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Congratulations! I'm glad somebody suitable actually took the set. I too got
a CT-100 from the ETF.
I decided not to do a cosmetically correct restoration, mainly because
I decided that restuffing all the "can" electrolytic caps would be too dangerous to
nearby parts.
I removed the orange selenium rectifiers and mounted the filter caps and dropper
resistors on epoxy tag boards in the cage. I also added several additional fuses.
I had trouble with focus voltage stability and finally used a long chain of 150 volt
Zeners to regulate it.
This set has 82 total adjustments (counting only one channel in the tuner). That includes all the yoke and purity coil physical motions. And every one has to be right!
I found that replacing the myriad bad "white" peaking coils with even the RCA specified
alternates may not be optimal (due to differences in intrinsic parallel resonance frequencies). I bought several different coils of the specified inductance and used the ones that gave the best frequency response. The 6.8 mH one in the Q channel is clearly the wrong value; 3.3 mH is more like it. It turns out that 82 adjustments is one too few: you need one more adjustment in the color matrix to get it exactly right.
The specified values are the nominally correct nearest standard values, IF the feedback resistors in the adders are all exactly the same. I found that getting the correct color gradation in the violet through magenta range while all the rest was OK took a bit of tweeking the matrix. This can be done by looking at color bars on a scope
to match the pattern in the manuals.
Getting all the RF-IF-color amp alignments exactly right is critical for the
best picture. Its possible to get all the colors exactly right and no ringing in the
picture at all if all those adjustments are correct. See the pictures I posted in my restoration thread.
Finally, and most inauthentic of all, and entirely optional, I added a parallel combo of
a 100K resistor and .001 uF 6 kV ceramic cap in the leads to all three CRT screen grids. The 21CT55 has the resistor to protect the CRT cathodes in case of an arc. I added the small caps as just the resistors caused some minor color shading problems. I did this after original my CRT got slightly gassy and arced, destroying the red gun. It took two years to find a good replacement CRT.
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