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West Union, Illinois | The only reason for two antennas (called co-phased) is to give a directional radiation pattern. Or if you just want the look. One antenna in use and one unused might affect the pattern but it won't be beneficial.
A single antenna will use 50 ohm coax. Co-phased antennas use a harness made of 75 ohm coax. The two legs are exactly the same length and your antennas should be identical. If you adjust for SWR each antenna should be changed identically. To get the best directional pattern they need to be 9 feet apart
What happens when one antenna is longer than the other? Possibly nothing. However my opinion is it will not work as well as it should. And sometimes real world defies theory.
I had a '68 Ford Mustang coupe with 48" Hustler Fiberglas center load antennas co-phased on gutter mounts. It wasn't anywhere near theoretically perfect. They adjusted to a 1:1 SWR I was hoping for a directional pattern for maximum distance. I had excellent range and no discernible pattern effect.
Remember this: If you have two antennas each is half of the system. Each half should be an exact copy of the other half. If the halves don't match they get to arguing over which is better. Instead of working together and doing what you want, one will be stronger than the other. Since it's stronger it talks louder. Instead ear if both antennas working together to put your signal where you want it you'll find it talks better to the right or left
And worse case scenario a mis-match (high SWR) causes more power to be reflected back at the radio and either reduce how far you can talk or damage the radio. | |
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CB Antenna`s
