Don't worry about the ringing. It could be normal, or it could be caused by the main problem.
From before: "Test point 1, is close at 8Vpp 2.4vpp hotter than spec at 5.6Vpp." Maybe it's worth while to track down why this voltage is high. It could be due to high feedback drive to V7 for the oscillator to run, or it could be due to reduced loading at Test Point 1 to the other circuits.
Good points Tomorokoshi. I assumed high from going 115 to 120V. But then the unit passed the
103V to 127V test for regulation. It didn't deviate at all. Also figured that might be a good
sign to not mess with changing the capacitors for a while.
Looking at Test Point 1 from the 20 KC Oscillator, follow note "40 KC Output To C28 & T4".
T4 is in the 40 KC Phase Shifter circuit, and C28 is in V5 Detector Gate Amplifier circuit. Are the components in this path okay? How do the signals look? What about Test Point 6?
See "4-45. 40 KC Phase Shifter" on page 4-5.
I Checked the components in the path. The only hard part
is trying to read c28 as it's in series with the transformer.
was reading something on the order of 587uF...which made
no sense. I think one other of these ceramic caps tested that
high, the rest were close around the .01uF value they were supposed
to be.
Haven't powered up and looked yet.
Also, are the contacts on the two selector switches tarnished? Test with the unit unplugged and see what the resistance is between the wiper and the selected switches at the soldered wire terminals. If possible check all settings on both wafers.
This took a while as it's a PITA to get to all the switch positions,
however, I checked them all and were generally fine. It took
a bit of finagling to reach all and proper measuring.
I'll either continue tomorrow evening and post pics then.
My LCR meter is out of commission until new probes come
in and I can solder them into the fixture.
It's a DER EE LCR DE 5000 and the short alligator clips came off trying
to get them around something a bit too large.
Also looking around for some of the tubes and I'll replace some of the
marginal tubes:
All 3 6ah6 tubes are marginal.
I found some 6AU6s that are better then what was in there,
they are right on boarder of usable for Tektronix screened tubes.
I wish I had a source for the HP 6DJ8s, could use some of these.
The only one I couldn't test was the 5651 92V zener tube.