"Jim - NN7K" wrote in message
. ..
Try search under ANDREW, or Decibel Products. It sounds like you have the
222 series (4 folded dipoles stacked either in the same plane, or in
4 different directions. Though doubtful that you can change resonant
freq, most likely with what you have will be entirely adequate for a band,
even 10-20 MHz from its design frequency
these models are fairly broadband antennas. As info, Jim NN7K

Modify a 150-160 MHz DB-222 or DB-224 for the 2-meter ham band usage
(w/photos) --
http://www.w4dex.com/kc4fwc/modify.htm