> On Jan 24, 2022, at 17:35, Douglas L via Amps <amps at contesting.com> wrote: > > I had lot of trouble with the Eimac 3-500 in the mid 1980’s. My feeble brain seems to remember issues with 8877’s, in the 80’s. Serial numbers or date codes. Might be worth a search, if cleaning out a basement.