumb (+/- 10 degrees in any/all directions) is negligible in terms of practical dish alignment for the DIYer, and would not require any additional time or steps to ahcieve maximum signal strength readings.

Is this correct?


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> Is this correct?


I think the math proves this.


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> I think the math proves this.


Great, now I can finally sleep!


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## Mike Bertelson (Jan 24, 2007)

BattleScott said:


> So in conclusion (i hope) :
> 
> While a perfectly plumb mast is required for true "single-axis" adjustments, the error induced by the mast being slightly out of plumb (+/- 10 degrees in any/all directions) is negligible in terms of practical dish alignment for the DIYer, and would not require any additional time or steps to ahcieve maximum signal strength readings.
> 
> Is this correct?


I'm not a satellite tech or an installer so take the following with a grain of salt. However, I think ±10° is much too large an offset. I might not have thought so a couple of days ago but I recently went back and reviewed some theory stuff I had from a couple of years ago.

According to what I've read, the Ka band is so narrow that if you don't peak the dish with the dither process it's impossible to get it right due to the accuracy of the meters. Now take into account that there will be a potential of satellites with orbital slots having only 2° of separation (97°, 99°, 101°, 103°, 105°, etc), according to DirecTV techs, unless the dish is plumb (mount level) and you use the whole dithering process it's impossible to get it right. It seems that unless its spot on there will be interference between orbital slots and that coupled with; say bad weather, you're looking at problems with audio/video.

Honestly, I don't know enough about RF theory to say how true this is but it does bear thought. I remember seeing a video where they put a laser pointer on a dish aimed at a grid. The DirecTV techs aimed the dish and aligned the pointer to the grid. It was about most of the common problems with dish alignment using dithering. At the end of the video they brought out a woman who worked in the office. She had never touched a dish before in her life. They gave her a five minute discussion about the meter and dithering. In less then two minuets she had the dish spot on. If the mount wasn't level she would never had been able to do it in that amount of time.

I can't prove ±10° is too much but based on what I do know it's my opinion it is (I have any idea what too much actually would be). Also, I'll bet that how much is too much will also depend on the direction it's off.

Yeah, I know. This doesn't help answer your question, sorry. :shrug:

I'm not sure there's anyone here who can give you a definitive answer either way. 

I do have a pet peeve though and I'm not just trying to be a pita but there's no such thing as perfectly plumb. It's either plumb or it isn't...he says knowing he's gonna hear about it. :grin:

Mike


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## gfrang (Aug 30, 2007)

I to feel that ±10° is way to much,the extra time you spend plumbing it up you will get it all back when you align.


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## joe diamond (Feb 28, 2007)

Of course....it all depends on whether or not the dish is plumb AND grounded. An out of column dish that is also not grounded has little chance of ever . . .

Sorry,

Joe


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> Why does the procedure call having the mast plumb critical; because, if plumb, you need only fine tune tilt, elevation, and azimuth once. Why this is true relates to the fact that to calculate tilt, elevation, and azimuth you treat any position on the Earth as a point on a sphere and the satellite arc a line on a sphere concentric with the Earth; both of which have a radius which starts at the center of the Earth. Once we realize this then it becomes obvious why having a level mount (by having a plumb mast) will allow movement along AZ, for example, not effect EL with respect to the satellite arc. The most important point to understand is how the dish is moving with respect to the satellite arc we're aiming at.


Why do you keep repeating this illogical nonsense???? If it was important for the dish alignment axes to move in a certain direction with respect to the arc of the satellites, then every mount on every mast would have be aligned to the same axes. *BUT THEY AREN'T... THEY ARE ALL ALIGNED TO DIFFERENT AXES. PLUMB IS A DIFFERENT VECTOR WITH A DIFFERENT ANGULAR RELATIONSHIP TO THE ARC OF SATELLITES FROM EVERY DIFFERENT LOCATION ON EARTH.* Therefore, the whole supposition of your argument COMPLETELY FAILS a simple logic test. You claim that a uniform set of adjustment axes are important while failing to recognize or explain the fact that every single dish installation has a DIFFERENT set of axes (in relation to the satellite arc) on which those adjustments happen.



> The following posts provide links to all the supporting information and calculations.
> 
> http://www.dbstalk.com/showthread.php?p=2243376#post2243376
> http://www.dbstalk.com/showthread.php?p=2243624#post2243624


No they don't. It's just more of the same illogical nonsense that you keep repeating, with references to some actual (but irrelevant) facts that in no way explain away the SIMPLE ERROR IN YOUR LOGIC that I keep pointing out and you keep failing to address and explain.



> In summary, if the mast isn't plumb and thus the mount not level, then movements of the mount in any direction will interact with the other directions not as it relates to the location of the dish but rather with respect to the satellite arc in orbit. This is why an out of plumb mast becomes an iterative process. If the mast is plumb, you peak tilt, elevation, and azimuth once and you're done. No additional work is necessary. Based on this, BattleScott was absolutely correct.


*AGAIN....* you fail to explain how if the adjustment axes must relate to the arc of the satellites in just the right way, how having a plumb mast does that, when *SIMPLE LOGIC* dictates that the axes of a plumb mast will have a *DIFFERENT* relationship to the axis of the arc of satellites from every different location on earth.



> Of course how far from plumb would be a problem is another question. I suspect you can be off a couple of degrees from plumb and the induced errors in movement will be so small as to be negligible. We could caluclate how big those errors would be but since I know zip point poop about RF field theory I wouldn't have a clue how much error is too much. :grin:


More completely unmitigated hand-waving nonsense. A plumb pole on an arbitrary location on earth can be pointing in *ABSOLUTELY ANY DIRECTION* depending on the location on the sphere that has an infinite number of vectors that are all "plumb" to the sphere, so every single plumb pole installation has a different set of adjustment axes than all of the others... yet you still claim that there is a "correct" orientation of the adjustment axes in relation to the arc of the satellites. Again your supposition fails the test of simple logic. The position of that arc of satellites in space is completely static in relationship to any position on earth, so to have and maintain one "correct" set of axes of adjustment with respect to that stationary arc, every mast would need to be pointing in the same direction... *NOT PLUMB.... PLUMB MAKES EVERY MAST POINT IN A DIFFERENT ANGULAR DIRECTION WITH RESPECT TO THAT SATELLITE ARC, AND WITH RESPECT TO ANY OTHER FIXED POSITION ARC OR LINE OR VECTOR ETC. ETC. ETC.*

How much simpler can I explain the fundamental and glaring logical flaw in your argument????????


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## cartrivision (Jul 25, 2007)

veryoldschool said:


> BattleScott said:
> 
> 
> > No, it is correct at all times.
> ...


Actually, BattleScott's whole "explanation" completely ignores the that fact that the AZ and EL adjustments are relative to every unique vector of every plumb mast, so picking an arbitrary axes of reference for AZ and EL and saying that alignment to some other axes of reference will make the AZ or EL adjustments move on compound axes as measured against the first reference vectors, is true but completely irrelevant, because there is nothing magical or correct or true or anything else about the first vectors of reference, since EVERY such point of reference has an uniquely different angular relationship to the fixed positions of the satellites .... so which one is the "correct" one that doesn't cause movement on compound axes when changing the AZ and EL adjustments on the dish mount?

As the above simple statements of logic demonstrate, there is no one "correct" vector for the mast, because the vectors of adjustment are relative to an arbitrary set of axes, and no two plumb masts have an equivalent angular relationship to the arc of satellites in the sky.... making no single angular relationship to the arc of satellites in the sky either correct or incorrect.

In simple terms.... being out of plumb *only* means that the AZ and EL adjustments move on compound axes in relation to an irrelevant (and somewhat arbitrary) set of reference vectors that point in a different direction for every install location as measured in relation to the fixed positions of the satellites.


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> gfrang said:
> 
> 
> > Ok here is my take on this subject. With the mast being plumb you are moving the alignment in 2 axes, the x being the al the y being the el and also there is a third the third z being the distance between the dish and the sats which you don't wan't to move unless you have nothing else to do.
> ...


No he is not absolutely correct, since each single axis of adjustment is completely relative to the unique orientation of the dish mount and no two plumb mast at different locations will have an equivalent angular relationship to the arc of satellites.



> IIRC(and I hope I do remember correctly), the dish has to be within 0.1° when peaking the 101°/119° satellites. If the movements aren't independent of each other with respect to the satellite arc it's virtually impossible to get there.


Nonsense, since the vectors that you are choosing as a reference point from which to measure "independent" (or non-compound) movement are irrelevant and have no meaningful angular relationship to the positions of the satellite arc, in addition to being different for every dish location.

If there is a single "correct" angular relationship to the fixed position of the satellite arc for the axes of movement of the dish mount adjustments, what is it? Then... how can multiple plumb masts each with a different vector of orientation still both have the same "correct" angular relationship to that arc of satellites?

Your inability to answer those two very simple questions demonstrates the complete fallacy of your wildly illogical and incorrect statements.


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> No he is not absolutely correct, since each single axis of adjustment is completely relative to the unique orientation of the dish mount and no two plumb mast at different locations will have an equivalent angular relationship to the arc of satellites.


It is correct. You just don't understand how a spherical coordinate system applies. 


> > IIRC(and I hope I do remember correctly), the dish has to be within 0.1° when peaking the 101°/119° satellites. If the movements aren't independent of each other with respect to the satellite arc it's virtually impossible to get there.
> 
> 
> Nonsense, since the vectors that you are choosing as a reference point from which to measure "independent" (or non-compound) movement are irrelevant and have no meaningful angular relationship to the positions of the satellite arc, in addition to being different for every dish location.


BTW, this information comes directly from a DirecTV training video on the dithering process so if you don't believe it then take it up with them. You really need to stop calling something nonsense if you aren't going to prove why it's nonsense. You can say what you want but if you can't show support for it then it's nothing but baseless garbage.



> If there is a single "correct" angular relationship to the fixed position of the satellite arc for the axes of movement of the dish mount adjustments, what is it? Then... how can multiple plumb masts each with a different vector of orientation still both have the same "correct" angular relationship to that arc of satellites?


Yes there is a correct angular relationship. It is the angle between the radius of the satellite arc and the radius of the surface of the Earth; both of which go back to the center of the Earth. This angular relationship puts the mount level on a plane tangential to that radius. You would need to understand spherical coordinate systems for this to make sense...but then you wouldn't need to ask the question in the first place.



> Your inability to answer those two very simple questions demonstrates the complete fallacy of your wildly illogical and incorrect statements.


 I have answered those questions. However, since you don't understand how a spherical coordinate system applies, you are unable to understand my answers.


cartrivision said:


> <snip>
> How much simpler can I explain the fundamental and glaring logical flaw in your argument????????


The problem is your explanation, no matter how often you repeat it, it wrong. You keep saying the same thing over and over but and yet each time you *fail to provide any sources, support, or basis for your assertions*. Simply repeating yourself for the umpteenth time with some baseless analogy isn't going to cut it any more. If you're going to continue to be rude about is and call our comments nonsense and illogical then at least have the balls to back it up. No more repeating the same thing over and over. No more silly little analogies. I've provided the theory and supporting sources for what I'm saying and it's time for your to do the same. Either support you ideas with sources or let it go. I'm betting you'll just come back with some argument about it being common sense and try to leave it at that.

Mike


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## BattleScott (Aug 29, 2006)

cartrivision said:


> Actually, BattleScott's whole "explanation" completely ignores the that fact that the AZ and EL adjustments are relative to every unique vector of every plumb mast, so picking an arbitrary axes of reference for AZ and EL and saying that alignment to some other axes of reference will make the AZ or EL adjustments move on compound axes as measured against the first reference vectors, is true but completely irrelevant, because there is nothing magical or correct or true or anything else about the first vectors of reference, since EVERY such point of reference has an uniquely different angular relationship to the fixed positions of the satellites .... so which one is the "correct" one that doesn't cause movement on compound axes when changing the AZ and EL adjustments on the dish mount?
> 
> As the above simple statements of logic demonstrate, there is no one "correct" vector for the mast, because the vectors of adjustment are relative to an arbitrary set of axes, and no two plumb masts have an equivalent angular relationship to the arc of satellites in the sky.... making no single angular relationship to the arc of satellites in the sky either correct or incorrect.
> 
> In simple terms.... being out of plumb *only* means that the AZ and EL adjustments move on compound axes in relation to an irrelevant (and somewhat arbitrary) set of reference vectors that point in a different direction for every install location as measured in relation to the fixed positions of the satellites.


I don't think you understand the issue we're discussing.
The dish needs to be aimed at a precise AZ and EL, the mast being out of plumb IS going to cause some level of change in the EL setting when the AZ is adjusted and visa-versa. This error is not related to some "irrelevant" reference point, it is related to the most critical reference, the satellite's position in the sky as it relates to that particular mast. There is no disputing this, it is fact.

What we are trying to determine is how much error in plumb can be tolerated before the operater will need to go back and re-tune the axis that was previously peaked.


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## bobcamp1 (Nov 8, 2007)

MicroBeta said:


> Yes there is a correct angular relationship. It is the angle between the radius of the satellite arc and the radius of the surface of the Earth; both of which go back to the center of the Earth. This angular relationship puts the mount level on a plane tangential to that radius.
> Mike


It's not that complicated. D* uses the Horizontal Coordinate System. Which isn't perfect. No coordinate system is. The Earth is an oblate spheroid, the masts aren't at the center of the Earth, the masts are at varying altitudes, there's atmospheric refraction, and the satellites are very "close" (on the East coast, the value D* gives for tilt is approximate. We have to tinker with tilt because the arc here looks a little different than it does in the rest of the country). Yes, the horizontal coordinate system gets you close enough, but it can never get you perfect. You can be off by as much as one degree even with perfect equipment.

Which is another poor assumption. You are assuming that the markings on the dish are absolutely perfect (heck, there aren't even azimuth markings on the dish!). Even home telescope users don't make this assumption with their telescopes. Also, the mast might be plumb, but if the dish is poorly constructed it might not be plumb or may be misshaped.

Likewise, polar aligning your telescope gets you lined up with the equatorial coordinate system relative to where your telescope exactly is. And yet, when you dial up a location of a star, there is usually some fine tuning to do to get it perfectly centered, because polar alignment doesn't account for any of the problems I mentioned above. The multi-million dollar telescopes do -- which is why they are controlled by computers and motors.

Basically, I'll argue that any adjustment could move the dish in all three directions, plumb mast or not, because the coordinate system used is imperfect and so is the dish.

But since the DBS system has lots of tolerance built into it (wide cone, error correction), it just doesn't matter. The techs aren't trying to peak all three birds. They are just tweaking until the signals are "very good". That doesn't require a perfectly aligned dish.


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## Mike Bertelson (Jan 24, 2007)

bobcamp1 said:


> It's not that complicated. D* uses the Horizontal Coordinate System. Which isn't perfect. No coordinate system is. The Earth is an oblate spheroid, the masts aren't at the center of the Earth, the masts are at varying altitudes, there's atmospheric refraction, and the satellites are very "close" (on the East coast, the value D* gives for tilt is approximate. We have to tinker with tilt because the arc here looks a little different than it does in the rest of the country). Yes, the horizontal coordinate system gets you close enough, but it can never get you perfect. You can be off by as much as one degree even with perfect equipment.


Of course there's variability in the system there's no denying that. Most of that is factored into the procedures which is why with a plumb mast you only have to run the dither procedure once and you're done.


> Which is another poor assumption. You are assuming that the markings on the dish are absolutely perfect (heck, there aren't even azimuth markings on the dish!). Even home telescope users don't make this assumption with their telescopes. Also, the mast might be plumb, but if the dish is poorly constructed it might not be plumb or may be misshaped.


Actually, I'm not assuming anything. Azimuth is determined based on magnetic north so no azimuth markings needed.

All the hardware is built to some set of specs. There's no way to account for something being poorly constructed or misshapen for some reason. We have to assume the stuff is built to spec and if it looks correct it probably is. 


> Likewise, polar aligning your telescope gets you lined up with the equatorial coordinate system relative to where your telescope exactly is. And yet, when you dial up a location of a star, there is usually some fine tuning to do to get it perfectly centered, because polar alignment doesn't account for any of the problems I mentioned above. The multi-million dollar telescopes do -- which is why they are controlled by computers and motors.


It's kinda beyond the scope here but if you set the mount up correctly and sight the telescope correctly, there shouldn't be any adjustments to be made. At least that's the way its always worked for me...I'm just sayin' :grin:


> Basically, I'll argue that any adjustment could move the dish in all three directions, plumb mast or not, because the coordinate system used is imperfect and so is the dish.


The coordinate system works just fine. If you plumb the mast you dither once; not plumb then you iterate.



> But since the DBS system has lots of tolerance built into it (wide cone, error correction), it just doesn't matter. The techs aren't trying to peak all three birds. They are just tweaking until the signals are "very good". That doesn't require a perfectly aligned dish.


If the tech is following the dither procedure he/she is peaking the satellites called for other wise it's not being done correctly. The dither process in necessary because the Ka band is so much more narrow then the Ku band that you can't hit the peak with dithering.

I agree with you that a mast that's not plumb can certainly be dithered to spec. I do, however, disagree with some members reasoning for why it works the way it does.

Mike


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## BattleScott (Aug 29, 2006)

Here is a very simple way to think about it, and it also very easy to picture in your head:

Lets say we need to align a dish to a single geosychronous satellite and all we know is that it is located at 45 degrees elevation. If the mast the dish is mounted to is "perfectly plumb", you can set the elevation to exactly 45 degrees, and to find the satellite, all you would need to do is keep rotating the dish around the mast until you find the satellite.
If the mast is not plumb, lets use the previously discussed "worst case" and say it is leaning 45 degrees due south, for every one degree of azimuth rotation, the elevation is also going to change by 1 degree. So you will need to continually adjust the elevation setting as you are changing the azimuth to "find" the satellite that is somewhere along that 45 degree elevation line.


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> Here is a very simple way to think about it, and it also very easy to picture in your head:
> 
> Lets say we need to align a dish to a single geosychronous satellite and all we know is that it is located at 45 degrees elevation. If the mast the dish is mounted to is "perfectly plumb", you can set the elevation to exactly 45 degrees, and to find the satellite, all you would need to do is keep rotating the dish around the mast until you find the satellite.
> If the mast is not plumb, lets use the previously discussed "worst case" and say it is leaning 45 degrees due south, for every one degree of azimuth rotation, the elevation is also going to change by 1 degree. So you will need to continually adjust the elevation setting as you are changing the azimuth to "find" the satellite that is somewhere along that 45 degree elevation line.


There are "just a few" things here that don't work:
Due west/east would be the worst case [not south].
Due south would have the dish swing in an arc as the AZ changes, so the location would also come into play. "In Texas" [SAT due south] the first few degrees would have little/no change in EL. "In the west or east" [SAT not due south] the changes in EL would be closer to 1 to 1.
This simply points out how there can't be a "hard and fast" rule of how out of plumb before the dithering can only be done once and not have to go back and re-check the other axis.


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## cartrivision (Jul 25, 2007)

BattleScott said:


> I don't think you understand the issue we're discussing.
> The dish needs to be aimed at a precise AZ and EL, the mast being out of plumb IS going to cause some level of change in the EL setting when the AZ is adjusted and visa-versa. This error is not related to some "irrelevant" reference point, it is related to the most critical reference, the satellite's position in the sky as it relates to that particular mast. There is no disputing this, it is fact.


I've explained many times why that argument is invalid. That supposed EL change that will happen with an AZ adjustment is being measured (by you) against an arbitrary plane of reference that is different for every installation location, and additionally, that reference plane (the horizontal plane) has absolutely no meaningful angular relationship to the arc of satellites.... how could it???? It's completely random given any randomly chosen installation location.

That is the fundamental logical flaw in your's and others arguments.


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> Yes there is a correct angular relationship. It is the angle between the radius of the satellite arc and the radius of the surface of the Earth; both of which go back to the center of the Earth. This angular relationship puts the mount level on a plane tangential to that radius.


There is an _enormous_ problem with that answer......

Regardless of the elevation setting of the mount, all azimuth adjustments happen around the axis of the plumb pole, NOT AROUND THE POLAR AXIS THAT YOU SAY GIVES THE CORRECT ANGULAR RELATIONSHIP TO THE SATELLITE ARC.

That previous sentence above completely invalidates your claim that having a plumb pole gives everyone the so called "correct" angular relationship to the satellite arc.

Since the elevation adjustment on the dish mount doesn't change the axis that the azimuth adjustment happens on, there is absolutely no axis on a correctly installed and pointed DirecTV dish that is aligned with the polar axis that you claim every dish will have by virtue of being installed on a plumb mast.

Every single DirecTV dish azimuth adjustment moves the dish on an axes defined tangent to the horizontal plane that is defined by what is horizontal at every different installation location, as opposed to moving on the axis of rotation of the earth which you claim it is aligned to.

Now that that fact is established, here are some related fun facts for you to ponder....

The the AZ and EL adjustments on a DirecTV dish mount that is installed at the longitude of 101W will give the dish an arc of adjustment (on the AZ adjustment axis) that _only approaches_ being parallel to (but is still not parallel to) the arc in the sky where the satellites are (also known as the Clarke Belt), and it will give the dish an arc of adjustment (on the EL adjustment axis) that is perpendicular to the Clarke Belt arc.

But.... (and this is a huge but)....
The the AZ and EL adjustments on a DirecTV dish mount that is installed at a location such as Miami Florida will give the dish an arc of adjustment (AZ) that is significantly askew (by tens of degrees... perhaps in the neighborhood of 45 degrees askew) from the Clarke Belt arc, and it will give the dish an arc of adjustment (EL) that significantly askew (also by tens of degrees) from being perpendicular to the Clarke Belt arc.



> You would need to understand spherical coordinate systems for this to make sense...but then you wouldn't need to ask the question in the first place.


:lol::lol: :rolling: :lol::lol:
:thats: Talk about a classic case of the pot calling the kettle black.


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## RobertE (Jun 10, 2006)

:beatdeadhorse:

Around and around we go, where this arguement goes, nobody knows.


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## HoTat2 (Nov 16, 2005)

RobertE said:


> :beatdeadhorse:
> 
> Around and around we go, where this arguement goes, nobody knows.


+1 on that for sure; :nono2:

Nothing really meaningful or constructive is coming out of this banter any longer, and it's all become very personal. So can't both sides chill and just declare victory and give it a rest now? :icon_peac

Anyone can read through the numerous posts in this exchange and make up there own minds about who has the better argument.

Surprised the moderators haven't stepped in by now...


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## veryoldschool (Dec 10, 2006)

RobertE said:


> :beatdeadhorse:
> 
> Around and around we go, where this arguement goes, nobody knows.


Now how can you say this?
We're either going to learn how to do celestial navigation, or be able to adjust our dish for signals coming from Neptune.

DirecTV's training: make one set of instructions that will work for all locations, "done".
Have QA/QC follow one checklist, "done".

"I figure" it takes about 1-2 mins to dither an axis, with the fine tuning.
"I can't figure" how many I could have done instead of posting in the thread. :lol:


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> There are "just a few" things here that don't work:
> Due west/east would be the worst case [not south].


I was basically using 45 degrees as the worst case. I was not actually saying any one direction would be worse than another, only that due south would cause the 1 to 1 change in EL vs. AZ.



veryoldschool said:


> Due south would have the dish swing in an arc as the AZ changes, so the location would also come into play. "In Texas" [SAT due south] the first few degrees would have little/no change in EL. "In the west or east" [SAT not due south] the changes in EL would be closer to 1 to 1.


Why would geographic location have an impact on how much one axis changes in response to adjusting another? The "effects" of the changes might be different based on location, but if a mast in Texas is mounted with exactly the same error in plumb as a mast in Maine, they would both realize the same degree of change in axis A from adjusting axis B would they not?



veryoldschool said:


> This simply points out how there can't be a "hard and fast" rule of how out of plumb before the dithering can only be done once and not have to go back and re-check the other axis.


My example was solely intended to illustrate the fact that an out of plumb mast does have an effect on one axis when another is adjusted, a fact that Cartivision is trying to dispute. Aside from that aspect, it was not intended to be in any way relevant to alignment of specific DirecTV satellite installation.


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## BattleScott (Aug 29, 2006)

cartrivision said:


> I've explained many times why that argument is invalid. That supposed EL change that will happen with an AZ adjustment is being measured (by you) against an arbitrary plane of reference that is different for every installation location, and additionally, that reference plane (the horizontal plane) has absolutely no meaningful angular relationship to the arc of satellites.... how could it???? It's completely random given any randomly chosen installation location.
> 
> That is the fundamental logical flaw in your's and others arguments.


Other locations and arcs of satellites are irrelevant. The satellites are always in a fixed postion in the sky as they relate to my dish. If my mast is plumb I can adjust the azimuth without effecting elevation. Therefore, if my elevation was in perfect alignment and all that was needed was an adjustment to the azimuth to attain perfect signal strength, i could achieve that with only a single azimuth adjustment. If the mast is not plumb, the adjustment to the azimuth will have "some" affect on the elevation, so I might have to make a correcting adjustment to elevation to bring it back to perfect.

Sorry to say, but your's is the flawed argument.


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## BattleScott (Aug 29, 2006)

RobertE said:


> :beatdeadhorse:
> 
> Around and around we go, where this arguement goes, nobody knows.





HoTat2 said:


> +1 on that for sure; :nono2:
> 
> Nothing really meaningful or constructive is coming out of this banter any longer, and it's all become very personal. So can't both sides chill and just declare victory and give it a rest now? :icon_peac
> 
> ...


Who invited either one of you? If you're not interested, don't read it.


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> Now how can you say this?
> We're either going to learn how to do celestial navigation, or be able to adjust our dish for signals coming from Neptune.
> 
> DirecTV's training: make one set of instructions that will work for all locations, "done".
> ...


Yet, you still continue to.


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## Carl Newman (Mar 31, 2007)

It's been 40 plus years since I did any celestial navigation - but I don't remember it being nearly as complicated as the discussion in this thread. The only similarity to aligning the antenna was trying to keep the star centered in the bubble & the bubble centered in the ring while bouncing along in an aircraft at 40000 feet in the jet stream! Antenna alignment is a lot easier!

I've always thought antenna elevation was related to your latitude. And using an old rule of thumb, you'd need to move 350 miles (north or south) to have a 1 degree of change. Azimuth relates to your longitude and its difference to that of the satellite. Same 350 mile applies.

Aim and dither works fine - at least for me.

Carl


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## BattleScott (Aug 29, 2006)

Carl Newman said:


> It's been 40 plus years since I did any celestial navigation - but I don't remember it being nearly as complicated as the discussion in this thread. The only similarity to aligning the antenna was trying to keep the star centered in the bubble & the bubble centered in the ring while bouncing along in an aircraft at 40000 feet in the jet stream! Antenna alignment is a lot easier!
> 
> I've always thought antenna elevation was related to your latitude. And using an old rule of thumb, you'd need to move 350 miles (north or south) to have a 1 degree of change. Azimuth relates to your longitude and its difference to that of the satellite. Same 350 mile applies.
> 
> ...


I don't see what's so complicated about it, it's a pretty simple argument from my perspective.

My argument:
If a mast is out of plumb, any change that results in one axis from adjusting another is totally relevant to the satelites it is "looking" at. 
In most cases, would it be so small that it will not affect normal signal strengths and alignment methods? It would seem that we have answered that previously.

But there is a counter argument being made which is:
Any change in one axis due to the mast being out of plumb would have no bearing on the dishes alignment to a satelite since there is no correlation between any changes and the position of a satelite in the sky... In other words, even though the elevation of the dish is changing, it is only changing with respect to the mast, it is not changing with respect to the satelite's position?????


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## HoTat2 (Nov 16, 2005)

BattleScott said:


> Who invited either one of you? If you're not interested, don't read it.


My sincere sincere apologies for coming to this thread "uninvited" and for daring to suggest something so square and outmoded today as a truce on the hostile back and forth tone this issue appeared to degenerate into.

But please by all means continue with the war of words :bowdown: and I assure you there will be no further annoying comments from me about it....


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## David MacLeod (Jan 29, 2008)

BattleScott said:


> Who invited either one of you? If you're not interested, don't read it.


sand in giny day or is your mast not plumb?


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> Yet, you still continue to.


You asked, and I "tried to help" answer.

Going back a few posts:
Which way the mast is leaning has everything to do with these adjustments.
"Texas" was used since "your south leaning" mast would be leaning toward the AZ of the SAT. If the mast still leaned south, but your location was on the east or west coast, then it wouldn't be on the AZ, and this makes a lot of difference.
You need to understand three dimensional geometry.
If you "normalize" to which way the mast is leaning "relative to the AZ" then some common off axis assumptions can be made.
A mast leaning 45 degrees south could only be aligned at a location above 45 degrees north Lat.
As for your "worst case": it would be with the mast leaning perpendicular to the SAT AZ.


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## gfrang (Aug 30, 2007)

I think they should sell the dishes as a kit, it would include the dish;compass,map,level,wrenches,signal meter,bag of cement and pole (only if needed) and instructions with a link to this tread.
I think that's it but post anything that i missed.


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> You asked, and I "tried to help" answer.
> 
> Going back a few posts:
> Which way the mast is leaning has everything to do with these adjustments.
> ...


So then you agree with Cartrivision that the change in one axis due to adjusting another is irrelevant since the change would only be with respect to the mast and not to the position of the satelite?


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## BattleScott (Aug 29, 2006)

HoTat2 said:


> My sincere sincere apologies for coming to this thread "uninvited" and for daring to suggest something so square and outmoded today as a truce on the hostile back and forth tone this issue appeared to degenerate into.
> 
> But please by all means continue with the war of words :bowdown: and I assure you there will be no further annoying comments from me about it....


I wasn't aware there were hosilities going on, just an argument about an issue related to the thread topic.


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## BattleScott (Aug 29, 2006)

David MacLeod said:


> sand in giny day or is your mast not plumb?


Nope, just don't think people should come into a thread saying they think it should be stopped, like they're a moderator of the board. The conversation is pertinent to the thread topic. It may be totally irrelevant to the real world issues of aligning a dish, but it is still obviously relevant to those involved.


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> So then you agree with Cartrivision that the change in one axis due to adjusting another is irrelevant since the change would only be with respect to the mast and not to the position of the satelite?


I've kept away form reading Cart after the first few posts here. My eyes get crossed.
A change in one axis may or may not make a relevant change to the other axis, depending on which way the mast is leaning relative to the AZ of the SAT and the extent of the leaning. This would be consistent at all locations.
The position of the SAT(s) is a constant. The position of the dish & which way it's leaning isn't.


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## BattleScott (Aug 29, 2006)

veryoldschool said:


> I've kept away form reading Cart after the first few posts here. My eyes get crossed.
> A change in one axis may or may not make a relevant change to the other axis, depending on which way the mast is leaning relative to the AZ of the SAT and the extent of the leaning. This would be consistent at all locations.
> The position of the SAT(s) is a constant. The position of the dish & which way it's leaning isn't.


Thanks. That is the point I was trying to make, but obviously in a far less effective way.

Sorry if anything I posted in your direction was taken as rude or as a personal attack. Certainly not meant that way.


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## gfrang (Aug 30, 2007)

veryoldschool said:


> I've kept away form reading Cart after the first few posts here. My eyes get crossed.
> A change in one axis may or may not make a relevant change to the other axis, depending on which way the mast is leaning relative to the AZ of the SAT and the extent of the leaning. This would be consistent at all locations.
> The position of the SAT(s) is a constant. The position of the dish & which way it's leaning isn't.


I think what Cartrivision meant is that the mast being out of plump can never change the coordinate system,the mast mount to the dish is what is the coordinate system. What can change is it's orientation to the satellites.


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## veryoldschool (Dec 10, 2006)

BattleScott said:


> Sorry if anything I posted in your direction was taken as rude or as a personal attack. Certainly not meant that way.


I never took any of them as such.
The back and forth between a couple of others, I just had to pass over at some point.


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## joe diamond (Feb 28, 2007)

gfrang said:


> I think they should sell the dishes as a kit, it would include the dish;compass,map,level,wrenches,signal meter,bag of cement and pole (only if needed) and instructions with a link to this tread.
> I think that's it but post anything that i missed.


gfrang,
They (Directv) used to do it like that, sort of. You could buy a rig & receivers over the counter without a prescription or SBCA number. Many DIY installations are out there. Some are technically correct with superior workmanship. Others are just funny.

The theory is that the Ka/Ku dish is more than a customer can master........so they send current and former customers out to give it a shot. Sign up for an installation opportunity at Directv.com and an HSP will contact you.

There is a cool blue shirt in it for ya.

Joe


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## veryoldschool (Dec 10, 2006)

gfrang said:


> I think what Cartrivision meant is that the mast being out of plump can never change the coordinate system,the mast mount to the dish is what is the coordinate system. What can change is it's orientation to the satellites.


"In the beginning" that was the case I think as he agreed with a post of mine, but later posts went in a direction that I simply left alone and had to skip.
Some posted that the dish couldn't be aligned on an out of plumb mast, which isn't true. "Hence the myth".
Trying to come up with "how much" simply depends on too many variables, to have a "one answer fits all".


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## gfrang (Aug 30, 2007)

veryoldschool said:


> "In the beginning" that was the case I think as he agreed with a post of mine, but later posts went in a direction that I simply left alone and had to skip.
> Some posted that the dish couldn't be aligned on an out of plumb mast, which isn't true. "Hence the myth".
> Trying to come up with "how much" simply depends on too many variables, to have a "one answer fits all".


Ok if that is correct the only thing to do to align all the sats. and i think that can be done by the A axis which is the tilt.


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## veryoldschool (Dec 10, 2006)

gfrang said:


> Ok if that is correct the only thing to do to align all the sats. and i think that can be done by the A axis which is the tilt.


"Tilt" does [if the mast isn't leaning "on the AZ" to 101] come into play, which without a fine adjuster, could be the most time consuming part.


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## bobcamp1 (Nov 8, 2007)

MicroBeta said:


> Actually, I'm not assuming anything. Azimuth is determined based on magnetic north so no azimuth markings needed.
> 
> All the hardware is built to some set of specs. There's no way to account for something being poorly constructed or misshapen for some reason. We have to assume the stuff is built to spec and if it looks correct it probably is.
> 
> ...


Yikes! Azimuth is true (polar) north, not magnetic north! I hope the techs are correcting for that when they use their compasses. 

I bet the specs. and the construction isn't precise, and the tolerance is fairly big. My SL3 dish is around one degree off in elevation. The mast is plumb (I guess I should check it using spy satellites and lasers :grin. My original 18" dish came with a note with it saying that the elevation was 5 degrees off. This isn't precision equipment here.

I believe the peaking is relative for any location, not absolute. Plus the tech's not peaking all the birds simultaneously. So if he gets signals in the upper 80's after peaking one adjustment at a time he is done. Even if that same location could have gotten 90's for some or all of them with advanced techniques.


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## joe diamond (Feb 28, 2007)

bobcamp1 said:


> Yikes! Azimuth is true (polar) north, not magnetic north! I hope the techs are correcting for that when they use their compasses.
> 
> I bet the specs. and the construction isn't precise, and the tolerance is fairly big. My SL3 dish is around one degree off in elevation. The mast is plumb (I guess I should check it using spy satellites and lasers :grin. My original 18" dish came with a note with it saying that the elevation was 5 degrees off. This isn't precision equipment here.
> 
> I believe the peaking is relative for any location, not absolute. Plus the tech's not peaking all the birds simultaneously. So if he gets signals in the upper 80's after peaking one adjustment at a time he is done. Even if that same location could have gotten 90's for some or all of them with advanced techniques.


Bob,

I tried explaining true north and magnetic north to new techs years ago...plus showing a local deviation. No luck.
They just set to compass (magnetic) north and assume there is an error. When they hit the 101 they move on.

The rest of what you post is more succinctly stated than I was capable of expressing. Yes, all 5 LNBs are on the same frame. The idea is to hit a usable signal for each location.

New guys with new meters go nuts trying to get big numbers from all sats.

Joe


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## veryoldschool (Dec 10, 2006)

joe diamond said:


> New guys with new meters go nuts trying to get big numbers from all sats.
> 
> Joe


Until they look at their paychecks.


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## cartrivision (Jul 25, 2007)

BattleScott said:


> Other locations and arcs of satellites are irrelevant. The satellites are always in a fixed postion in the sky as they relate to my dish. If my mast is plumb I can adjust the azimuth without effecting elevation. Therefore, if my elevation was in perfect alignment and all that was needed was an adjustment to the azimuth to attain perfect signal strength, i could achieve that with only a single azimuth adjustment. If the mast is not plumb, the adjustment to the azimuth will have "some" affect on the elevation, so I might have to make a correcting adjustment to elevation to bring it back to perfect.
> 
> Sorry to say, but your's is the flawed argument.


The above argument so logically flawed that it's comical. Your complete inability to see the simple logical errors in your argument is dumbfounding.

The plane of adjustment that you are calling "elevation" is not absolute, it's relative, and it's completely different for every plumb pole, so the fact that your azimuth adjustment doesn't change anything on your unique elevation plane is completely irrelevant.

If I adjust the elevation on the mount on my plumb mast, that would also change the azimuth... * if I used your definition of azimuth that exists for your plumb mast at your location*... but I don't.... just like you and everyone else, I use the definition of azimuth that is defined by the direction that my mast is pointing in, *therefore all elevation adjustments on my mount are perfectly perpendicular to the azimuth adjustments of my mount, regardless if my mast is perfectly plumb or 45 degrees off plumb.*

If your theory is correct, you should be able to answer these simple questions....

How does the plane or direction that _your_ elevation adjustment happens on relate to the arc of satellites? Does it cause your azimuth adjustments to happen at some "correct" angle in relationship to the arc of satellites? Explain what makes that angle of azimuth adjustment more "correct" than if the mast was 15 degrees off plumb in any direction.

Your inability to answer those simple questions demonstrates that you have little understanding of the basics of this subject in addition to having no logical basis backing your argument.

To beat this dead horse even deader and demonstrate how you theory is completely illogical and nonsensical.......

For someone living in Florida, a plumb mast will cause their elevation adjustment to move at about a 45 degree angle in relation to the arc of the satellites, while for someone living in the middle of North Dakota a plumb mast will cause their elevation adjustment to move almost exactly perpendicular to the arc of satellites.... so which is the correct angle of adjustment when doing the elevation adjustment??? Is the correct plane of adjustment the one that moves the dish at a 45 degree angle across the arc of satellites, or the one that moves it exactly perpendicular to the arc of satellites???

Your inability to answer those simple questions demonstrates that you have little understanding of the basics of this subject in addition to having no logical basis backing your argument.

Given the indisputable fact that everyone's mast is pointing in a different direction, your argument that a plumb mast somehow gives some "correct" angle of alignment in relation to the position of the arc of satellites is beyond absurd and it's completely contradicted by simple logic.

If there was a "correct" relational angle of the mast to the arc of satellites, then the direction that everyone's mast pointed would have to be the same instead of allowing them all to be pointing in different directions.

INSTEAD OF JUST REPEATING OVER AND OVER THAT YOU ARE RIGHT AND I AM WRONG, DEMONSTRATE THE ERROR IN MY SIMPLE LOGICAL STATEMENTS THAT DIRECTLY INVALIDATE YOUR SERIOUSLY FLAWED ARGUMENT. THE FACT IS... YOU CAN'T DO THAT BECAUSE YOUR THEORY IS TOTAL NONSENSE AND COMPLETELY UNSUPPORTED BY SIMPLE LOGIC.... HENCE YOUR CONTINUED FAILURE TO SUPPORT IT.


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## veryoldschool (Dec 10, 2006)

And here I thought this would drop off page 1, well it almost did.


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## cartrivision (Jul 25, 2007)

BattleScott said:


> I don't see what's so complicated about it, it's a pretty simple argument from my perspective.
> 
> My argument:
> If a mast is out of plumb, any change that results in one axis from adjusting another is totally relevant to the satelites it is "looking" at.
> In most cases, would it be so small that it will not affect normal signal strengths and alignment methods? It would seem that we have answered that previously.


We have not answered that previously. Every time I have asked what that supposed "correct" orientation of the axes of adjustment (in relation to the arc of satellites) must be so as to not affect normal alignment methods, all I see in response is continued failure to answer that question.

The relevant questions are.... Should the elevation adjustment move the dish perpendicular to (or at some other "correct" angle) in relation to the arc of the satellites? How should the azimuth adjustment axis move in relation to that same fixed arc of satellites in the sky in order to be "correct"?

The reason that nobody can or has answered those questions is because not only is there no "correct" orientation of the two adjustment axes relative to the arc of satellites, since by simple logic, every dish mount at every different location has a different orientation of it's adjustment axes in relation to that arc of satellites, and some of those differences can be very significant (greater than 45 degrees).



> But there is a counter argument being made which is:
> Any change in one axis due to the mast being out of plumb would have no bearing on the dishes alignment to a satelite since there is no correlation between any changes and the position of a satelite in the sky... In other words, even though the elevation of the dish is changing, it is only changing with respect to the mast, it is not changing with respect to the satelite's position?????


To try to clear up some of the confusion, if the dish mount is moved on it's azimuth axis, the orientation of the mast and/or mount will not change how the elevation adjustment moves in relation to that first azimuth adjustment. It will always be perpendicular to the azimuth adjustment direction no matter which way the mast is pointed... which is why being out of plumb (even significantly) will never make the elevation adjustment move in a direction other than perpendicular to the azimuth adjustment.

Also of importance in this discussion is the fact that neither of the arcs of adjustment have any significant or required relationship to the arc of satellites in the sky. This is made evident by the fact that the angular relationship of the adjustment axes to the satellite arc is different for every different install location.

The arc of the satellites only comes into play for the dish tilt adjustment. Once the center LNB is precisely focused on the satellite at the center of that arc (the 101 satellite), then it's just a matter of having the correct tilt so that an arc running through all of the LNB focal points is parallel to the arc that runs through the set of 3-5 satellites of interest.


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## gfrang (Aug 30, 2007)

joe diamond said:


> gfrang,
> They (Directv) used to do it like that, sort of. You could buy a rig & receivers over the counter without a prescription or SBCA number. Many DIY installations are out there. Some are technically correct with superior workmanship. Others are just funny.
> 
> The theory is that the Ka/Ku dish is more than a customer can master........so they send current and former customers out to give it a shot. Sign up for an installation opportunity at Directv.com and an HSP will contact you.
> ...


I forgot to include a Happy meal and TP.


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## BattleScott (Aug 29, 2006)

cartrivision said:


> We have not answered that previously. Every time I have asked what that supposed "correct" orientation of the axes of adjustment (in relation to the arc of satellites) must be so as to not affect normal alignment methods, all I see in response is continued failure to answer that question.


Yes, we have answered the question. The one that was asked, not what you are asking here.



cartrivision said:


> The relevant questions are.... Should the elevation adjustment move the dish perpendicular to (or at some other "correct" angle) in relation to the arc of the satellites? How should the azimuth adjustment axis move in relation to that same fixed arc of satellites in the sky in order to be "correct"?.


No, the relevant question is "should the elevation change when the azimuth is adjusted and visa-versa?" The correct answer is of course "no", and a plumb mast is the only way to prevent that.



cartrivision said:


> The reason that nobody can or has answered those questions is because not only is there no "correct" orientation of the two adjustment axes relative to the arc of satellites, since by simple logic, every dish mount at every different location has a different orientation of it's adjustment axes in relation to that arc of satellites, and some of those differences can be very significant (greater than 45 degrees).


Every dish in every location is the same in that if the mast is not plumb, an adjustment to one axis can induce a change in the other as they relate to a fixed point, or points in this case, in the sky.



cartrivision said:


> To try to clear up some of the confusion, if the dish mount is moved on it's azimuth axis, the orientation of the mast and/or mount will not change how the elevation adjustment moves in relation to that first azimuth adjustment. It will always be perpendicular to the azimuth adjustment direction no matter which way the mast is pointed... which is why being out of plumb (even significantly) will never make the elevation adjustment move in a direction other than perpendicular to the azimuth adjustment.


The only confusion here is yours and your own paragraph should help you see that. You clearly indicate that an out-of-plumb mast CAN cause one axis to change in response to the other being adjusted which is what we have been discussing.

We are not talking about a mast being out of plumb changing how the axis move in RELATION to each other. We are talking about one axis changing in RESPONSE to the other being changed. Whether the movement is perpendicular to the other axis or not, it is not good that it moves at all because it is moving in relation to the position of the satelites. If my elevation is correctly set, I certainly don't want it to move in response to changing the azimuth setting, be it perpendicular or not. I want it to stay where it is.



cartrivision said:


> Also of importance in this discussion is the fact that neither of the arcs of adjustment have any significant or required relationship to the arc of satellites in the sky. This is made evident by the fact that the angular relationship of the adjustment axes to the satellite arc is different for every different install location.
> 
> The arc of the satellites only comes into play for the dish tilt adjustment. Once the center LNB is precisely focused on the satellite at the center of that arc (the 101 satellite), then it's just a matter of having the correct tilt so that an arc running through all of the LNB focal points is parallel to the arc that runs through the set of 3-5 satellites of interest.


While fascinating and educational to be sure, this portion really has no relevance to the discussion at hand which is that an out of plumb mast can cause one axis to change in response the adjustment of another as they relate to a fixed point (or points) in the sky. However, the degree it would need to be out would have to be fairly large before it would have a significant impact.


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> There is an _enormous_ problem with that answer......
> 
> Regardless of the elevation setting of the mount, all azimuth adjustments happen around the axis of the plumb pole, NOT AROUND THE POLAR AXIS THAT YOU SAY GIVES THE CORRECT ANGULAR RELATIONSHIP TO THE SATELLITE ARC.
> 
> That previous sentence above completely invalidates your claim that having a plumb pole gives everyone the so called "correct" angular relationship to the satellite arc.


Just because you type a sentence out doesn't invalidate anything anyone else has posted. It might if you could *show *it to be true...a little math or maybe a website that shows the theory. Creating analogies to fit your view of how it works doesn't in any way, shape, or form mean you started with a sound opinion in the first place. *Just because you post it, doesn't make it true*.

It's apparent that no one here can have a civil discussion with you as you continue to berate and belittle others posts. Even when others have provided corroborating sources you respond rudely and dismiss those sources as not applying to this situation. Yet, you still are unable to support a single thing that you have posted in this thread nor have shows any support for how your view applies.

If you could have come up with something, anything that supported your view we could have had a pretty cool discussion. Anyone who knows me knows I admit when I'm wrong...heck I've done it here more then once and will probably do it again. You can't have six thousand post and be right everytime. The trick is to own up to it and I'm smart enough to know that I don't know it all. 

I guess the readers will have to decide for themselves what makes the most sense. If they base their decision on the installation procedure and the supporting info in the provided links as well as their own research, I'm sure they will be able to do it correctly. IMHO, that if you're a novice DIYer then you should always start with a plumb mast and follow the procedure. If properly followed, the procedure will work every time. Installers know how to deal with many different situations so this discussion wasn't really for them. Any tech worth his/her salt will dither it spot on everytime, plumb or not. 

I wish we could've compared facts instead of opinions and have done it in a civil manner. It had potential to be an interesting technical discussion.

I apologize to everyone if I've come rude to as that wasn't my intention. Life has a way of pointing you back in the right direction.

Since there can be no civility it's time to let this one fade on to page 2 and beyond.

Mike


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## bobcamp1 (Nov 8, 2007)

cartrivision said:


> To try to clear up some of the confusion, if the dish mount is moved on it's azimuth axis, the orientation of the mast and/or mount will not change how the elevation adjustment moves in relation to that first azimuth adjustment. It will always be perpendicular to the azimuth adjustment direction no matter which way the mast is pointed... which is why being out of plumb (even significantly) will never make the elevation adjustment move in a direction other than perpendicular to the azimuth adjustment.
> 
> The arc of the satellites only comes into play for the dish tilt adjustment. Once the center LNB is precisely focused on the satellite at the center of that arc (the 101 satellite), then it's just a matter of having the correct tilt so that an arc running through all of the LNB focal points is parallel to the arc that runs through the set of 3-5 satellites of interest.


Now I think I know why you are confused. The Horizontal Coordinate System always uses the horizon, never the pole, as its point of reference. No one really talks about the coordinate system of each individual telescope or mast. I suppose in theory each pole has its own unique system, but it's never thought of like that, since you can't translate that coordinate system to anything useful.

Also, the satellite arc looks so different between the coasts that it impossible to get a perfect installation. The focal points of the LNB never perfectly runs through the satellites of interest. The guess is that the dish is built for the West Coast, and the East coast just lives with each installation being imperfect.

The good news is that we aren't looking at faint stars. We are looking at objects that are much "brighter" and maybe even "bigger" than planets. So close enough is good enough.


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## TomCat (Aug 31, 2002)

sstv said:


> Hi All
> We have all read about how the dish mast must be plumb and no matter what happens after a installation, a plumb mast is a must.
> I don't think this is true. A plumb mast and using the coordinates will get you into the ball park quickly after that its a matter of tweaking Tilt, Elevation and Azimuth.
> This tweaking can be done even if the mast is not plumb it just takes a little longer and the results are the same.
> ...


You are correct, sir. Thanks for posting this.

The "plumb mast" myth probably stems from the days of backyard C-band steerable dishes, which were horizon-to-horizon or polar mount rather than AZ-EL. There was a setting called "declination" which was an offset that raised the elevation as it approached the center of arc and lowered it as it went beyond the center of arc, up to 8 degrees depending upon how far north you were, allowing the dish to track a curved arc.

If you think about it, the Clarke belt appears as a straight line (directly overhead) at the equator, and as an increasing curved line (increasingly lower in the sky) as you migrate north or south of the equator, that line or arc increasing in curvation the farther from the equator you go. A non-plumb mast made it difficult to set this properly especially in the northern climes, and if not plumb it was a bit of a compromise to get max signal for the entire arc.

But a fixed dish always points where it points (kind of how it got the name "fixed"), even if it points at 5 sats at once. There is no worry because the "plumb-ness" of the mast can be compensated for fully by a clever thorough install. The dish has no earthly idea whether it is sitting on a mast or not, plumb or not. It just knows it has to continue to point in a particular direction (also with a particular yaw orientation), which is possible even without a mast at all.



cartrivision said:


> ...Also of importance in this discussion is the fact that neither of the arcs of adjustment have any significant or required relationship to the arc of satellites in the sky. This is made evident by the fact that the angular relationship of the adjustment axes to the satellite arc is different for every different install location.
> 
> The arc of the satellites only comes into play for the dish tilt adjustment. Once the center LNB is precisely focused on the satellite at the center of that arc (the 101 satellite), then it's just a matter of having the correct tilt so that an arc running through all of the LNB focal points is parallel to the arc that runs through the set of 3-5 satellites of interest.


Very true. While also not dependent on a plumb mast, the multi-sat DBS dish looks at only a small slice of the arc (20 degrees for the SL5, 10 for the SL3) which while actually curved can be thought of as a "straight" line regardless of how far north you are (in fact, the antenna design probably straddles the difference between the 8-degree declination offset in International Falls, MN and the 3-degree declination in Key West, FL. IOW, the LNBs are likely not in a straight line, but in a 5-6 degree arc relative to each other to better match the curve of that tiny slice of the arc, with enough fudge factor to accept a declination offset error of 2-3 degrees for the entire arc, which would be a much tinier error factor for only 10 or 20 degrees, and probably not even measurable at a vertically-central location such as Denver CO). The SL5 installation, for instance, aligns two of the 5 sats only, the second sat being in effect an attempt to place the angular adjustment of that "slice" in line with that part of the arc.


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## HoTat2 (Nov 16, 2005)

TomCat said:


> ...While also not dependent on a plumb mast, the multi-sat DBS dish looks at only a small slice of the arc *(20 degrees for the SL5, 10 for the SL3)* which while actually curved can be thought of as a "straight" line regardless of how far north you are (in fact, the antenna design probably straddles the difference between the 8-degree declination offset in International Falls, MN and the 3-degree declination in Key West, FL. IOW, the LNBs are likely not in a straight line, but in a 5-6 degree arc relative to each other to better match the curve of that tiny slice of the arc, with enough fudge factor to accept a declination offset error of 2-3 degrees for the entire arc, which would be a much tinier error factor for only 10 or 20 degrees, and probably not even measurable at a vertically-central location such as Denver CO). The SL5 installation, for instance, aligns two of the 5 sats only, the second sat being in effect an attempt to place the angular adjustment of that "slice" in line with that part of the arc.


You said a 10 degree purview of the geostationary orbital arc for the SlimLine-3? 99-103 degrees is 4 degrees isn't it, or am I missing something?


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## BKC (Dec 12, 2007)

I think the time has come. Ok guys whip em out on the coffee table beside a ruler and we'll see who wins.....


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## cartrivision (Jul 25, 2007)

Sorry to bring this thread back from the dead, but I just can't let such ridiculously false and absurd statements go unanswered.



BattleScott said:


> No, the relevant question is "should the elevation change when the azimuth is adjusted and visa-versa?" The correct answer is of course "no", and a plumb mast is the only way to prevent that.


That's not the relevant question because it's based on the totally incorrect assumption that what you are calling elevation and azimuth are some movements in some constant coordinate system with a fixed relationship to the arc of satellites (or a fixed relationship to any other arc or vector anywhere in space) given a plumb pole installation from any location on earth.

That simply is not true. For a plumb pole, azimuth and elevation are not a fixed or constant coordinate system (given plumb poles at different locations on earth), but a differently oriented coordinate system for every different plumb pole location. From some locations, that relative coordinate that is called elevation intersects the arc that the satellite reside on at almost exactly a 90 degree angle, and from other locations on earth that elevation movement will intersect that arc at a skew of 45 degrees or more.

Which one is correct? The coordinate system where "elevation" movements intersect that satellite arc at 90 degrees or the one where "elevation" movements intersect it at 45 degrees? Why can't you answer that simple question?



> Every dish in every location is the same in that if the mast is not plumb, an adjustment to one axis can induce a change in the other as they relate to a fixed point, or points in this case, in the sky.


More absolutely and completely irrelevant nonsense. As pointed out above, what you are calling the the elevation and azimuth axes are different coordinate systems for every plumb pole at a different location on earth, and none of those different coordinate systems have a constant or "correct" relationship to the satellite arc. For the vast majority of plumb pole installations, adjusting the elevation setting on the dish mount moves the dish in a direction that is nowhere near to perpendicular to the satellite arc.



> The only confusion here is yours and your own paragraph should help you see that. You clearly indicate that an out-of-plumb mast CAN cause one axis to change in response to the other being adjusted which is what we have been discussing.
> 
> We are not talking about a mast being out of plumb changing how the axis move in RELATION to each other. We are talking about one axis changing in RESPONSE to the other being changed. Whether the movement is perpendicular to the other axis or not, it is not good that it moves at all because it is moving in relation to the position of the satelites. If my elevation is correctly set, I certainly don't want it to move in response to changing the azimuth setting, be it perpendicular or not. I want it to stay where it is.


This is absolute and total nonsense. Again, it completely ignores the simple fact that what you are calling elevation and azimuth are movements in different directions for every plumb pole at every different location on earth, yet you ignorantly insist that every one of those differently oriented coordinate systems somehow all have the "correct" two axes of adjustment.

Your argument fails on a very simple application of logic. If there is a single "correct" coordinate system that elevation and azimuth adjustments must happen on, that absolutely does not and will not occur when every pole is plumb. That is a simple fact that you and others offering the same argument have consistently failed to address.



> While fascinating and educational to be sure, this portion really has no relevance to the discussion at hand which is that an out of plumb mast can cause one axis to change in response the adjustment of another as they relate to a fixed point (or points) in the sky. However, the degree it would need to be out would have to be fairly large before it would have a significant impact.


More complete nonsense that continues to ignore the simple fact that everyone's elevation and azimuth adjustments move their dish in a direction that is not only skewed from other people's definition of elevation and azimuth, but is also differently skewed from the arc of the Clarke belt that the satellites reside on, and differently skewed from any other constant coordinate system in space.


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## Mike Bertelson (Jan 24, 2007)

cartrivision said:


> Sorry to bring this thread back from the dead, but I just can't let such ridiculously false and absurd statements go unanswered.


With your confrontational approach no one will believe a word you say on this subject unless you can back it up. If you are correct there will be some simple geometry/trigonometry to support your argument.

You are so adamant that you *need* to correct "ridiculously false and absurd statements" so either prove it or let it go (and really, I don't know why you need to be so rude and condescending about it). If your explanations, analogies, and "simple' questions are based on a false premise you won't be able to.

If you continue on your rude condescending rants this thread will likely be closed; however, if you can provide some supportable information _and_ be civil about we might just have an interesting informative discussion.

So, can you support your premise with anything other then your opinion...IOW with tangible, verifiable sources?

Mike


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## bobcamp1 (Nov 8, 2007)

I stand by my previous post. Cartrivision's last post is still consistent with my theory about why he's still confused.

Battlescott is still confused because he thinks he's tracking moving satellites instead of simply trying to aim a cheap, deformed, crooked dish using a cheap, crooked (but perfectly plumb) pole towards a stationary target using approximate coordinates. And on the East coast, the arc is guaranteed to be misshapen so tuning is almost guaranteed.

TomCat seems to grasp the concept perfectly, except what he means to say is that this system, which D* uses:

http://en.wikipedia.org/wiki/Horizontal_coordinate_system

is different than this system:

http://en.wikipedia.org/wiki/Equatorial_coordinate_system

Now he needs to run as far away from this thread as he can!

I'm running from it too. Without a face-to-face conversation, it is difficult to get some to unlearn what they have learned and reteach them correctly.


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## Mike Bertelson (Jan 24, 2007)

bobcamp1 said:


> I stand by my previous post. Cartrivision's last post is still consistent with my theory about why he's still confused.
> 
> Battlescott is still confused because he thinks he's tracking moving satellites instead of simply trying to aim a cheap, deformed, crooked dish using a cheap, crooked (but perfectly plumb) pole towards a stationary target using approximate coordinates. And on the East coast, the arc is guaranteed to be misshapen so tuning is almost guaranteed.
> 
> ...


You and TomCat are 100% correct and it is the Horizon Coordinate System that applies to this specific situation. The horizon coordinate, equatorial coordinate, and celestial coordinate systems are all based on a spherical coordinate system. They're all different applications of the same principals. BTW, that first link is an excellent one and probably the best one so far. Very Cool. 

Some people need to understand the horizon coordinate systems and spherical coordinate systems as a whole in order to understand why it works the way it does...I'm just sayin' :grin:

Mike


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## BattleScott (Aug 29, 2006)

bobcamp1 said:


> Battlescott is still confused because he thinks he's tracking moving satellites instead of simply trying to aim a cheap, deformed, crooked dish using a cheap, crooked (but perfectly plumb) pole towards a stationary target using approximate coordinates.


Please link a single post of mine, from this or any other thread, that even remotely supports this completely backwards statement.

I'll link to *this one *just to show you how wrong you are.

p.s.: I was perfectly willing to stay out of this until I was called by name.


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## Mike Bertelson (Jan 24, 2007)

BattleScott said:


> Please link a single post of mine, from this or any other thread, that even remotely supports this completely backwards statement.
> 
> I'll link to *this one *just to show you how wrong you are.
> 
> p.s.: I was perfectly willing to stay out of this until I was called by name.


Well, FWIW, I agree with your linked post. :grin:

Mike


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## bobcamp1 (Nov 8, 2007)

BattleScott said:


> No, the relevant question is "should the elevation change when the azimuth is adjusted and visa-versa?" The correct answer is of course "no", and a plumb mast is the only way to prevent that.
> 
> ... If my elevation is correctly set, I certainly don't want it to move in response to changing the azimuth setting, be it perpendicular or not. I want it to stay where it is.
> 
> ...However, the degree it would need to be out would have to be fairly large before it would have a significant impact.


Jumping back in to apologize. Didn't see your last statement in your last post. Sorry about that. 

Here's what got me confused in your last post. The first statement should be "DOES the elevation change when azimuth is adjusted, and the answer is always 'yes'. There are too many imperfections. Getting the mast perfectly plumb helps a little, getting it reasonably plumb helps more. But who cares -- it's a one-time adjustment and you get instant feedback on how well you're doing."

Second statement should say, "My elevation will always move when I change the azimuth setting. But who cares -- it's a one-time adjustment."

The statement I make is, "go look outside and record the elevation, tilt, and guess what the azimuth is (shudder -- it's not even on the dish, huge inaccuracy there) on your dish. Now go check how plumb the mast is (assuming you didn't fill it). Now ask the receiver where the satellites should be. Are they all within 0.5 degrees of the expected values?". I went out again last night. All of my dish readings are 2 degrees off, the azimuth is around 5 degrees off. During installation, the mast was plumb within 0.4 degrees (it's not off by more than 0.5" over the 72" pole, I used a plumb line and a level to verify). I get low to upper 90s on signal strength.

I was careful to make my mast plumb, but after I saw how far off the dish itself was I said, "why did I bother to do that?".


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## joe diamond (Feb 28, 2007)

bobcamp1 said:


> Jumping back in to apologize. Didn't see your last statement in your last post. Sorry about that.
> 
> Here's what got me confused in your last post. The first statement should be "DOES the elevation change when azimuth is adjusted, and the answer is always 'yes'. There are too many imperfections. Getting the mast perfectly plumb helps a little, getting it reasonably plumb helps more. But who cares -- it's a one-time adjustment and you get instant feedback on how well you're doing."
> 
> ...


Again,

The plumb mast just makes it easier.
With the return of the bigger dishes it has again become important to make sure the settings that are tuned at installation stay where they are put. This means monopoles, whatever it takes to get a firm attachment to existing soil or on a structure and checking things again after all work is finished. Conditions vary but the need for good tuning and a clear LOS are the constants.

Joe


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## cartrivision (Jul 25, 2007)

MicroBeta said:


> With your confrontational approach no one will believe a word you say on this subject unless you can back it up. If you are correct there will be some simple geometry/trigonometry to support your argument.
> 
> You are so adamant that you *need* to correct "ridiculously false and absurd statements" so either prove it or let it go (and really, I don't know why you need to be so rude and condescending about it). If your explanations, analogies, and "simple' questions are based on a false premise you won't be able to.
> 
> ...


I have supported and proved it with very simple statements of fact that you or anyone else have been unable to show to be false, but since that you seem to have missed those simple irrefutable statements, I'll repeat them again and invite you to refute them if you think you can......

What we all are calling the the elevation and azimuth axes (from the perspective of your plumb pole) are differently oriented coordinate systems for every plumb pole at a each different location on earth, and furthermore, none of those different coordinate systems have a constant or "correct" relationship to the satellite arc. For the vast majority of plumb pole installations, adjusting the elevation setting on the dish mount moves the dish in a direction that is not perpendicular to the satellite arc.

Everyone's elevation and azimuth adjustments move their dish in a direction that is not only skewed from other people's definition of elevation and azimuth, but is also differently skewed from the arc of the Clarke belt that the satellites reside on, and differently skewed from any other constant coordinate system in space.

Every one of those differently oriented coordinate systems which all intersect the arc of satellites at different angles cannot possibly be moving along some theoretical "correct" two axes of adjustment, since every one of them has a different orientation with no fixed or constant relationship to the arc of the satellites (or any other constant reference point, line, or arc).

Please refute any of the above statements if they are incorrect by stating exactly what is incorrect about them.

Also, please explain what you think the "correct" orientation of the adjustment axis should be in relation to the arc that the satellites lie upon. Must the elevation adjustment on the dish mount move the dish perpendicular to that arc? If not, what it the "correct" direction of movement for the elevation adjustment in relation to that arc, and how does having a plumb pole assure that that "correct" direction of movement in relation to the arc of the satellites?

To help you get started, I'll point out yet another irrefutable fact.... with my perfectly plumb pole in the Los Angeles area, the elevation adjustment on my Slimline dish mount will not move my dish on along an axis that is even near to being perpendicular to the arc of the satellites, and yet there are locations in Texas where with a perfectly plumb pole the elevation adjustment will move the dish along an axis that is exactly perpendicular to the arc of the satellites.

I eagerly await your answers to the above questions. Since I am so wrong :lol:, I'm sure it will be a piece of cake for you or anyone else to point out what is false about my statements above, and to answer my very simple question about how the axis of the elevation adjustment must relate to the arc of the satellites in order for it to be "correct".


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## doctor j (Jun 14, 2006)

Cartrivision!

COME ON MAN!!!

Your statements on celestial geometry are correct.

However !, it is also correct, that for the uninitiated, a starting point that is "off axis" ie not plumb ,makes adjustments more difficult. They become 3 dimensional rather than 2 dimentional and thus much more difficult for the "average user". 

If you insist on being"correct" as opposed to being practical, there is no defense. You are right! Your logic is unrefutible! 

However the common man will still spend hours trying to find his simple satellite TV service w/o success if his mast is not nearly plumb.

If the mast is plumb, and correct AZ,EL,TILT co-ordinates are known, "EVEN A CAVE MAN CAN DO IT".

I hope you feel GOOD by being CORRECT.

Doctor j 
"an unsupportive, equally anal retentive , obsessive-compulsive nerd"


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## Doug Brott (Jul 12, 2006)

Not sure why we needed to resurrect a 6-week dead thread .. 

Either way .. I eyeballed my mast threw a dish on it .. put a receiver and TV close by and tweaked it using the dithering method .. up in the high 80s low 90s in just a few minutes and called 'er good. Next!


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## cartrivision (Jul 25, 2007)

doctor j said:


> Cartrivision!
> 
> COME ON MAN!!!
> 
> ...


I'm sorry, but that is just a "hand waving" explanation that not backed by any logical statements of fact.

As I have pointed over and over again, for different locations on the Earth's surface, the axes of adjustment of a dish mount that is on a perfectly plumb pole will have an different relationship to the arc in the sky on which all the geostationary satellites lie.

That simple fact that nobody can refute means that every single plumb pole installation has adjustment axes that are different (don't move in the same direction) for every different pole location.

Given the simple irrefutable fact that every installation has their own unique axes of adjustment that are not the same as anyone else's axes of adjustment (i.e. they all are oriented/skewed differently with reference to the arc of satellites), how can all of those different orientations of the az/el adjustment axes ALL have some supposed "correct" direction of movement that you and others say makes adjustments "less difficult for the average user".

I keep asking that question and nobody can answer it. Can you?

How can the adjustment axes of all the plumb pole mounts all be oriented differently and at the same time all be oriented to move in the "correct" direction?

I keep asking that question and nobody can answer it. Can you?

What is the "correct" or optimal orientation of the adjustment axes with relation to to the arc of satellites that is being aimed at?

I keep asking that question and nobody can answer it. Can you?

You clearly think that there is some "correct" orientation of those adjustment axes, so what is it? How should such optimally oriented elevation and azimuth adjustments move the dish in relation to that arc of satellites?

Should the elevation adjustment on the dish mount move the dish along an axis that is perfectly perpendicular to the arc of the satellites? If not, what is the correct direction for that axis of adjustment?

Why can't anyone answer these questions?

If there is a "correct" or "optimal" orientation for the az/el adjustments as they relate to the positions of the satellites that are being aimed at, please state what it is.

The inability of anyone to answer these simple questions effectively shows that there is no one "correct" orientation of the adjustment axes, and furthermore if there was, putting the dish mount on a plumb pole couldn't possibly insure that one correct orientation of the adjustment axes since every plumb pole in every different location points in a different direction.


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## cartrivision (Jul 25, 2007)

Doug Brott said:


> Not sure why we needed to resurrect a 6-week dead thread ..


Because people keep posting "hand waving" explanations of what a plumb pole does for you without providing logical factual statements supporting that supposition, and because every time I ask someone to demonstrate any factual error in the simple statements that I keep making which support my contention, nobody can demonstrate any such factual error, and they instead just repeat their error ridden theories without any supporting logic.

If all this bores you and/or you don't care to learn why a plumb pole does not provide an optimal or "correct" orientation of the dish adjustment axes, or you prefer to believe (as incorrect as it is) the supposition that a plumb pole gives you and everyone else some kind of optimally oriented dish adjustment axes (which are somehow all correct and all the same despite being referenced to poles which are all pointing in different directions), continued reading of this thread is probably not advisable.


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## veryoldschool (Dec 10, 2006)

cartrivision,
You went off the deep end over this so long ago, I simply passed over your posts for a long time, but why in the world you've decided to drag this up again is a mystery. :shrug:

I've posted from my first that the pole doesn't need to be "plumb" [plumb is like being pregnant, you are or you're not, as plumb, it is or it's not, there is no degree of this].

If you start with a "plumb" pole, then you can align the dish quicker, as the listed settings for the location will work with less "fiddling".
The farther out of plumb the mast is, the more you need to compensate by deviating from the listed [basic] settings. The installer needs to have an understanding of which setting needs to be adjusted to compensate for the lean.
This could/will take a bit more time to do.
If you're not being paid or are being paid by the hour, you can spend all the time you need to get the dish aligned well.
If you're being paid a flat rate for the job, then you want to do the job as quickly as you can, and "fiddling" with the dish is costing you money.

Without going into astrophysics, has this answered your questions?


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## Doug Brott (Jul 12, 2006)

cartrivision said:


> If all this bores you and/or you don't care to learn why a plumb pole does not provide an optimal or "correct" orientation of the dish adjustment axes, or you prefer to believe (as incorrect as it is) the supposition that a plumb pole gives you and everyone else some kind of optimally oriented dish adjustment axes (which are somehow all correct and all the same despite being referenced to poles which are all pointing in different directions), continued reading of this thread is probably not advisable.


Yeah, thanks for that tidbit ..  .. But really, everyone else did move on. You're the only one left at this point .. So I will not return and I encourage others to do the same as the point of this discussion is no longer the topic of this thread.


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## cartrivision (Jul 25, 2007)

veryoldschool said:


> cartrivision,
> You went off the deep end over this so long ago, I simply passed over your posts for a long time, but why in the world you've decided to drag this up again is a mystery. :shrug:


Because people keep saying that there is a "correct" orientation of the adjustment axes that allows the fine tuning adjustment axes to be done on "one axis at a time", but nobody who says that can describe this supposedly "correct" adjustment axes orientation in relation to the arc of satellites that we are aiming at.

I'm aiming at satellites in the sky, so if there is some "correct" orientation of the axes of adjustment, I need to know what it is in relation to the objects that I'm aiming at. I don't even need an explanation of how a plumb pole will achieve that correct orientation of the adjustment axes with relation to the satellite arc... I just want someone to tell me what the "correct" orientation is using the constant position of the satellites (which defines a constant arc in the sky) as a reference point.

I'll stop responding to the "correct adjustment axes orientation" crowd and declare myself wrong when any one of them can answer that very simple question.



veryoldschool said:


> I've posted from my first that the pole doesn't need to be "plumb" [plumb is like being pregnant, you are or you're not, as plumb, it is or it's not, there is no degree of this].
> 
> If you start with a "plumb" pole, then you can align the dish quicker, as the listed settings for the location will work with less "fiddling".
> 
> ...


You are not saying anything that I disagree with. I have said long ago that that there is one and only reason that a plumb pole would ever matter, and that is that it allows you to use the AZ/EL numbers calculated for your unique location to get the initial rough fix on the 101 satellite. Those numbers are calculated for a plumb pole, but they could just as easily be calculated for a pole that was leaning to the north by 10 degrees, and everything would still work the same.

Other than for that purpose of using those calculated numbers to get the rough fix on the 101 sat, a plumb pole is completely irrelevant to the rest of the adjustment process... which is what my whole argument has been about.

It doesn't make fine tuning adjustments happen on a singular axes of any coordinate system that has a constant fixed relationship to the objects being aimed at... it cant, because a plumb pole defines a differently oriented coordinate system (in relation to the satellite arc) from every different location on earth.


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## veryoldschool (Dec 10, 2006)

With three axis adjustments [right/left, up/down, & right/left rotation], one could mount a dish upside down or sideways and if they didn't run out of adjustments, could align the dish.


> I'm aiming at satellites in the sky, so if there is some "correct" orientation of the axes of adjustment, I need to know what it is in relation to the objects that I'm aiming at. I don't even need an explanation of how a plumb pole will achieve that correct orientation of the adjustment axes with relation to the satellite arc... I just want someone to tell me what the "correct" orientation is using the constant position of the satellites (which defines a constant arc in the sky) as a reference point.


Let's look at a condition where there needs to be "some correlation".
If the polarization of the beam is linear, and using a single LNB dish, one could use the two axis adjustments and have the dish centered on the target SAT, "but"still have the LNB caulked off axis of the linear beam. If there was a tilt adjustment, you could compensate, but if you don't have one, the the mast/dish/LNB must be "plumb" for the LNB antenna to be inline/phased with the SAT beam polarization.
This isn't needed with a circular polarized beam. 101,110,119, & 99/103 are circular, so "tilt" is only to align the LNBs to the arc of the SAT spread.
From reading the forums, the 95 SAT uses linear polarization. This may be the source of the "plumb mast" requirement.


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## cartrivision (Jul 25, 2007)

veryoldschool said:


> With three axis adjustments [right/left, up/down, & right/left rotation], one could mount a dish upside down or sideways and if they didn't run out of adjustments, could align the dish.
> Let's look at a condition where there needs to be "some correlation".
> If the polarization of the beam is linear, and using a single LNB dish, one could use the two axis adjustments and have the dish centered on the target SAT, "but"still have the LNB caulked off axis of the linear beam. If there was a tilt adjustment, you could compensate, but if you don't have one, the the mast/dish/LNB must be "plumb" for the LNB antenna to be inline/phased with the SAT beam polarization.


That's correct. I believe that's why DirecTV chose to use circular polarization instead of verticle/horizontal polarization... because it allowed the old single LNB dishes to be aimed without having to have a skew adjustment on the dish mount.



veryoldschool said:


> This isn't needed with a circular polarized beam. 101,110,119, & 99/103 are circular, so "tilt" is only to align the LNBs to the arc of the SAT spread.
> From reading the forums, the 95 SAT uses linear polarization. This may be the source of the "plumb mast" requirement.


That's not completely correct. An out of plumb mast doesn't prevent you from getting the correct skew. Even with a severely out of plumb mast, once the center LNB is aimed directly at the 101 satellite the dish mount skew adjustment will still rotate all the other LNBs while leaving the center LNB locked on the 101 satellite, so it's just the same as with a plumb pole... the dish has to be rotated on the skew axis until the arc of the LNBs lines up with the arc of the satellites.

After that skew alignment has been done (and it can be done regardless of whether the pole was plumb or not), then any LNBs that depends upon horizontal/vertical polarization will be correctly oriented to the satellite, but as you pointed out, the skew adjustment would still be necessary to align the arc of the LNBs parallel to the arc of the satellites, even if there are no h/v polarized satellites. The only thing that isn't absolutely necessary is a plumb pole (while recognizing the fact that the rough numerical settings for AZ, EL, and Skew are calculated for and only valid for a plumb pole, but also while recognizing that the "correct" numerical settings could be also calculated for any out of plumb pole based on the additional parameters of how many degrees it was out of plumb and in what direction).


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## veryoldschool (Dec 10, 2006)

cartrivision said:


> Quote:
> Originally Posted by *veryoldschool*
> _"This isn't needed with a circular polarized beam. 101,110,119, & 99/103 are circular, so "tilt" is only to align the LNBs to the arc of the SAT spread.
> From reading the forums, the 95 SAT uses linear polarization. This may be the source of the "plumb mast" requirement."_
> ...


 What I said is "completely correct", and you seem to have said the same thing in your "correction". 
Now as for your last part: I don't know if the single LNB dish for the 95 SAT has a tilt adjustment. If it does then "sure", but if it is like the single LNB dish for 101, then it doesn't.


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## cartrivision (Jul 25, 2007)

veryoldschool said:


> What I said is "completely correct", and you seem to have said the same thing in your "correction".
> Now as for your last part: I don't know if the single LNB dish for the 95 SAT has a tilt adjustment. If it does then "sure", but if it is like the single LNB dish for 101, then it doesn't.


What wasn't "completely correct" was your statement that a plumb mast might be required for the skew adjustment to work correctly for aligning the dish for any satellites that use horizontal/vertical polarization.

That's not correct. Even if the mast is significantly out of plumb, once dish is adjusted so that the 101 LNB is pointing at the 101 satellite, then the skew adjustment will rotate the dish about an axis centered on the 101 satellite and LNB, and then with that established, adjusting the skew so that the arc of the LNBs is parallel to the arc of the satellites will also give you the correct orientation for any satellites using H/V polarization... regardless if the mast is plumb or not.


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## veryoldschool (Dec 10, 2006)

cartrivision said:


> What wasn't "completely correct" was your statement that a plumb mast might be required for the skew adjustment to work correctly for aligning the dish for any satellites that use horizontal/vertical polarization.
> 
> That's not correct. Even if the mast is significantly out of plumb, once dish is adjusted so that the 101 LNB is pointing at the 101 satellite, then the skew adjustment will rotate the dish about an axis centered on the 101 satellite and LNB, and then with that established, adjusting the skew so that the arc of the LNBs is parallel to the arc of the satellites will also give you the correct orientation for any satellites using H/V polarization... regardless if the mast is plumb or not.


[last round] "What I said was": if there wasn't a tilt/skew adjustment, like the 18" round single LNB dish.

And with this "I give up" :nono:


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## cartrivision (Jul 25, 2007)

veryoldschool said:


> [last round] "What I said was": if there wasn't a tilt/skew adjustment, like the 18" round single LNB dish.
> 
> And with this "I give up" :nono:


That might be wise, because what you said was this ....



veryoldschool said:


> From reading the forums, the 95 SAT uses linear polarization. This may be the source of the "plumb mast" requirement.


The last sentence of that statement is what was incorrect.

As I pointed out, the tilt adjustment does not depend upon the orientation of the mast for it to work. Once the dish is centered/pointing at the 101 satellite, regardless of whether or not the mast is plumb, the skew adjustment will still rotate the dish about the axis of the vector that points to the 101 satellite, which is all that is required line up the other LNBs with the arc of the satellites, which is also what will provide the correct polarization alignment if any of the satellites are using linear polarization.


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## sstv (Jul 30, 2006)

Hi All
This has gone on long enough.
MODS, PLEASE CLOSE THIS POST
Thanks 
SSTV


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## Tom Robertson (Nov 15, 2005)

At the request of the thread starter, this circular logic has been closed.


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