Admiral 20X12 restoration

[bandersen]

I swapped out the 6SN7 hor. oscillator and tried another 6BG6. That helped. I also replaced the 47 ohm 6BG6 grid resistor which had drifted up to about 58. That helped too.

Then I tested the CRT. Emissions are OK, but the life test is weak and I had no cutoff control with bias at -52v. If I dropped it to -36v, I got some response when rotating the cutoff control but still not right. So I used the rejuv. and auto-restore functions as indicated. That helped, but the cutoff is still weak.

I'd try swapping out the CRT, but someone did a sloppy base repair and I can't slide it through the yoke, etc. without filing it down


At any rate, here's where I'm at. The picture is brighter and the bandwidth looks good. However, I have some horizontal tearing. I guess I'll do some more checking of the sync and horizontal circuits.

[VintagePC]

If they used straight up epoxy for that repair, it should peel off the outside of the neck without too much force - it doesn't stick well to smooth surfaces like glass or plastic, unless you rough them up a bit first.

[old_coot88]

Originally Posted by VintagePC

If they used straight up epoxy for that repair, it should peel off the outside of the neck without too much force -

YIKES No!If that epoxy is engulfing any of the wires where they emerge from the glass (which looks to be the case), any movement of the epoxy will likely break them off. Grind the epoxy down flush gently.

[VintagePC]

Originally Posted by old_coot88

YIKES No!If that epoxy is engulfing any of the wires where they emerge from the glass (which looks to be the case), any movement of the epoxy will likely break them off. Grind the epoxy down flush gently.

If the base is fitted properly to the glass, there will only be a very thin seam where they meet- and that will break or can be cut very easily without disturbing the epoxy under the cap.

[old_coot88]

Yeah if the base were intact that would be true. But there looks to be a BIG chunk broken out and missing, and the resultant gap rather sloppily filled in with epoxy. 'Least that's the way it appears to my enfeebled eyeballs.

[Zenith26kc20]

I noticed that your Admiral in one of the pictures has the picture off center. Mine is like that too. My focus/centering coil is all the way and, it will fill the screen but still is off to the left. Are you able to get decent centering or is this a trait of these TV's?