can a cb radio antenna be used for fm broadcasting thanks
Actually yes but you have to modify it by removing the loading coil and any other oddball parts like a capacitor inside the base which some CB antennas have. You will want the length of the whip to be 234/mhz. So if you broadcast on 96.9mhz for example you would want the whip to be 2.4 to 2.5 feet long which luckly some CB antennas happen to be this exact length I have found.
This will only work well if you are using the whip antenna above something metal that is grounded like a car or a metal shed, and obviously helix antennas like those used on trucks as twin antennas won't work.
Best way to make an antenna out of old CB whips is to unscrew the whip from the bases, find a bolt that fits the whip part so you can attach it to something, then take two whips both at 2.5 feet length and attach them in a dipole configuration. You can use PVC or other common things to isolate the two halfs. Here is some info on the dipole antenna design, aka your best bet for simple antenna... en.wikipedia.org/wiki/Dipole_antenna
Like said though you can use one half of a dipole (simple single whip antenna, also called a quarter-wave antenna) but that usually only works well high above ground or on metal surfaces.
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