# OTA, Satellite and Backfeed on single cable?



## Don_S (Jul 5, 2005)

My current setup is a single coax cable carrying the satellite feed TO the 942 and the TV2 backfeed FROM the 942. I am using a Diplexer and Separator on the 942 end of the cable and another Diplexer on the other end of the cable to "jump" the backfeed signal to another coax cable going to the bedroom. Is it possible to inject an OTA signal into the single cable going to the 942? If yes, how would I go about doing it? is it possible to use another diplexer or spliiter on each end of the cable to achieve this? TIA for your replies. 
P.S. Running another cable to the 942 is not an option.


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## robo45h (Jul 8, 2003)

Wow, no response yet. I'm planning on getting a 942 (or 962 if it's coming soon) and will need the answer to this exact question. Which means there are a lot more people in (or soon to be in) the same position. This will be a common question...


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## ThomasTrain (Aug 9, 2005)

Actaully, yes you can as I am currently doing it. Basically you need a 2 way splitter at both ends of the UHF/VHF side of your diplexer. One side on both ends for the OTA feed and the other side for the Backfeed. It's ugly but it works.


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## Don_S (Jul 5, 2005)

Thank you for the response... I am glad to hear that what I had in mind is possible and has been successfully done! A couple of additional questions for you..

1. Will any ordinary 2-way spliiter work or do you need a special splitter with specific frequency responses?
2. Have you noticed any degradation in picture quality due to the insertion loss from the numerous pieces along the signal path due to the splitter/diplexer/separator combination?


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## ThomasTrain (Aug 9, 2005)

1) Yes, just an ordinary cheapie two way splitter is what you need.

2) Yes, due to the signal being split you will experience some signal degradation .

Most two way splitters have 3.5db loss at each split so you can figure that we are losing a total of 7db on the backfeed to your distribution point. But if you factor in the diplexors as well I would think it is somewhere about 15db (I don't know the rated signal loss with diplexors). But From the backfeed I am then going into a 4 way splitter (my distribution) which loses another 7db. So in total I am probably losing around 22db by the time it reaches the TV's but the signal off the tuner 2 backfeed still looks good. 

I figure that since the tuner 2 output is modulated at about 10db higher than a normal signal, I am actually only losing about 12db which isn't bad really.

(Please keep in mind this is all *my* best guess with the signal loss, I am not an expert)


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## Don_S (Jul 5, 2005)

Thanks again. Your response has been most helpful. Theoretical numbers aside, are you happy with the picture quality on the backfed TVs and the OTA picture quality on your primary TV?


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## ThomasTrain (Aug 9, 2005)

Don_S said:


> Thanks again. Your response has been most helpful. Theoretical numbers aside, are you happy with the picture quality on the backfed TVs and the OTA picture quality on your primary TV?


Picture quality on the backfeed TVs is good but of course it would be better with a direct connect receiver.

OTA quality on the primary TV is excellent as well as sat quality since I am using the HDMI-DVI interface. My only problem with my OTA is that I am on the fringe of my broadcasters digital signals but the channels I do pick up are excellent.


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