probs seeing OTA in diplexed configuration

[dubblbubbl]

I was doing a experiment yesterday where I am trying to test my plan of using diplexers to get OTA signal and DISH signal combined on a single coax. In this test I took the sat feed and ran it into the 'sat' terminal on the DPD2 diplexer, and then ran an antenna feed (monoprice HDA-5700) into the 'ant' terminal, then ran a single 6ft cable to the other DPD2 diplexer, then from the 'sat' to the dish receiver (301), and the 'ant' into the hda 5700 amp then into the TV. When I run a scan in this config, Sat feed is good but the TV picks up about 1/3 of the available stations on the ota scan. None of the 2-18 range channels were picked up, and those in the uhf range were weak. When I revert to an undiplexed config, and take the ant signal straight from the antenna to the inserter to the tv, I get everything available.

Everything I've read would indicate that this diplexed config should work fine, so I suspect it's either the cables I was using for the experiment, or the location of the amp. I was using some cables I had laying around in the garage for who knows how long. I did read somewhere that the location of the power inserter can have a bearing on the signal strength, if so where should it be placed? That info just said the inserter was an issue, but not any help on where it should be placed. Any help would be appreciated. Is there something about the dpd2 diplexer that can degrade the ant signal, or could one of the diplexers be bad?

 

[gmcgown]

My Dish reception OTA was just terrrible 30 miles from Broadcast Hill here in the D/FW area...I quit Dish for Directv. My Directv HR23-700 had no provision for the antenna. Plugging the antenna into the back of the TV produced a superb picture on all the digital channels. I think the Dish Receiver/DRV was the cuprit and may be the cause of your difficulties...

 

[gdarwin]

Looks like what you are calling "5700 amp" is the power supply for the antenna. If you can get it on the other side of the diplexors it should work.

 

[dubblbubbl]

Thanks guys

Yep, didn't know what the correct terminology is but, it is referred to as the power supply in the manual for the antenna.

 

[Voyager6]

I was doing a experiment yesterday where I am trying to test my plan of using diplexers to get OTA signal and DISH signal combined on a single coax. In this test I took the sat feed and ran it into the 'sat' terminal on the DPD2 diplexer, and then ran an antenna feed (monoprice HDA-5700) into the 'ant' terminal, then ran a single 6ft cable to the other DPD2 diplexer, then from the 'sat' to the dish receiver (301), and the 'ant' into the hda 5700 amp then into the TV. When I run a scan in this config, Sat feed is good but the TV picks up about 1/3 of the available stations on the ota scan. None of the 2-18 range channels were picked up, and those in the uhf range were weak. When I revert to an undiplexed config, and take the ant signal straight from the antenna to the inserter to the tv, I get everything available.

Everything I've read would indicate that this diplexed config should work fine, so I suspect it's either the cables I was using for the experiment, or the location of the amp. I was using some cables I had laying around in the garage for who knows how long. I did read somewhere that the location of the power inserter can have a bearing on the signal strength, if so where should it be placed? That info just said the inserter was an issue, but not any help on where it should be placed. Any help would be appreciated. Is there something about the dpd2 diplexer that can degrade the ant signal, or could one of the diplexers be bad?

I would attached the amp after the diplexer. That is: TV - diplexer - amp - ant. I don't think that the amp was getting power with your previous order. Also, each addition (i.e. - diplexer, splitter, etc.) adds to signal loss. So running the ant to the TV directly should get you more signal.

 

[GaryPen]

The signal loss from the diplexers alone should be minimal. Holland rates them at 1-1.5dB loss per diplexer.

However, your problem is pretty obviously the loss of DC power from the inserter to the antenna.

I am in the same boat, and have to use a larger non-amplified antenna vs a small amplified model due to my use of diplexers.

 

[dubblbubbl]

success!

Looks like what you are calling "5700 amp" is the power supply for the antenna. If you can get it on the other side of the diplexors it should work.

That was the trick. I moved the power supply to the incoming 'ant' terminal on the upstream diplexer. All channels received now. Thanks for the help. Now all I have to do is get power to the first diplexer when I build all this out in the attic.

So the config I'm going with will be (due to ascii drawing limitations, the single diplexer pair is shown on both paths below):

44 sw. > (sat) >[diplexer a] -------[diplexer b] (sat) > receiver
ant > pwr supp. (ant) > [diplexer a] -------[diplexer b](ant) > TV

 

[gdarwin]

Kool!