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Old 24-Jun-2015, 6:02 PM   #15
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,747
Quote:
I know there's VHF/UHF diplexers out there (my antenna's pre-amp has one), but is there anything that I can use to combine two UHF channels? Or would I be stuck with having to rotate the antenna?
How would I combine the 2 antennas? I hunted around for diplexers a little bit, and most of them seem to be UHF/VHF. In this case I'd be trying to get UHF stations with both antennas.
As you are aware, a VHF antenna and a UHF antenna are easily combined with a UVSJ, which is a UHF/VHF diplexer. Combining two UHF antennas is not easily done in all cases.

If you have two identical antennas that are aimed in the same direction, you can combine them with a splitter in reverse, if the coax lines are the same length. The signals arrive at the combiner in phase, so they add together for more gain.

If the two antennas are not aimed in the same direction, the same signals from each antenna might not arrive in phase at the combining point, causing the two signals to interfere with each other. This is why the DB8E doesn't do what you expect it to do when the two panels are aimed in different directions. Sometimes it works, sometimes not; trial and error.
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