TV repair books

[kx250rider]

I just had a thought on the Magnavox... Have you thought of the degaussing coil thermistor being bad? Try unplugging the degaussing coil. I've seen those change value, so that they keep recycling. Usually it will burn out the coil, but I suppose not always. That will definitely cause a snaking or breathing of the picture, and load down the B+

Charles

[DaveWM]

not color, I did not think B&W had them?

there is a thermistor in the yoke, now sure why its there.

Its a very regular pattern, I can see it in the B+ and it matches the screen wave in frequency.

if you look at the ripple of the B+ you can see a rolling wave that is on top of the regular ripple, it takes about 15's to go one full cycle.

You can really see it when the horz id adj so you can see the black of the picture just beyond the scanning on side. Its a low amplitude low freq wave that works thru the whole picture. At 1st I was willing to just say it is a weakness in the circuit design but the other chassis with the same design does not do it.

The only other thing is the fly back is really really bad looking on the set that works. I figured it is making HV so I assume it is ok. I have a spare yoke that I may try just as a process of elimination

I need to get the sets side by side and scope them with a dual trace scope and see if anything shows up.