mobile fm broadcast antenna

[tpbaker]

someone posted this:For best performance, the antenna should be on the outside of the car, a good place would be the roof. You might be able to use a CB magmount antenna. Just remove any base loading coils and trim the element for the middle of the FM band.

could someone please give more detail about doing this?

[Disasterguru]

A mobile antenna would be quite feasible for operation in the FM broadcast band.

Probably the best antenna for starters would be a 1/4 wave design, using the roof of the vehicle for a ground plane. Yes, if you use a CB antenna, you would have to eliminate the loading coil.

To calculate the length for the whip, simply use the following formula:

234/freq.in MHz X 12=length of mast(in inches) The length for mid-band would be approximately 28.6". If you can find a ham operator with an MFJ antenna/swr analyzer, it can make the job much easier

At resonance, this antenna should present close to a 50 ohm match.

Good luck and let us know how your mobile operation turns out!

RadioRod