RCA 21" triage CTC20 CTC16x CTC12

[DavGoodlin]

213G216MU-CTC12B.jpg
As you can see some rust where mice peed on the CTC12B chassis but only destroyed the damper tube socket, the filament keeps going out. All 4 PC boards were spared the . This set was full of nesting material when I got it.

This looks very promising as long as there are no gremlins like the other two chassis. The 12's HV is robust at 25 kV (dark screen) and adjusts easily and so is audio. I can’t get a picture unless I reduce then advance the contrast control and see a momentary flash of a raster. The service switch gave me a fuzzy but solid line that I could verify R-G-B screen controls operated. I pull out my handy “Pomona” CRT adaptor so I could easily measure crt gun voltages, and they looked within 10% of schematic K=335v, G1=190v, G2=615v

It was then, right at bedtime that I noticed a little black wire was missing from the 4.7meg 2w resistor in the HV cage to the CRT socket for the focus anode. It must have been pulled out of the CRT socket, leaving the pin when I initially got the set and immediately cleaned it out 5 years ago.

The CRT socket has two rivets so I can access to solder on some Belden wire rated for 20 kV that of similar size and black insulation like original. I can replace the wire to 6DQ5 cap as well. If this works out, I will do all the electrolytics, they being even older than me