My original VHF radio on my 1988 hunter 23 will turn on but not lock on any channels. It will scan the weather channels but not lock on to any of them. I checked all the connections in the cabin and on deck but can't locate any problem. It was working great, but the next time I turned it on I had the problem. When I adjust the squelch, I get static. I'm not sure how to test the antenna with the mast up. I would appreciate any help you can give me.