Darryn replied:

David you could try a Uniden dealer as I think your radio is a Uniden radio with Pearce Simpson branded on it. Also what is the problem with the squelch as most Uhf/Fm radios the squelch is either on or off despite many Uhf CBs having rotary controls? This means that once you remove the hissing/rushing noise you are not doing much more. Also if your set has inbuilt selcall facilities you may have enabled the Quiet mode which means you wont hear anything until someone sends your selcall code from another radio.
Hope this might help,
regards
Darryn