Basic Cable, Dish Network, and OTA Antenna

[rockymtnhigh]

Ok, I have an OTA antenna, which I am using in conjunction with my Dish Network system. But I also have basic cable from comcast, which provides unencrypted HD QAM feeds.



I want to be able to add the QAM feed to my primary HDTV. My thought was to see if I could diplex the coax run that currently is limited to the OTA antenna.

Is that possible? Can I combine the comcast and OTA antenna using a diplexer, and then just split it out again at the tv, one going to Dish's Antenna IN, and the other going to the antenna in on the tv?

[RandallA]

"Is that possible? Can I combine the comcast and OTA antenna using a diplexer, and then just split it out again at the tv, one going to Dish's Antenna IN, and the other going to the antenna in on the tv?"

No, it's not possible. A diplexer combines CATV/UHF/VHF and satellite signals. One way to do it is to combine OTA and CATV with a regular splitter and then combine those two with the satellite signal using the diplexer. At the other end you use another diplexer to split the signals and another splitter to split the OTA and CATV.

The problem with that is that your antenna will be broadcasting the CATV channels and AFAI it's illegal to broadcast them. I would just run a second cable but others might have other suggestions like the Super Node or the use of notch filters.

[rockymtnhigh]

Ah... wasn't thinking about it serving as a broadcasting of the signal; was just thinking it was a coax line that I could use.

Obviously I could use that line if I was willing to disable the OTA channels, by disconnecting the antenna's coax, but that was not my goal. Just want to find a way to get the QAM feeds while leaving the Dish stuff alone.

[vegassatellite]

"Is that possible? Can I combine the comcast and OTA antenna using a diplexer, and then just split it out again at the tv, one going to Dish's Antenna IN, and the other going to the antenna in on the tv?"

No, it's not possible. A diplexer combines CATV/UHF/VHF and satellite signals. One way to do it is to combine OTA and CATV with a regular splitter and then combine those two with the satellite signal using the diplexer. At the other end you use another diplexer to split the signals and another splitter to split the OTA and CATV.

The problem with that is that your antenna will be broadcasting the CATV channels and AFAI it's illegal to broadcast them. I would just run a second cable but others might have other suggestions like the Super Node or the use of notch filters.

This arrangement wouldn't create a broadcast of cable signals since they are flowing in the same direction as the OTA signals towards the box. Splitters usually have high RF Isolation between OUT ports so the cable signals wouldn't be flowing from the OUT port where they are being fed in to over to the OUT port where the OTA is being fed in to.

I think his biggest problem with doing this would be the possibility of some OTA stations sharing the same frequencies as the QAM signals he's trying to receive.

[rockymtnhigh]

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My research has shown that I can't diplex OTA and basic cable; they use the same frequencies.

I can diplex Dish and Basic Cable, BUT there is a chance I will have that overlap problem with the QAM feeds. I haven't taken the time to try it yet; primarily since to do the test I will need to pull the TV off the wall, and feed some coax up the wall; not hard, just haven't had time to try it yet.