co-locating CB and scanner on a vehicle

[mike_webb59]

Can a scanner antenna be mounted close(r) to a CB antenna on a car. I would assume that during CB transmit there would be interference but can the two receive.

I have a 3' firestik CB already on my Corvette and I am looking at adding an external scanner antenna. Right now another firestik isn't out of the question.

The only reasonable mounting location is above the rear license plate. I am planning to drop in a BC796D mobile (with remote head) in the rear area of the car, so a FM-adapter won't work.

Also would a common ground plate cause issues.

Any thoughts or technical comments are appreciated.

Mike

 

[N1BHH]

It's preferred that you mount antennas as far away from each other as is possible. Right next to each other is of course, the worst possible situation. Just get them away from each other. If you have one antenna mounted on the left side of the trunk and another on the right side, that's good. One on the roof and one on the trunk deck is good to.

Something that may happen will be your CB getting into the scanner, but that's a trial and error thing. You may have to route your remote head cable away from the CB antenna cable if that occurs. Connecting grounds from the radios to the body is a plus.

 

[mike_webb59]

My second option is something roof-ish. Could go low-profile with something like that. Will investigate. Thanks

 

[key2_altfire]

As a general rule of thumb, you should not have another RF conductor closer than 1/4 wavelength to your transmitting antenna. For CB that's what, like 8 feet? Doesn't sound practical on a vehicle... just get 'em as far apart as you can.

A friend of mine was getting interference on his scanner (the scanner would freeze) when transmitting 100 watts from his 10m radio. He fixed it be re-mounting the scanner antenna below the ground plane of his 10m antenna. This worked fine, and it was free. So if you can get your scanner antenna below your CB ant's ground plane you should consider this. (Of course it requires a low-profile scanner antenna.)