A real train wreck of an Admiral 19A11

[Kamakiri]

Believe it or not it locks solidly, it just looks like crap. I've been distracted by a CTC-5 Stanwyck lately plus an Air King A-1000 came my way. I'm thinking it's got to be in the boost....but I'll have to get back in and check.

Plus customer stuff coming out of the woodwork. Last week it was a Scott Stereomaster amp, this week it's a 1970 Zenith color console. When it rains it pours....

[earlyfilm]

Originally Posted by Kamakiri

Believe it or not it locks solidly, it just looks like crap....

Tim,

On the vertical fold in center screen, try popping in a different 6SL7 and check the voltages on that tube and the vert osc. The 6SL7 is a push-pull circuit and both sides should be close.

Warning:
Rider screwed up plate voltage on the 6SL7 with plate pin 2 (250v) and the other plate pin 5 (2v). Duh!

Both 2 and 5 should have about the same voltage, 250v for Rider and 220v per Sams. Other Rider voltages indicate a higher line voltage than Sams.

That fold could also be caused by a minor signal overload, but that usually would cause too high contrast.

Does the fold stay still or does it slowly move up or down?

If you finally got a 'scope, now is the time to use it to compare wave shapes in the vertical with your other 19A11 or the shapes in either schematic.

Edit:

Oh thinking about this thread overnight, I'm more inclined to think Chris's thoughts on the vertical frequency being off is more likely. The unusually wide vertical sync pulse visible at the top of the screen is the clue. I'd say it is off by a harmonic, like running 90 fps instead of 60 fps and this is a vertical frequency issue, and the photo shows a sweep overlap and not a sweep fold. (A moving image clip instead of the still image would better show this.) If this is the case, then check for errors in the vertical oscillator tank circuits.

If this set had electromagnetic deflection, instead of electrostatic, the yoke and/or vertical output transformer would have been buzzing rather loudly in protest.

James

[Kamakiri]

Got it!!

There was a 2.2 meg resistor where a 3.3 meg should have been.....vertical oscillator plate resistor (R61 in the Sams)

Now, the final problem is width. I also have a Tele-Tone TV149 wih inadequate width that I have to fix as well. What's the secret with these width issues in electrostatic sets??