Hello. I've the above radio. I've been doing OK with it so far until the other day. I mistakenly reversed polarity on the DC cord, popped the fuse, replace fuse, and it powers up, receives OK, and over all is fine with one exception. After this event, I go to transmit. The rig will transmit for a half a second, emit a dual warble tone,but doesn't transmit any further. Power is still on, all other functions are normal. What's this mean? Did I trash the radio permanently? Any resolution? Thanks for your response.