Today's Mystery Guest (RCA CTC-4)

[Phil Nelson]

Well, I'm making slow progress. The B/W picture is very watchable -- good contrast, brightness, focus, geometry. I worked through the purity drill and all seemed well. Got nice clean red, blue, and green rasters. Those big magnets in the field neutralizing ring are pretty fun to use and they work well. I made the convergence decent in the central zone. It's not so hot around the edges, but there will be more time to play with all those dynamic convergence controls later.

When I display color bars or play a DVD, there is basically no color, even with the killer threshold turned all the way down and the color control turned all the way up. The AGC control seems to operate as it should. I tried tweaking the oscillator on one channel and convinced myself that fine tuning is not the issue.

Tomorrow is another day. I guess I will start at the color takeoff (chroma bandpass amp) and start working downstream, looking for problems in the color path.

As for using a 21AXP22, you bet I'd use one if I found one. I'd drive a 1955 Corvette if I found one of those, too, but meanwhile, we make do with what's on hand

Regards,

Phil Nelson