Diplexer 3way

[keegster17]

Is there something like a diplexer that can combine Ota antenna, satellite, and local cable company? I am trying to reduce cable runs in the house, so much work, where as if I can combine them at the point of entry in the house much easier.

[satchick]

You won't be able to mix all three together. The frequencies used by cable and the antenna are the same, so you will run into two problems: First of all, the cable signal will overpower the signal from the antenna, and you will get all kinds of interference on overlapping channels; and two, your antenna will broadcast the cable company's signal, which is a big problem and could lead to a fine from the FCC.

Also, some digital cable systems are using higher frequencies that extend into the L-band, which is where satellite systems operate. In all likelihood you won't be able to diplex cable and satellite at all. Even if you're not paying for digital cable, in most systems the signal is still present on your line.

So, you can diplex satellite and the antenna all you want, but keep the cable separate.

[keegster17]

I do presently have satellite and cable running out of ecoda diplexers with no issues. So how come this is working?

[satchick]

Whether or not you can diplex cable TV depends entirely on the cable system in your area...It's also possible that those diplexers have a low pass filter in them on the antenna side to block out frequencies above 900mhz. That would also prevent the antenna from rebroadcasting the satellite signal.

Are you using digital cable?

[Terryl]

Satellite and CATV or satellite and OTA but never CATV and OTA.

Cable TV uses a differant band plan then OTA TV, CATV has channels in the normal VHF lo and VHF hi bands but after that it gets differant for the UHF channels.

They have low, sub, mid and ultra bands to get more then the 69 (use to be 83) channels available on OTA.

With digital CATV you can have hundreds of channels, and the entire RF spectrum is used from 5 MHz to 1.5 GHz.

Diplexers have both low pass and high pass filters along with band pass filters to keep down on any inter-mod products that may be created.

To do OTA, CATV and satellite onto one coax you would need a triplexer, this would create one big mess and would not be practical.