# Combiner/Splitter Question



## Gremraf (Jun 30, 2006)

I have a combiner that takes my OTA signal and a modulated TV2 output from my VIP 722 unit. Each one gives a perfect signal when sent to the TV direct. When combined the Sat picture is wavy, but the OTA pic is still great. Do I need a better combiner, or a filter. Will see what combiner I have as soon as I can get back in the attic.


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## garys (Nov 4, 2005)

The type of signal may not be set right on your receiver, should be set to analog or there may be interference on the channel your sat signal is assigned to, you might try a different channel number.


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## Gremraf (Jun 30, 2006)

Have tried all the open channels, and so did a dish tech. He thinks I need a new combiner, but hate to just keep buying them till I find one. So any recommendations on a quality unit would be great.


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## harsh (Jun 15, 2003)

Gremraf said:


> Have tried all the open channels, and so did a dish tech. He thinks I need a new combiner, but hate to just keep buying them till I find one. So any recommendations on a quality unit would be great.


Chances are that the device is not a splitter. Maybe it is a separator or a diplexer.

This could also indicate and problem with grounding of your antenna.

Is this OTA signal really from an antenna, or are you trying to fold in a CATV signal?

[strike]Did you try modulating the TV2 output to substantially different channels?[/strike]


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## Gremraf (Jun 30, 2006)

Yes it is a true combiner/splitter has [in/out] on all 3 connectors. Comes from a OTA in attic. Have tried all open channels from 21 to 69.

Never been told to ground the antenna before. Sat is grounded to water pipe outside the house.

Went in the attic. unit is a "DC-2" splitter S1000 Mhz all port DC passice 3.7 DB


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## scooper (Apr 22, 2002)

How about this - post a list of ALL (analog AND digital) RF channels actually in use in your area. Next, for this to work - you need to have a "hole" of 3 unused channels, preferably more, you put the modulated channel in the middle.


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## harsh (Jun 15, 2003)

Gremraf said:


> Never been told to ground the antenna before.


Just as your dish and satellite cables should be grounded, so should your antenna boom and OTA cable. The specifications are in NEC 810.


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## garys (Nov 4, 2005)

Gremraf said:


> Yes it is a true combiner/splitter has [in/out] on all 3 connectors. Comes from a OTA in attic. Have tried all open channels from 21 to 69.
> 
> Never been told to ground the antenna before. Sat is grounded to water pipe outside the house.
> 
> Went in the attic. unit is a "DC-2" splitter S1000 Mhz all port DC passice 3.7 DB


Description also applied to a duplexer, best to double check what the piece of equipment states.


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## oljim (Aug 6, 2002)

harsh said:


> Just as your dish and satellite cables should be grounded, so should your antenna boom and OTA cable. The specifications are in NEC 810.


Why worry about a ground on an attic antenna.


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## harsh (Jun 15, 2003)

oljim said:


> Why worry about a ground on an attic antenna.


Because most modern houses have electrical wiring in the attic?


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## oljim (Aug 6, 2002)

I have electrictal wiring in my bedroom but do not ground my bed


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## Gremraf (Jun 30, 2006)

I have several diplexers laying around so I know the difference between splitter/combiner and diplexers. I will look into grounding the antenna. 
Have not had time to get a complete list of channels available yet.


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## Stewart Vernon (Jan 7, 2005)

oljim said:


> I have electrictal wiring in my bedroom but do not ground my bed


Is it an electric bed?


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## fredinva (May 10, 2006)

Gremraf said:


> I have several diplexers laying around so I know the difference between splitter/combiner and diplexers. I will look into grounding the antenna.
> Have not had time to get a complete list of channels available yet.


grounding antenna prolly won't help.

replace the splitter

fred


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## Gremraf (Jun 30, 2006)

so recommendations on a quality splitter please


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## Gremraf (Jun 30, 2006)

So nobody has a splitter/combiner that they like, or install on a regular basis


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## slowmo (Sep 22, 2006)

You might need a low-pass filter to block off a range of channels in which your modulated TV2 channel(s) can be inserted.

I'm in the process of trying to work this out as well. I have great TV2 reception until I combine my OTA signal (either via a Super Home Node or just a quality splitter).

I found a discussion in avsforum on the super home node for which a poster subsequently added a Channel Plus Low-Pass Filter (LPF-750) which blocked OTA channels 65-69 for use of the modulated TV2 signal(s). Absent the filter, I think you will have too much interference no matter how much you play around with different channel settings for your TV2 modulation.


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## Gremraf (Jun 30, 2006)

Cool,

Let me know if that does it.


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## bnewt (Oct 2, 2003)

I can't remember the name of the unit that I used. It was similar to the super home node mentioned above. It combines my ota & modulated signal from tv2 of my 625 & feeds 5 tv's. Each tv can watch the ota stations or the satellite programming. Works great. There are 2 different versions. One to feed up to 4 individual tv's or the one I used, feeds up to 8 tv's.


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## Gremraf (Jun 30, 2006)

Is the Channel plus cpnf-469, the filter your talking about.


I have no channels in the 14 to 19 range, and only one in the 64-70 range and don't watch it, so does anyone see why this would not work.


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## slowmo (Sep 22, 2006)

That's a notch filter; similar but a little different only with respect to where the blocked channels reside in the overall range for either OTA or cable. With the low-pass filter, all are blocked over a certain range. With the notch filter, channels above and below the blocked range are passed.

You just need to compare your desired OTA channels with the modulation range allowed for TV2 and pick the appropriate filter.

Refer to the site below for specific descriptions (i.e. specific channels blocked) for each filter choice from Channel Plus.

I just ordered mine from Beach Audio. I will let you know if it improves my combining.

http://www.channelplus.com/products_rf.html


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## Gremraf (Jun 30, 2006)

So this is what i would use if none of the channels above 60 are ones i want to watch?

http://www.channelplus.com/product_detail.php?productId=67


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## slowmo (Sep 22, 2006)

Gremraf said:


> So this is what i would use if none of the channels above 60 are ones i want to watch?
> 
> http://www.channelplus.com/product_detail.php?productId=67


Yep and you'll have room for 1-2 TV2 channels before the 69 cutoff.

That is the filter that I ordered. All of my digital OTA channels are below 60.

There are certainly other Channel plus models and other brands with varying ranges of blocked channels. I had just noticed another poster's success with this particular filter and its specifications work well with my situation.


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## Gremraf (Jun 30, 2006)

When is your filter going to be in?


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## slowmo (Sep 22, 2006)

Should be this week; I just requested normal ground shipping.


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## slowmo (Sep 22, 2006)

Gremraf,

I received the filter and have played around with it this morning. So far, it is not the holy grail. I believe there is some improvement but not substantial. My TV2 reception is still worse after I combine OTA and there is not a huge difference if I use or remove the filter.

Perhaps I am trying too much. I'm backfeeding the TV2 remote control signals, combining TV2 signals from 2 different receivers, and adding OTA. Perhaps I'll find the magic combination but so far the filter has not improved my situation.


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## Gremraf (Jun 30, 2006)

Will you try it without the remote signals and let me know how it does.


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## slowmo (Sep 22, 2006)

Sorry but didn't see this in time. I'm done with my experimentation which was only motivated to provide back-up OTA to the bedroom for those 2am situations when severe weather sirens start blaring and Dish is worthless because the signal is lost.

I've already boxed up the filter so that I can return it.


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## Gremraf (Jun 30, 2006)

anyone have another suggestion what filter to use


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## rodent (Aug 21, 2006)

Gremraf said:


> anyone have another suggestion what filter to use


I've had great luck with the channel master LPF-750, solidsignal.com/prod_display.asp?prod=CPLPF-750. It passes 2-60 and blocks everything above that so I set my TV2 channel to 69 and it works like a charm with my super home node. If you don't care about losing any OTA channels above 60, it really did the trick for me. I send an amplified indoor antenna feed and ViP622 TV2 feed to a super home node for distribution to 3 sets around the house and it works great. It wasn't so great until I added the filter.


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## Gremraf (Jun 30, 2006)

Cool,

Thanks for the info, will try the filter with a splitter/combiner. If that doesn't work will look for a super home node.


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## rodent (Aug 21, 2006)

Gremraf said:


> Cool,
> 
> Thanks for the info, will try the filter with a splitter/combiner. If that doesn't work will look for a super home node.


Yeah, it should work with a split/comb, I haven't tried it but I'm not sure i would need a SHN anymore.


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## DNSFSS (Apr 4, 2008)

Just asking the obvious here: Is the cable in question a high quality (2.25GHz or higher) RG-6? I found that a new cable run with great cable can make drastic improvements. Also, have you tried running the TV2 out from the 722 on the cable side, starting from CH 73 and not using the air side?


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## Bob Ketcham (Jan 2, 2006)

Gremraf said:


> I have a combiner that takes my OTA signal and a modulated TV2 output from my VIP 722 unit. Each one gives a perfect signal when sent to the TV direct. When combined the Sat picture is wavy, but the OTA pic is still great. Do I need a better combiner, or a filter. Will see what combiner I have as soon as I can get back in the attic.


"Wavy" signal can be caused by problems other than adjacent channel interference.

A "herringbone" wave (several lines displaying diagonally) is usually an indication that the channel's input signal to the TV is too strong. If you have an amplifier in the line remove it or lower the gain if it is adjustable.

A single horizontal wave that moves slowly through the screen from top to bottom is usually from 60 cycle electrical interference. If the source of the 60 cycle interference can't be found, it can usually be rendered nearly invisible by adding an amplifier in the line.

If instead of wavy, you meant "snowy" a little bit of amplification could help. I use an RCA amplified splitter DT140M I picked up at Best Buy for about $45. I has a much cleaner signal than the $20 black boxes at Radio Shack, etc.

The comments about making sure it was not a diplexer have been right on target. The IN/OUT label on all three connections is not enough. My diplexers have all three connections labeled in and out. The key for an off-air antenna / UHF TV2 signal splitter / combiner is to make sure that the frequency range is the same for all inputs. That is, the splitter / combiner should not have one input with a high frequency rating that is needed to pass the satellite signal.

My setup has two VIP622 DVRs each directly connected to a TV1. The modulated TV1 and TV2 channels on each DVR are set to 4 different unoccupied UHF channels and the outputs are combined with my off-air antenna signal before being boosted / split to 4 other remote TVs. Any DVR can be watched from any remote TV. I have accumulated enough UHF pro remotes over the years to support this setup.

I am using an "IDEAL" brand splitter I bought a the local Electronics Parts Outlet (the store's name) to combine the modulated DVR signals and the broadcast antenna signal. The splitter is likely surplus overstock material they acquired somewhere. It is rated 5Mhz to 2.3Ghz. It is a bit sturdier than the tin boxes you find at most stores.

It took a while to get the picture "right" on all sets in this setup. Properly shielded connections are important. Initially, I used a single coax from the attic (where the sat switch, antenna, diplexers, splitter/combiners and amps are located). Putting the modulated TV2 signal back up the line with the off-air and sat signal coming to the DVR worked, but did not work well. So each DVR now has two coaxes from the attic (one up, one down).

The most distant DVR signal (longest cable run) is boosted (with an adjustable 10-20db black box amp) before combining with the other DVR and the off-air antenna signal. The antenna signal is boosted and split with an RCA box then sent to the DVRs or combined with the modulated UHF signals from the DVRs. The combined off-air and DVR UHF signals are again boosted and split with another RCA box then sent to the remote sets. Note that the signal sent to the DVRs is a combination of off-air antenna and Sat switch signal. It does not contain any modulated DVR signal being sent back down the line.

A good site to use to make sure the UHF channels you are using are not on or adjacent to occupied channels is antennaweb.org

Sorry if this is TMI. It looked like most of the answers you have so far have too little.


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## Bob Ketcham (Jan 2, 2006)

Gremraf said:


> Yes it is a true combiner/splitter has [in/out] on all 3 connectors. Comes from a OTA in attic. Have tried all open channels from 21 to 69.
> 
> Never been told to ground the antenna before. Sat is grounded to water pipe outside the house.
> 
> Went in the attic. unit is a "DC-2" splitter S1000 Mhz all port DC passice 3.7 DB


Re: have tried all open channels from 21 to 69.

It is important to use a really empty channel. If your local stations have begun digital broadcasts, they are likely using UHF frequencies. For example digital channel 11.1 here is actually using the UHF frequency formerly called channel 31. No picture shows up on an analog TV, but the signal will sure interfere with a TV2 modulator if it is set to channels 30, 31 or 32.

The listing of channels in your area that can be generated from antennaweb.org will show you the old UHF channels occupied by new DTV signals. Use it to pick the best channels to use for remote TV signals.


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## Bob Ketcham (Jan 2, 2006)

slowmo said:


> Gremraf,
> 
> I received the filter and have played around with it this morning. So far, it is not the holy grail. I believe there is some improvement but not substantial. My TV2 reception is still worse after I combine OTA and there is not a huge difference if I use or remove the filter.
> 
> Perhaps I am trying too much. I'm backfeeding the TV2 remote control signals, combining TV2 signals from 2 different receivers, and adding OTA. Perhaps I'll find the magic combination but so far the filter has not improved my situation.


RE: perhaps I am trying too much.

You may be. As I said in the note above, putting sat, off-air and TV2 UHF signal all on one wire did not work well for me. In the end I went to two coaxes for each DVR. One to the DVR with off-air and sat. One from the DVR with TV2 UHF signal.

I think the primary problem with one coax was in combining TV2 UHF signal with off-air signal then sending it back down the DVR cable from where it came. It interfered with itself. A single coax worked, but signal was visibly cleaner with separate coaxes.


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## kucharsk (Sep 20, 2006)

Are you using the attenuator that DISH now provides for use on the RF output to avoid overpowering your equipment on "short" cable runs?


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## 4HiMarks (Jan 21, 2004)

Bob Ketcham said:


> RE: perhaps I am trying too much.
> 
> You may be. As I said in the note above, putting sat, off-air and TV2 UHF signal all on one wire did not work well for me. In the end I went to two coaxes for each DVR. One to the DVR with off-air and sat. One from the DVR with TV2 UHF signal.
> 
> I think the primary problem with one coax was in combining TV2 UHF signal with off-air signal then sending it back down the DVR cable from where it came. It interfered with itself. A single coax worked, but signal was visibly cleaner with separate coaxes.


PMBI, but it sounds like you are doing something like what I am trying to do. A 622 has 2 sat inputs though. Shouldn't you need three coaxes (2 sat/OTA in and one TV2 back out)? Where does the TV2 signal from the other 622 fit?

-Chris


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## harsh (Jun 15, 2003)

4HiMarks said:


> Shouldn't you need three coaxes (2 sat/OTA in and one TV2 back out)? Where does the TV2 signal from the other 622 fit?


You only need one satellite cable for the ViP622 if you have a modern dish or switch.


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## Gremraf (Jun 30, 2006)

I have 1 coax for sat, and 1 for locals from OTA to both the 722 and the 622. Problem is with TV in bedroom, cannot replace coax in that room without taking sheetrock off the wall. Not using attenuator, or amplifier on any coax at this time. All Coax is RG6, or RG6 Quad.


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## Bob Ketcham (Jan 2, 2006)

4HiMarks said:


> PMBI, but it sounds like you are doing something like what I am trying to do. A 622 has 2 sat inputs though. Shouldn't you need three coaxes (2 sat/OTA in and one TV2 back out)? Where does the TV2 signal from the other 622 fit?
> 
> -Chris


Chris,

Re: A 622 has 2 sat inputs though. 
Dish provided a SAT1 / SAT2 splitter for the back of the DVR with the 622.

Re: Shouldn't you need three coaxes (2 sat/OTA in and one TV2 back out)?
The Sat / OTA In coax can contain both Sat and OTA in one coax. Sat signals are at a higher frequency than the TV OTA signals. The diplexer (looks just like a 2 input, 1 output splitter / combiner) has one IN/OUT connection for the SAT signal and one for the OTA signal. The diplexer can be identified by the labels showing higher frequencies on one in/out connections and lower frequencies on the other. One diplexer is used in the attic to combine the signals and another at the back of the DVR to split them. Then the dish provided SAT splitter splits the SAT1 and SAT 2 signals.

RE: Where does the TV2 signal from the other 622 fit?
Both 622 TV2 signals are sent to the attic on their dedicated coaxes. In the attic they are combined with the OTA signal. The OTA signal has already been boosted and split using an RCA DM140. The combining is done in the IDEAL 3 In / 1 Out splitter combiner mentioned in the prior message. The combined signal is then boosted and split by another DM 140 and sent to the four remote TVs.


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## Bob Ketcham (Jan 2, 2006)

Gremraf said:


> I have 1 coax for sat, and 1 for locals from OTA to both the 722 and the 622. Problem is with TV in bedroom, cannot replace coax in that room without taking sheetrock off the wall. Not using attenuator, or amplifier on any coax at this time. All Coax is RG6, or RG6 Quad.


Need a little more detail... 
Which of the two coaxes contains the TV2 signal?

As my prior note indicates, I combine the SAT and OTA on one coax to the DVR and return the TV2 signal to the attic with the second coax. I think this is optimum, but does require use of the SAT/OTA diplexers. There are other ways it could be done, but I don't think it will work well if you try to send the TV2 signal out on the cable bringing the OTA to the DVR.

If the TV in the bedroom is a remote TV, it only needs one coax.

Depending on the length of the run you may need an attenuator (short run) or an amp (long run).

But, first I would make sure that the TV2 signal is not on the same cable bringing OTA to the DVR.

If the TV in the bedroom is not a remote TV, but is a DVR, suggest testing solutions I have suggested using the DVR where you have two cables and see if it fixes the problem. Then decide if you need to pull the second cable to the bedroom.


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## Gremraf (Jun 30, 2006)

Sat and ota are diplexed together, tv2 is on single coax out


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