Quote:
Originally Posted by Aaron62
I have a dumb question here so please forgive my ignorance in advance. Is there a difference in mounting heights for combining UHF and VHF antennas? Or can you mount a VHF in one location like the roof, combine it with a VHF in the attic?  |
1inxs has it right. Maybe another way to understand this is if you combine antennas with a diplexers, you don't need to have the same coax length to each antenna. A UVSJ is a diplexer not a simple combiner.
http://www.dtvusaforum.com/dtv-recep...html#post19228
A UVSJ blocks reception from the other antenna on the other band by about 20db. So even if a UHF signal coming from the VHF antenna reaches the UVSJ out of phase, it's so far down in level it doesn't matter too much. A real purist would probably make them the same length, but in reality it makes little difference.
Now if you decided to combine them with a simple combiner, you need to have the coax the same length to each antenna. This is because each antenna UHF vs VHF will pick up some of the other bands signal. If the coax is different lengths, then the signal will reach the combiner a different times causing mulitpath.
Do you mind if I move the posts related to this in the thread to a new thread? It's an excellent question and would be good to find linked in it's own thread.
