[outdoors]

I've been trying to puzzle through what the installers of my DircTV (phase III) dish and OTA antenna (CM 4221) did by looking at the wiring in my basement.


I finally think I've figured it out. The DirecTV installer ran 3 RG 6 runs off the roof since I have 3 receivers (I should have explicitly asked for them to run all four... oh well). The antenna installer piggy-backed off one of the RG 6 runs by patching in the OTA signal using a combiner.


So, in the basement I have 3 coax runs connected to a grounding block. 2 runs then connect to the structure wiring in the house. The 3rd run (combined OTA and satellite signal) runs through a diplexer and then connects into the structure wiring.


Based on marginal signal strength on one of the OTA channels I want to amplify the OTA signal after it is separated from the satellite signal. Does this pose any problems since the RG 6 cable combines OTA & satellite upstream?


Are there any better solutions other than completely separating out the satellite and OTA signals on their own runs?

 

[jcm]

You probably realize this already, but yes it is going to result in a stronger signal if you separate out your off-air antenna feed from the satellite lines. The insertion loss of a typical diplexer (the combiner your installer used) is .5 to 1dB, and there are two in your line, one to combine the signal and one to separate it back again. The signal loss in the coax cable itself is considerable as well for UHF channels, 5 to 6dB per 100ft for a decent grade RG-6. If I were running a new cable, and it were for a weak UHF signal, I would consider using RG-11. Its not that much more difficult to work with, and has much less loss for these frequencies.


jcmitch