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Okay so an update on the Bench Queen; it's running. I still have to iron out a few ripples in the IF section but it's a happy set after 20 years of idle time. Going to run thru the Heathkit manual for the IG-57A sweep/marker generator again and see if I can't find why the markers themselves are dead.
The big issue came down to a bum resistor on the horiz keying pulse, schematic called for a 270K and by color codes that's what I replaced the original with, turned out to be 27K on the meter. Red-Violet-Orange and 5% gold stripe so I went thru and verified ALL the replacements. Guess that's why Ohmite calls them "Little Devils". So once the correct value was in place everything started to act normally, AGC is good but still getting the horizontal bends and trails on high contrast scene details, vertical size is a little challenged despite a new tube and known correct resistor values. I suspect the Boost B+ is low.
Convergence was a challenge that had me stumped for several hours, replaced all the selenium diodes on the board but wasn't getting the correct horizontal actions until I bumped the input connector and discovered a number of traces had broken right where the Molex pins were soldered to the board and lifted the pads. Servicing the set I'd run it with the chassis out of the cabinet sitting on some tape cases then when it was time for the bench would just disconnect everything at the Molex connectors, the sheer number of cycles broke the traces. Once that was rectified the convergence fell into place for the most part, still doesn't respond to the R/G diff tilt so that's on the to-do list.
So overall it's getting there, not quite up to where it was back in the day but now an incentive to keep moving forward. One thing it still has is RF sensitivity. Growing up I remember the DX football games with this massive antenna and Alliance U-100 rotator, there were tape markings for the station positions all around the face and every fall we'd have to check all the flat cables. In the house I can run the modulator on a 1/4 wave antenna with good results.
Got loads of detail pictures of the chassis and operation, give me some time to smash them down to fit the server limitations and I will post them
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