If you're an amateur radio enthusiast and recently purchased a 2-meter VHF-band ham radio, you can convert your old CB antenna for use on this radio frequency. A CB antenna, built for the 11-meter band is typically over 100 inches long. A VHF ham radio antenna, in contrast, is about 20 inches long. Once you cut your CB antenna to a VHF length, it will no longer be effective for CB use. You will, however, have an inexpensive and high-efficiency VHF antenna, rugged enough to be mounted outdoors.
Measure and mark a point 19-1/2 inches from the base of the CB antenna.
Cut through the CB antenna at this mark, using a hacksaw.
File the sharp edges from the new tip of the antenna. Wrap the tip of the antenna with electrical tape to seal out moisture.
Connect the antenna's coaxial cable to the external antenna jack on your 2 meter radio receiver.