ok, adding the .01uf cap as shockwave suggested did change the vac reading, and although it still changed, the fact that it raised to a bit of a lesser value says to me that i am indeed dealing with RF getting into the meter so we'll let that go for now.
I just put in a set (not matched) of 6LB6 tubes i have lying around for my own amp project and the amp does seem to act more like i was used to seeing last time it was here.
both TUNE and LOAD controls peak very near the fully MESHED positions, and this is with no turns on either coil shorted. once it cools down im going to try spreading both coils a bit to see what changes.
then another test with my personal 6LB6 tubes.
then fully cooled down again, and a test with the owner's 6LF6 tubes and no other changes, in hopes to see what changes.
I wish i had a tube tester here so i could give some more info but alas i don't.
i am now under the strong suspicion that the owner had the amp tuned wrong, talked on it pretty heavily, and may have damaged one of the tubes.
honestly that sucks to have to tell someone they don't know how to operate their own amp, but luckily BBI has a video on tuning old sweep tube amps that seems to be pretty accurate.
maybe he'll believe BBI if he doesn't believe me.
LC
