1971 Curtis Mathes tube type color set

[Chad Hauris]

This set is a clone of an RCA CTC-25 with some engineering improvements. It has an epoxy-encapsulated flyback, a 6BQ5 audio output tube, IC audio demod (like the CTC-25 but a DIP IC) and cooling fins on the power transformer.

It had no power when I got it and I found there was a splice joint where a power resistor was replaced that had no solder and there was a bad soldering job on the rectifier diodes. Fixing this got the power supply working (I think I will replace the electrolytics just to be safe although the original ones don't seem too bad).

The CRT socket was bad, no filament voltage to the CRT so I substituted one in from an XL-100 (will solder the joints later.) I used the CRT tester to do a clean and balance and gave it 7.5 volts on the filaments for a little while and the CRT tested pretty good then. It is made by GE (EIA code 188).

Also the focus rectifier tube was bad and the pins were oxidised resulting in low focus voltage even with a new tube. Some deoxit on the pins fixed that.

I still need to clear up a video peaking problem with intermittent changes in sharpness of text and the sound is not working at all yet.

The cabinet of this set is very cheap. Particle board, masonite, and plastic.