[glyphmon]

Okay, another mystery has opened up, and I'm sure this one has to be my fault.

A fresh set of voltage readings:
6F6G
Plate: 240V (240V)
Screen Grid: 259V (250V)

RF 6K7G
Plate: 254V (245V)
Screen Grid: 76V (70V)
Suppressor Grid: -3.16V (?)

6A8G
Plate: 261V (245V)
Pin 4 (grids 3 and 5): 75V (70V)
Osc Control Grid: 192V (?) ***
Osc Plate: 262V (150V) ***

6Q7G
Plate: 182V (150V)

IF 6K7G
Plate: 250V (250V)
Screen Grid: 75V (70V)
Suppressor Grid: 0V (?)

So by comparison, most of these are spot on, but now, for some reason, the oscillator section of the 6A8 is completely out of whack.

Now, the socket voltage diagram doesn't say what value the Oscillator Control Grid (pin 5) should have, but it previously was a negative, approximately -10V.  Tracing the path through the schematic, it looks like it comes up ultimately out of the tuning subchassis and connects at the junctions of Resistors 17, 29, and 64, where I usually have around 200V.  So maybe this is correct and I should have worried about the -10V previously?  The 6A8 data sheet says pin 5 is grid 1, which doesn't get spoken to by number in the sheet that I've been using, so I can't even really tell which voltage they prescribe.  Maybe they don't, and maybe I'm worried over nothing.

In any case, the Oscillator Plate (pin 6) voltage being 262V where 150V is expected (at least according to the socket voltage diagram), seems extreme, but that comes through the 1st IF transformer primary, and from there, Resistor 33, where I'm having about 262V, down from 264V before the resistor, so I don't know how to take that value either.  Bad diagram?  The data sheet says this is grid 2 - the anode grid, which is supposed to have a max of 200V, so that worries me.

Aside from that, the plate on the 6Q7 is still high, but that hasn't changed.

Thoughts?  Am I worrying too much?  The voltages are now at least pretty steady though there may be a +/- 1V here and there.

I'm not sure how the voltages on the 6A8 could have changed so much from just what I did with the 2nd IF transformer (removing, fixing, reinstalling). I think the only thing that was adjacent was the connection to R33 but there's no short there, they are still separated. I would think if I had something installed wrong, the radio would perform much worse and I'd see weird voltages in more than just one place.

No alignment tonight - figure I'd pick your brain on these readings before I commit.  I also don't want to fry the 6A8 by running it with too-high voltage, certainly my a margin of greater than 20% over its advertised maximum.

Best wishes,
Roy