Pincushion adjustment - admiral tv

[maxhifi]

Thank you for all of the advice! Since the picture tube is what it is, I decided I may as well just make this TV as good as it can be. The picture is not ideal but it's more than acceptable for my needs, and as you say, learning is good. I just put in an order for a full complement of Panasonic film capacitors, at digi-key, to replace all the white ones (if I am going to replace three of them, it's not a lot more effort to change them all), and some new electrolytic capacitors to replace the can. In the mean while I will test all the tubes, and see what I can do about replacing the weak ones.

I don't really expect new capacitors to make the TV perfect, but they sure won't make it worse and then I can begin troubleshooting without knowing there's probably a bunch of bad parts in there. I don't own a capacitor tester so that's not really an option.

Tom: I already cleaned all the controls and the tuner, that's more or less the first thing I do with old electronics.

[DaveWM]

sounds good. if you have a scope, a tv is a wealth of signal sources to look at, just beware of hot chassis sets anytime you start connecting AC powered equipment to them. I always run hot chassis thru isolation transformer anytime I have the interlock defeated.

[maxhifi]

When I revived an RCA 8 inch portable a couple years ago I had a lot
Of fun viewing all the waveforms with my oscilloscope. It ended up nearly working like new aside from some "jail bars" I could never track down the cause of. I have also used the oscilloscope to align FM radios with a sweep frequency generator, and countless amounts of audio equipment repairs. TV sets are complex enough that every time I work on one it seems the problems aren't the same, however I do have some background in electronics.

[DaveWM]

thing about TV's is you "see" the problem, which on a large CRT can make minor defects very noticeable. Good luck with it

[maxhifi]

I will update this thread once the stuff from mouser shows up and I get the capacitors from mouser installed. Thanks for the advice, I am curious myself to see how this works out.

[maxhifi]

All new capacitors installed tonight - pic looks way better in terms of contrast,
But "pincushion" problem still there. I was watching it a good while last night - man is David Letterman looking old!

Still haven't tested all the tubes, "recapping" only took about two hours but took up all my "tv" time last night.

Where are the PC correction magnets located in the yoke? I pushed the yoke tighter up to the jug than it was before, and I think the distortion became worse... I am going to take the back off the TV again tonight and try backing the yoke away from the jug and see what happens. There may be some deteriorated spacers in there allowing me to push it too far forward.