You really need to get some way to check your swr, or at least match the
antenna. The auto tuner in the 480 will take care of things nicely,
but I would only connect it to a "real" antenna. From day one, that
snake thing sounded like a disaster waiting to happen. With no idea
what the swr is, I'm surprised it didn't smoke sooner.
As has been said, Kenwood service won't touch this one. Even when you
find someone to work on it, some parts can be hard to find.
73, Steve KW3A