# LNB Drift Detected??



## jgurley (Feb 1, 2005)

I have ver. 4.03 and ran System Info. last night and got a warning "LNB Drift Detected". The details read 0x0e, 0xa1, 129(e-7.45) 0o.00

Can someone tell me what the e-7.45 means? I'm assuming that the "e" likely means elevation.

Thanks


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## putabengali (Apr 28, 2007)

drift is a poor choice in wording, but what it's detecting is the likelihood that the lnb will fail in the near future. Anything less than -8 or more than 8 requires a service call to replace lnb. The good news is that dish just launched the "LNB DRFIT SERVICE CALL" which is free regardless of warranty status. So if the number currently saying 129(e-7.45) goes to 129(e-8.00) or anything lower, call dish and get your free replacement


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## putabengali (Apr 28, 2007)

jgurley said:


> I have ver. 4.03 and ran System Info. last night and got a warning "LNB Drift Detected". The details read 0x0e, 0xa1, 129(e-7.45) 0o.00
> 
> Can someone tell me what the e-7.45 means? I'm assuming that the "e" likely means elevation.
> 
> Thanks


oh, and 'e' stands for 'even'... as in even numbered transponders


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## jgurley (Feb 1, 2005)

Thanks for the info. Just talked with Tech Support and have a service call scheduled. She said the software is programmed to detect potential problems so they can be fixed before the satellite actually goes down. I'm impressed.


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## BNUMM (Dec 24, 2006)

jgurley said:


> Thanks for the info. Just talked with Tech Support and have a service call scheduled. She said the software is programmed to detect potential problems so they can be fixed before the satellite actually goes down. I'm impressed.


Don't get too excited. I am an installer and I have seen the lnb drift error and the problem was not the lnb. Make sure the problem is fixed be the installer leaves because it may be something else.


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## jgurley (Feb 1, 2005)

Could this "problem" be caused by a tree limb partially blocking 129? I lost all 129 signals when a large tree started sprouting its leaves, cut one large limb and got 129 back with signals better then ever. I was sure I had solved that problem, but now I"m wondering if another limb could still be interfering. I told my wife today I should just go ahead and cut this second limb figuring it may be just a matter of time before it grows into the 129 path. This cutting was done before I checked System Info so I don't know if I was getting the "Drift" message or not.

Mmmmm, I think I should just go ahead and cut the second limb and see what happens. I don't want the Tech to have something to blame this "Drift" message on. What do you think?

P.S. These limbs I'm referring to aren't ones you take off with a lopper. I'm talking about climbing up about 20 feet with a chain saw, the limbs are about 8-10 inches round at that height and 15 to 20 feet long. This is no "girlie" tree!!!


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## P Smith (Jul 25, 2002)

"Drift" values means here changing LNBF's internal oscillator frequency out of normal range ( +- 5 MHz) what can not be or could hardly compensated by satellite tuner circuit.

Any problem with aiming the dish or external blockage stuff DOESN'T affect the drifting report. 
It is LNBF INTERNAL problem. If you exclude SW bug and glitches .


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## BNUMM (Dec 24, 2006)

P Smith said:


> "Drift" values means here changing LNBF's internal oscillator frequency out of normal range ( +- 5 MHz) what can not be or could hardly compensated by satellite tuner circuit.
> 
> Any problem with aiming the dish or external blockage stuff DOESN'T affect the drifting report.
> It is LNBF INTERNAL problem. If you exclude SW bug and glitches .


I have found that the LNB Drift message is not always a problem with the LNB. I have found from experience that it can be caused by a dish out of alignment or possibly a deformed dish.


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## P Smith (Jul 25, 2002)

You found bogus reason unfortunately for you. 
The parameter CANNOT be changed by deforming dish or misalignment. 
There is LO drift
Just for broadening your knowledge in the field, take a pick how the LNBF build in the thread.


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## BNUMM (Dec 24, 2006)

P Smith said:


> You found bogus reason unfortunately for you.
> The parameter CANNOT be changed by deforming dish or misalignment.
> There is LO drift - if you're not RF engineer, then don't make up the arguments.
> Just for broadening your knowledge in the field, take a pick how the LNBF build in the thread.


These are not bogus reasons. They are facts. Every situation where I have seen the LNB drift message the problem has not been the LNB. I remember 3 specific situations. The first thing I tried on each was to replace the LNB. Each time after replacing the LNB I still got the LNB drift message.

Situation 1 was resolved by simply running a check switch. The message has not come back.

Situation 2 was resolved by aligning the dish. The message has not come back.

Situation 3 was resolved by replacing the pan. The message has not come back.

If you don't believe the above that is fine with me. I was only trying to inform people that replcing the LNB may not solve their problem and that if it doesn't then here are a few things to try. These forums are meant to help not to criticize suggestions.


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## P Smith (Jul 25, 2002)

Well, I did my reservation for SW bugs, errors; 
but misalignment, damaged pan - sorry I can't take the points as EE (plus considering my SW/HW years experience). 
Perhaps SW so baldy written and LNBF reporting bogus info ... Then I don't understand the whole idea what Dish try to implement. 
Wrong input ( garbage in ) cannot be processed for make good decision. 

Whole picture will be totally stupid if your observation have merits.


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## kmcnamara (Jan 30, 2004)

P Smith said:


> Well, I did my reservation for SW bugs, errors;
> but misalignment, damaged pan - sorry I can't take the points as EE (plus considering my SW/HW years experience).
> Perhaps SW so baldy written and LNBF reporting bogus info ... Then I don't understand the whole idea what Dish try to implement.
> Wrong input ( garbage in ) cannot be processed for make good decision.
> ...


Here's to you Mr. Awesomest Engineer Ever. 

The guy makes some valid points of things he's observed and you effectively tell him he has no idea what he's talking about (at least I _think_ that's what you said). You need to get off your high horse.


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## BNUMM (Dec 24, 2006)

Maybe I should avoid posting any of my troubleshooting experiences. Apparently I am too stupid to post here. I could post my background, education and experience but that would be pointless as I have always fixed the problem.


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## Ron Barry (Dec 10, 2002)

Ok.. lets watch the personal insults. it is unnecessary and does not add value here. 

We are all here to help and to offer our own experiences. It is ok to have different viewpoints and to disagree but lets try and avoid the insults. I have edited a few of the the less friendly remarks from the posts above. 

I plan on adding this to the Tips and Tricks thread so lets keep things rolling and on a constructive road.

And I believe P. Smith's (if I am reading it write) stupid comment was regarding that if your observations are accurate then the reporting mechanism is flawed. I don't think he was calling you stupid. If he does correct me on this point, I will remove the comment but I don't think that was the intention. 

Opinions are always welcome here especially experiences from the field. Just because something does not make sense does not necessarily make it not accurate. And yes.. The main purpose of these forums are for helping and I all input is welcome.


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## P Smith (Jul 25, 2002)

Sorry for drifting the discussion to personal aspects - it WASN'T my intention; I did attempt to stay with real physics, not who did that.

I would rather have a conversation how this diagnostics works and what factors contribute to the issue.
But, we fall into discussion about different points.

Want to add my [personal] vision of the discussion ( actually, why I mentioned RF engineer level ) - let me do it little easy - imagine you're auto mechanic ( I think any man should feel he knows everything about car's guts  ) and other person telling you: that engine sporadically revving, black smoke coming out, etc BUT if you cleaned windshield or after you did wheels alignment the symptoms goes away. What you'll say ?

I expected little higher professional level talk of the issue.


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## jgurley (Feb 1, 2005)

I guess it's time I jumped back in here since I started this discussion. For me putabengali's posts on 4/30 was most helpful. 

When I called tech support the CR knew exactly what I was talking about and immediately scheduled a service for tomorrow afternoon. I received a call from my local Dish service company yesterday for confirmation and I asked him if he had dealt with this issue before and he too knew about the problem. He said the LNB needed replacing. 

Of course the only question I have today is if the techs they send out also know what they're doing. I'll just wait and see and let you guys know what happened.


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## jgurley (Feb 1, 2005)

Here's an interim report. I cut that other limb I referred to earlier and can see no change. Still getting the lnb drift message and my signals on sat. 129 are low of 62 (tp22), the rest ranging from 68-89 depending on the TP. Based on the info I have in this area those are quite good so my dish is most likely aimed properly.


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## boylehome (Jul 16, 2004)

I have LNBF drift on one LNBF used for 110 satellite. This LNBF connects to a DPP44. The ViP622 detects the drift at is -5.83e.

I took a good LNBF and swapped it with the reported drift LNBF.

After making the change, I checked the system information again. Hmmm, same drift reported for the 110 satellite LNBF. I swapped cabling. No difference.

The only thing I can figure is that it is a reporting error, or there is something internally wrong with the fairly new DPP44. 

In conclusion, there is nothing wrong with either LNBF that show drift.

UPDATE: I swapped the cables connected from the LNBF's to the ports on the DPP44 switch for 119 and 110. I ran a check switch. Once the receiver was normally operating, I checked System Info. No more LNB drift. Status is, "Good" and green colored. The problem may be switch related. The cable swap and check switch cleared the problem. Also, before testing today, I had performed check switches but LNB drift was detected.


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## ezra (Mar 10, 2007)

I had previously answered what lnbf drift was in a prev post about a month ago... however it is now E* policy to replace lnbs with drift valuse above +/- 8 for even or odd transponders free of charge to the customer.. I have also read some of P Smith's previous post and found them to be insightfull, however, BNUMM I correct about lnbf drift not always being an lnb issue as i have RA'd several thath have resulted in no problem founds... and the csut still kept calling back... in these cases i found the dishes were replaced, switches were replaced, etc, etc , until the customers intermiten signal loss was corrected.... now why would lnb drift not be caused by an internal failing of the lnbf... i have pondered that question and experimented to find my own answer... I have found that a warped dish can recreate the drift phenomenon and why.... when i was in the army setting up my uplinks i screwed up one time on one of my dish plates... my CO was not too happy cause i could not for the life of me figure out why i had such a dirty signal... all connectiosn were ok, all equipment was ok but the spectrum analyzer showed up a horrid wave form.... then i looked over my dish and 'fixed' one of my dish plates and voila a beautifull wave appeared....it was simply the destructive interferece patern created by at slight .035 degree offset on one of my dish plates.... I believe the same holds true for a 20" dish that is not necesarily made to the best of grades and lnbs that are cheaply cast and quickly assembled in many different assembly areas...I dont believe this forum was created with the intent or purpose of having its members write up detailed equations to support their finding or having to post pictures of their spectrum analyzers. This forum is for helping others and nothing beats personal experiece because in the field all the equations or procedures meant nothing if we could not get the link up... as to the car analogy: drift would best be explained as a point at witch the resonating frequency of the individual intake runners creates turbulence with in the plenum due to inconsistencies in volume/shape or location resulting in an uneven distribution of air mass/volume per cylinder yeilding uneven power ouput per cylinder creating uneven stresses in the reciprocationg assembly leading to vibrations witch over time lead to premature decay in the main bearing/ rod bearing and premature engine failure as the ocilating frequency of the engine changes due to small imperfetions...I learned this after losing a few blocks at the track go figure.... ITBs is how i race now... also do chech in to the tech portal at dish network. the lnb drift can be found under receiver/ receiver model #. then select symptoms and go under signal loss, intermitten... follow the tshooting steps and step 3 askes if you hgave the chech details for lnb message on your sytem info screen and explains what the values of lnb drift mean....

thanks for your time and patience...


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## BNUMM (Dec 24, 2006)

I am glad you confirmed that one problem could be a deformed dish. I am still confused as to why a check switch being performed would correct the problem.


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## P Smith (Jul 25, 2002)

Oh! That's explain .
"drift would best be explained as a point at witch the resonating frequency of the individual intake runners creates turbulence with in the plenum due to inconsistencies in volume/shape or location resulting in an uneven distribution of air mass/volume per cylinder yeilding uneven power ouput per cylinder creating uneven stresses in the reciprocationg assembly leading to vibrations witch over time lead to premature decay in the main bearing/ rod bearing and premature engine failure as the ocilating frequency of the engine changes due to small imperfetions..."
To someone  - I'm too old to swallow this 'soup' .

Show me how big should be dent for affect 12 GHz signal what will deform one tpn range ( 27 or 36 MHz ) that way when IRD will treat it as shifted median frequency for more then +-5 Mhz. We are talking now about SHIFTING input signal in range 12.2-12.7 Ghz. Ahhh, nevermind.


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## ezra (Mar 10, 2007)

Now shifting is a whole new can of worms but i figured you might get a good laugh at my engine analogy  I really lost several motors due to freak freq interference issues in my intakes and wife was not happy  but i survived... now if you would like to play with lnbf drift you can mod your lnbf by removing the cover and changing the symetrical intake of the lnb to distort the wave collected and create turbulace... had this buddy had a call from one guy who had the drift issue and is was actully due to some bees that had gotten inside his lnb and were really messing things up for him... guy had to pay for lnb as insects are not covered under dhpp.. also P smith lets look at some stats here dish has over 13.3 million c\ustomers * varying ages of dishes */varying ages of lnbs and * the weather * manufacturing conditions/quality * a relative chaos element you get some weird results... one of them happens to be the lnb drift phenomenon and i call it the wobble/ woble sp?... it does not happen very often mathematicly (yeah right!) but in the real world where i work and live stuff happens all the time that jsut doesnt follow all those nice logical rules that we like to call physics or maxwells equations hence we have quatum theory/mechanics/ stuff like electrons tunneling when they should not be able too... etc etc so bro dont worry jsut join me one of these and take call "helping" cust all day with these types of issues and then see if all those laws really mean anything in the real world... As my Intergrated circuits profesor said " electrons don't ever play fair in the realworld, remeber they are the biggest cheaters of them all" 
so I cheat right bvack at em 

Now as to the switch issue i believe that has to due with E* engineering desing or lack of that does not terminate unused outputs... when i setup my uplinks I always terminated any unused trucks beacuse they could casue this freak rearfaction (sp?) you know the decompression wave effect taht would dirty up the signal and the modems/ upconverters didnt want/like dirty signals... also I have another theory that may sound totally bogus to you bro but hear/read me out.. eh heh he ..i have tested this at work and it works... usually with lnb drift or intermiten signal loss i have the cust unplug the lnb cable(sat in cable on the receiver) and if there are no other receivers connected i have them touch the copper wire inside the coax with their thumb/ key to the metal head... why do this to reset the lnb and short out/ discharge any capacitance that may have accumulated on the cable over time and the lnb... now how can the cable rated at 75 Ohms build capacitance if it is grounded... well my money is on it not being properly grounded and have you ever ohmed out a grounding block on mine i got 80k ohms yeah that doesn't cut it for me because im sure you know r-c circuits and that there is what i believe truly causes most of the customers no signal/ signal loss issues... go ahead and hook up an ammeter inline with your sat coax and observe the amperage traveling over that cable and if you have a dvr you know that thing runs none stop for ever and ever so in equation world all the currents equal to 0 if we do our circuit analysis but in the real world electrons cheat all the time so we get leaks and sometimes due to wind friction we get static build up on the dish (lord forbid they cheat there too) and well in theory all these electrons would play nice but they cheat so we get hired and have jobs as techs to help people tshoot their problems... now both you (P Smith) and i know that the carrier wave is the most important as the data has been modulated into it and we need to extract it by locking on to it and demodulating out data out of it... if the lnb is drifting it means ( now seriously in my tech opinion) that the wave coming into the lnb wave guide is dirty and the lnb can not clean up the wave to the point where the carrier can have its data extracted within the error correcting capacities of the dbs sytem (my army setup used 3/4 foward error correction) E* i dont know... now 2: the lnb circuits have begun to degrade and noise with in the lnb circuit is actually adding to the difficulty of locking onto the carrier resulting in poor data extraction(intermiten signal loss). 3 an external element has caused disruption/damage to the lnb circuit adding noise to the circuit and leading to lnb failure. Now i dont know if you have ever taken an lnb apart i dismembered a twin dp pro just to look at the wave guide paths and how the circuit looked... now these circuits are by nature/design supposed to be extremely sensitive to rf signals and this sensitivity is what makes them fragile to external variables from their own system (grounding block, switches, dpp seperators (hate these things), diplexers (hate these too)) now all these components have a grouding screw if you look at them and its beacuse every single one of these components can have an adverse effect on your reciver/ switch/ lnb/ signal.... Hew! im tirred and i have to go to work tomorrow again Doh! hope this helps clear up how the drift phenomenon comes about and yes this is my personal theory and i am willing to bet $25 taht if we hook up a spectrum analyzer to one of these drift lnbs-receiver-systems in action or should i say nonaction Im right... he he he and no Im not done yet but this is where i got to stop for now... good night guys.. I put up with enough at work i dont want to see what i deal with at work here. I like to enjoy my time at this forum and help my fellow intellegent man/ er woman too. thanks guys...


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## P Smith (Jul 25, 2002)

Call me next time when you will slip umm drift  into the issue - I'll bring my SA.

Oh, forgot to tell you - follow yellow brick road  - um, that URL in post#9


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## James Long (Apr 17, 2003)

It seems that even after Ron's warning this thread is drifting.

Keep the posts related to the ViP-622 DVR please.


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## jgurley (Feb 1, 2005)

The Tech just left and I still have the LNB Drift message. In order: he ran check switch, did a hard reboot, replaced the LNB, checked and made slight aim adjustment to the dish. I should mention that he had never encountered this "problem" before.

During the week I checked the Drift Message at least a couple of times each day, and it reported in the range of -6.45 to -8.60, most were about -7.50. This morning it was -6.45 (the lowest it's been all week) and that's what it was just before and after the LNB was changed. 

The only thing left to do is the replace the dish and tech support wasn't willing to do that at this time (yes, I had them on the phone), especially since the current reading is within the tolerance range. 

My thinking is they did all that could reasonably be done at this time. I'll keep a watch on this drift message issue and see what happens. If it does go up consistently then I'll be calling tech support. Until then all else seems well, but I'd appreciate any advice.

This has been quite an interesting thread.


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## P Smith (Jul 25, 2002)

I would try last approach in SW - clean NRAM. Be aware ALL your settings will gone after that.


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## 4bama (Aug 6, 2006)

More data on LNB drift:

We have a 622 and a 508 DVR. My wife is the primary 508 user. A little over a week ago she complained that randomly the 508 displayed the blue screen saying the "signal has been lost, switch to another channel". (Not satellite signal lost, but channel)

I did a detailed channel survey of the 508 and discovered 25 different channels randomly lost, then locked the signal. All were even transponders on 110 and 119 satellites.

I have had no problems with my 622 but from reading this thread I noticed the 622 can detect LNB drift, so I ran the system info on my 622 and it showed both the 110/119 with LNB drift on even-only transponders. I tracked the values for 3 days and noticed the drift values varied from about -5.5 to -7.2, depending on the outside temperature. Late at night or early morning the drift values were lower, during the early afternoon as temps climbed into the 80's the drift vaules increased toward -7.0.

I called Dish and they sent their tech here to check the 508 problem. I showed him what I'd found using the 622 diagnostics and other info I had from here. He replaced the 110 & 119 LNB's, ran a check switch on the 622 then system info again and everything was good...no more LNB drift error message.

The 508 is now solid again with no random channel signal losses.

Obviously the 622 has a more tolerent tuner, or compensates for LNB drift, while the 508 does not. Even when the drift was -7+ the 622 locked to all channels. BTW, switching channels now on the 622 seems faster.

So even if your 622 has no problems, if your LNB drift indicates +/- 6 or more you may get faster channel changes by replacing the drifting LNB(s).


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## jarvantgroup (Mar 24, 2006)

BNUMM said:


> I am glad you confirmed that one problem could be a deformed dish. I am still confused as to why a check switch being performed would correct the problem.


Supposedly LNB drift is to be corrected by replacing the LNB. I've done that and ended up with the same messages. Went on to use some of the 'bad' LNB's, with no subsequent issues....go figure. I really don't pay much attention to the drift issues anymore. At least until Dish can confirm that simply replacing the LNB will cure potential problems. :icon_cool


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