TV repair books

[marty59]

I have a Howard Sams publication #20361 "TV Servicing Guide".."Arranged by Trouble Symptoms" by Leslie D. Deane and Calvin C. Young, Jr.
It's nineteenth printing was in 1973 that appears to have been around since 1956. Does not cover anything with color but goes over a lot of the older designed B&W circuitry in a straighforward manner, with lots of pictures and covering all the stages.

[DaveWM]

Originally Posted by cbenham

I have a set that 'breathes'--an RCA 9T-256. I also have a 9T-246 that DOES NOT breathe. ??? I can't see any ripple on the B+ lines anywhere in the sweeps or the power supply. The only difference between these two sets is that the 256 has a relay with a wired remote switch to 'expand' the size of the image.
It works fine but the picture breathes in both modes. Could this be caused by the power transformer radiating magnetically into the yoke? I tried placing a steel panel between the yoke and the xfmr but this didn't do anything to reduce the breathing. Any help is greatly appriciated. Thanks, Cliff

if the freq is slow, then like mine it may be a beat freq of the AC line and the vert sweep. If that is the case you could do like I did and see if running the vert tubes on DC filaments makes it go away, or better yet, just make sure you have a good ground return on the filaments (which was the cause for my breathing issues).

[cbenham]

Originally Posted by DaveWM

...just make sure you have a good ground return on the filaments (which was the cause for my breathing issues).

Yep it's the vertical beating against the 60 cycle line. Thanks very much. I had not thought of it being a heater circuit problem, but I'll sure take a close look at that wiring.

Cliff