It depends on where the radio is. I had a squad car that had the same problem, there was a Motorola mobile mounted either on top or bottom (can't remember which) of the siren controller. The radio had a mini-UHF connector and the shell and worked it's way loose so only the center pin was making cont...

If you do tune up a VHF phantom you HAVE to set the power output to 5 watts maximum. Infact I would tune any of those with minimum power levels. These suckers get hot when transmitting, I tried tuning one up using a Motorola "diddle stick" and the unit got so hot it melted the plastic. :o ...