I had a problem last year with my AL-811. I purchased
it brand new form R&L Electronics in Hamilton Ohio
and after 4 months, 2 of the 811's developed vacuum
leaks causing them to fail. Ameritron's customer
service wanted me to ship the tubes back them so
"they" could determine if the tubes had failed. The
guy at customer service was an idiot so I went up
the food chain and spoke with Mike Enis, a supervisor
at Ameritron. After I explained everything to him, he
said, "we'll pay to ship your amplifier back to us.
Package it up in the original box and I'll send you
the UPS shipping account number." They did just that
and within a week I had a brand new amplifier.
Here's Mike's e-mail address or you can call
Ameritron and ask for him.
"Mike Enis" <email@example.com
Hopefully he still works for Ameritron. I can't say
for sure you'll get the same result but it's worth a
try. Make sure you have all the documentation
including the repair docs. Without them, they may
not be able to do anything.