Paul,
I had some wierd static from the alternator
brushes when they wore down short. This doesn't seem to fit your cause and
effect pattern but it's easy to check for in flight by shutting down the
alt. I expect you've probably already tried to trace this by alternately
killing systems.
When I got the plane, about 9 years ago, the
radio shop I went to couldn't get satisfactory performance on the internally
mounted antenna. Their solution was to mount an external belly whip with a
ground plane of about 12" square under the passenger seat. In the interest
of trying to beat Larry Henney in the Airventure Cup Race, I've since mounted
the whole assembly inside the tail cone.
Mark Ravinski
N360 KB
After about one
half hour of flight, I frequently get static on VHF comm channels. It
usually grows with time until radio reception is marginal. Strangely, the
static isn't a problem in the terminal area at the end of a flight. My
antenna is a dipole, mounted inside the vertical fin. I suspect that a
static charge on the skin may be responsible. The skin surfaces are not
grounded. Has anyone else had this problem? If so, how have you
solved it?
Thanks,
Naf
Paul Nafziger
LNC2
N7PN