RCA 21-D-7177 Horz Drive Issues

[Penthode]

Originally Posted by Kevin Kuehn

But, if the right side "were" compressed, would that also be causing the left side picture to be cut off (no horizontal space bar?) I didn't think it would do that.

Remember that the horizontal output tube only begins to conduct from the middle of the scan to the right of the screen. If the tube is weak then the right of the screen would be compressed. The fact that the voltages are normal and you have a healthy scan otherwise points to the output tube.

Is the 6DQ6 screen voltage correct? Perhaps the screen resistor has drifted upward or the screen decoupling capacitor is faulty?

Originally Posted by Kevin Kuehn

It sure would be interesting to have the actual RCA service literature for this chassis. Possibly there are notes about scan issues.

I do not think the RCA Notes will share this information. However I do recall some good articles surfing the web. I just can't seem to find them at the moment...

Originally Posted by Kevin Kuehn

Does anyone know what was used for pincushion correction (if any) on this TV? Watching this 8" test CRT, the pincusion effect is really bad.

Small permanent magnets can be used on black and white set to correct pincushioning. They will be placed either side of the yoke near the CRT.