View Full Version : using diplexors
Kpatel516
11-07-2003, 10:35 PM
Im planing on installing an OTA antenna on my roof..i also have a dish system installed in my house running to my HDTV. can i put a diplexor on the roof to connect the dish signal and antenna signal so that i dont ahve to run wire again or will that degrade the signal for the DTV broadcasts. and would i need two diplexor (one on the roof and one next to tv)???????
thx alot for ur input guys
much appreciated
FullBandwidth
11-14-2003, 09:58 PM
Your assumption is correct - diplex the antenna and dish signals together outside, bring the one coax line into the house, then another diplexer splits it back into the two separate signals.
Some STBs (I know for sure the Hughes E86 for DirecTV) have a diplexer built in the SAT IN signal, so the "inside" one isn't necessary with that setup.
Wooger
11-16-2003, 06:51 PM
Be VERY careful... a couple of things to remember:
1) The DTV receiver pumps voltage down the coax to power the LNBs at the dish.
2) Some Omnidirectional antennae also pump voltage up the coax to the disc to power an internal amplifier. Radio Shack and Weingard both do.
Putting a splitter or combiner onto either or both of these can possibly block or WORSE send the wrong voltage to the wrong items, etc. If you must combine, do it AFTER the voltage pumps... the little power box for the amplified omnis or after the DSS receiver.
Hope this helps.
FullBandwidth
11-17-2003, 09:53 PM
Good points, Wooger. Also, make sure you're using diplexers specifically designed for sat/terrestrial use, not something else like uhf/vhf - the latter are definitely not designed to handle the DC voltage for the LNBs.
