admiral 24c15 with 20b1 chassis attempt at restore

[fumplet]

gassy 1b3??? I had a philco 80 tube do that untill it failed. I guess I will go back to figuring out what makes focus work. cant get horizontal to lock yet.

[bandersen]

Check the power resistor in series with the focus rheostat.

[fumplet]

r332 I think your reffering to and that says 3000 ohms on schematic. Checking now. The 25 watt power resistor 8500 ohms in the hv cage is open.
trying to come up with an 8500 ohm substitute in the mean time. 25 watts is definetly a huge one

[bandersen]

Yep, they're always open.
You can use a 10K - 20W (or better) in parallel with a 56K - 5W resistor.

[fumplet]

the sand resistor measures 1.867k ohms.

[fumplet]

I found two 12k ohm 20 watt resistors which would make 6k or just use the one 12 k ohm itself.

[bandersen]

The 8.5K resistor in the cage has a big impact on the horizontal linearity. Try both and use the one that looks better, but I suspect you'll need to get closer to 8.5K to get good results.

[Yamamaya42]

Originally Posted by bandersen

Yep, they're always open.
You can use a 10K - 20W (or better) in parallel with a 56K - 5W resistor.

Was I lucky then that mine was OK?

[fumplet]

I guess I will just put the 12000 in for now as I dont have anything smaller or a 56k that will work. Going to order a 10k adjustable 50 watt one.

[fumplet]

Im wondering since focus is just voltage supplied from the power supply to the focus coil that a connection issue is up because focus rheostat is good as well as the sand resistor as well as the focus coil itself. I had the tv on its side and ok yeah I got some focus adjustment back, put the tv right side up no focus. Gotta be a connection issue and I suspect that power socket plug rear of tv for starters.
Messed with the horizontal linearity adjustment because it was screwed most of the way out like an inch and almost a half of threads sticking out. I can get picture to stop rolling and almost sync up but not sure what to adjust next unless controls on the back are still way out of adjustment. I tried flipping around the ionmagnet and that made centering a nice bright picture much worse only half the image showed up so I put it back the way it was.
I figured well maybe they messed with the magnet and screwed that up too.
Not sure how the 12k ohm resistor is affecting me getting an actual picture. but focus is still no go.
https://youtu.be/4_xPEqhBqdU

[bandersen]

Have you adjusted the horizontal freq coil?

[fumplet]

if the horizontal freq coil is on the back of the set then yes. Have seen horiz lin and horiz lock. I can get horizontal lock to sorta untear the picture midway adjustment but I would think it would keep untearing and show a picture but picture just gets worse outside either way of halfway point.

[Chris K]

Originally Posted by Yamamaya42

Was I lucky then that mine was OK?

The dreaded RCA with the horizontal devil still lurking in it has the big 5.3 K resistor that controls horizontal linearity in the HV cage. It is stepped with additional tabs that add 500 and 1 K ohm if you move the lead coming from the horizontal yoke. I was going to replace it with a variable power resistor but it was perfect, dead on 5.3 K. In fact, I had it out of the chassis to clean out the HV cage and was ready to replace it until I measured it. So, yes I guess having a working HV resistor in the horizontal deflection circuit is rare and we are fortunate. I may change it anyway now as I'm trying to eliminate everything as a possible source of the issue.

[fumplet]

If horizontal frequency is different than horizontal lock, horizontal linerity then no i havnt adjusted that one yet....maybe under the set..will have a look. Third adjustment was vert linearity i thought

[bandersen]

No, it is horizontal lock