poor signal using diplexers

[ohmster]

I have a H21-200 box with the 3 LNB dish. I am using diplexers in the system.
I diplex the ant and LNB signal send it to a remote location, pull off the LNB signal to the box where the output is modulated to ch 14 UHF. This ch 14 is then combined with ANT signal and distributed to rest of house.
Prior to having HD sat this system worked good. Now with HD the signal is very poor. If I remove the LNB to the diplexer the signal clears up.
I have heard that I can't use diplexers with the HD sat. If thsi is true are there any filters.....that I can use? Thanks in advance for any help.

 

[boba]

The correct method is to use a separate cable instead of diplexers. The 99 satellite uses the same frequencies as OTA channels so you are trying to put 2 signals onto the cable and they interfere with each other as you have found out.

 

[twizt3dsist3r]

what you could do is move the bbc off of the receiver and install it at the begining of the run from the dish before the diplexer.

 

[ohmster]

thanks

thanks for the help, I will try the BBC.