I made some fairly decent progress today! I focused most of my time on cleaning up and rebuilding the vertical and horizontal sync/deflection circuits. First item on the list was cleaning the high voltage cage, especially around the rectifier tube. I was a little irritated by the design of the removable portions of the shielding; the top section, where the flyback mounts, can only be removed if you unmount the yoke socket and undo some of the harness looming. I ended up leaving it in place and using Q-tips to get the worst of the grime out. The 1X2 HV rectifier appears to be original. I noticed the vertical output tube and one or two of the IF tubes have been changed, so I have to say I'm impressed it's still on its original set of horizontal sweep tubes
Most of the deflection circuitry is on the PCBs, but a non-insignificant portion of the horizontal section is hand-wired underneath. It looked deceivingly simple at first....
....but there are actually
SEVEN capacitors down here that need to be changed! Technically eight to start with, but two of the paper capacitors near the horizontal width coil are in parallel (a .02 and .05uF) - easily replaced with a modern .068. I was initially expecting to have this portion of the chassis done in an hour, but kept finding more paper caps the more I dug
Mercifully, the resistors test great so far. They're all within 20%, but many even measure 10% or better. Perfectly acceptable for a tube set, and I would rather keep as much of this onion un-peeled as possible!
I managed to get most of the deflection PCB recapped as well. With one exception - there's a 0.025uF 1.5kV paper cap on the vertical output tube plate, I don't have any of those. I experimented with using a few 0.01/0.015uF caps in parallel, mounting one on the underside of the PCB, but nothing came out to my satisfaction. Mostly, the top-side capacitor rested too close to the tube for comfort. I don't want them to get baked and potentially damaged over time. I've got some 2kV axial films on order and hope they arrive later this week so I can wrap this part of the set up for good. In the meantime I'll try to get a little more of the grime out...this thing is FILTHY!
The 9-5 coal mine beckons me to return, so things will slow down over the week, but I hope to have the rest of the paper capacitors replaced by next weekend so I can begin testing and potentially diagnose more problems.
On an unrelated, brief note, I found the first actual difference between the schematic for the 10PG and my 10PK. The 10PG uses a 4R-HH2 for the tuner RF amp; my 10PK uses a 3D-HH13 subminiature there. I have to admit I've never seen a subminiature of this type before, it's kinda cool! I just hope it's good as I have no way to test it...
