Thread: 91XG or DB8e
View Single Post
Old 9-Aug-2017, 10:57 PM   #8
Retired A/V Tech
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,483
is there a method of combining the 4 antennas that doesn't introduce the loss of a splitter/combiner?
The method that ADTech suggested, combining after amplification, doesn't eliminate the combiner loss, but it does make it irrelevant because the signals are stronger before that attenuation.

So, having two preamps and having two coax lines would allow you to combine after the two power inserters and avoid a custom power supply needed to power two preamps through one coax.

No matter where the combiner is located, after the UVSJs or after the power inserters, you are still combining two UHF antennas aimed in different directions and two VHF antennas aimed in two different directions. This means that if two antennas pick up the same signals, when they arrive at the combining point they will interfere with each other if they are not in phase.

The only way to avoid that is with single channel amplifiers, single channel antennas if necessary, and combine into one coax like a CATV headend.

If you can not measure it, you can not improve it.
Lord Kelvin, 1883

Last edited by rabbit73; 9-Aug-2017 at 11:01 PM.
rabbit73 is offline   Reply With Quote