CTC-16 Green Picture

[Jon1967us]

Originally Posted by Electronic M

Sometimes the focus rect tube will test good but not work well. I tend to parallel a modern 5KV diode across the focus rect tube as an early troubleshooting check/long term fix.

A few things to watch out for in focus circuits. Corrosion inside the CRT socket and or bad contact between socket and CRT, the 66M resistor, the 6KV ceramic cap on the focus coil can have issues...The collector that reported it had an tuning eye type cap checker and said it didn't fully open the eye on the capacitance test.

When I heard the quick arcing/snapping/zapping sound, when the focus went out a couple days ago, it seemed to be coming from the chassis or HV area, not the CRT socket, but I'm not 100% sure. Still need to check voltage at CRT and definitely that cap and the bleeder.