commercial uhf antenna

Hello everybody, I have a DB201 UHF and I would like to convert it to VHF. Does any of you have try that? If yes, - How you did you extended the radiation element? - How did you seal again the epoxy in the middle of the antenna? - Did you use the same impedance adapter? or it has to be...

Hi Folks, I'm in need of a UHF base vertical antenna that covers around 415 MHz or 455 MHz. Gain should be 5+ dB. I was wondering what antennas do public safety agencies use. Any idea would be appreciated. I came across Antenex @ FG4505 Antenex Laird UHF Fiberglass Omnidirectional Antenna but...