When you change the horizontal hold, it appears that you're actually get lock at more than one higher frequency.

That's what I was thinking too. I was pretty careful about that, but I suppose anything's possible. I'll double check my work.....

Everything seems fine....

One thing to note....I can't get more vertical out of it than I've got.

Got any more 6SN7s and 6SL7s to try? how are the dc voltages in the vertical & horizontal circuits?

jr

Tubes tested good, replacements yielded no change. I'll test circuits as time permits this evening. Really appreciate you guys sticking with me in this thread :)

I know that I am 24 hours "late for the party" but that very symptom had me pulling my hair out on an Admiral 26R12. It was on the height control. The clue which I failed to pick up on was that varying the control did not change the voltage. The set started out good. But then there was a "POP" and I lost about half of the vertical height. To me, a lesson learned. I was not familiar with tin whiskers at that time. So, you may be good to go for that.

You may want to try brushing the controls G E N T L Y to get any tin whiskers away. They can be from the terminals to the control case and drive you crazy.

In the schematic for chassis# 19A1,
There's four components in the H. osc circuit which, if they've been replaced and one were inadvertently the wrong value, could throw the frequency 'way off. They are:

C36, .01 uf. comes off pin 6 of H. osc tube
C37, .001 uf. connects between yel. and brn. leads of T4
R42, 39K goes to pin 5 of H. osc tube
R43, 39K goes to pin 4 of H. osc tube

(color code for 39K = orange-white-orange)

C36 in my Sams is a .002@600, "de-emphasis", and C37 is a .005 audio coupling cap. I'm working with set 59, folder 2, date 4/49. Matches what is in my set.

I'll just check those specific caps and resistors. Hang tight.

Okay, my diagram numbers them C46 and C47. C46 is fine, C47 is an original Micamold that I never replaced. Time to give that a try.

Translation to Sams numbers

C36 = C46
C37 = C47
R42 = R81
R43 = R82

jr

No change. Should have just done C48 while I was in there. I'll change out C48 and check those two resistors next. I'll get this yet :)

Changed C48. R81 (R42) was at 52K, R82 (R43) was at 73K. Put in brand new 39K 1 watt 5% resistors. No change in the picture.

Did your supply voltages ever come down closer to spec? What DC voltage do you read now on pins 4-6 of V13B(horz osc)?

And if the voltages are *still* too high, perhaps use your variac to reduce until they are normal and see how the horiz behaves.

Is 10 k resistor from horiz hold to the transformer ok? How about the 50 uuf cap to the sync circuit? Does the "parts set" have a good horizontal transformer if you need it?

jr

-69 VDC on pin 4, 2.44 VDC on pin 6. Still high.