For what its worth, It may not be either the radio or the antenna.
While in the Broughtons last year we experienced intermittent problems with our VHF. Sometimes it was great, sometimes we came across very faintly....
Afeter we got home, I took both the radio and antenna into a local marine electronics shop here in Portland, only to be told there was nothing wrong with the radio, and that my solder job on the antenna connector was fine, and the antenna was functioning as advertised. The technician then asked me to show him how I was holding the mike...... When I wrapped my ham hand around the mike, he said that he saw the problem... When you have your hand over the little tiny hole that is the orifice for the microphone, it tends to damp the voice a bit (or a lot, as I discovered). You have plenty of carrier, but no voice. As Homer Simpson so eloquently said, "doh"!
So the cat's out of the bag. I failed VHF 101. On the good side, it's nice to know I still know how to solder coax, and that the radio's OK.
Steve