[Amps] AL-1200 Ameritron help request...

[Dave Weiss]

Hello:

I have a new AL-1200 and it performs just fine on all bands.  It has an
issue that I did not expect:

When I first turn it on, it is normally quiet, the blower on factory setting
(medium) is NOT noisy.  The plate voltage is 3500-3600 depending on house AC
usage.  After a minute or so, a loud buzzing sound is heard.  Ameritron
guided me to a relay mounted by a 1/4 inch stud and nut on the rear of the
unit.  The nut was loose and tightening it seemed to correct the issue for a
few minutes.  Pressure applied to the rear of the unit changes the pitch of
the buzz.  Everything else on the rear panel is secured properly.

Has anyone experienced this problem?  Need some good help.

Best 73

Dave K3FT