Good goin' bro. Still kinda curious why there was no plate voltage on the H.osc before.:headscratMaybe there was a production change so it runs offa Boost instead of B+ (?)

Equally curious how the vertical Osc. was running before, with no boost.

Not sure, but I could hear it, and the frequency did change with the vertical hold.

Doorknob cap is fine, as is the 470 MOhm resistor on the 1X2 (Sams shows it to be a 1 Meg, but....anyway). Next, I'll clean the snot out of the tube pins and tube socket.

I guess Sams does show that some version had the V Osc. running off of B+. They show the alternative path with a dotted line.

470 M, as in mega ohms? Or is that the really really ancient abbreviation for one thousand? ;)

470K. I typed it too fast :drool:

But hey! I gots a raster!!!! :yippy:

I can barely get any sound at all on frequency and it looks like the IF's gonna need work, but this is a major leap forward, thanks to you guys!!!

Now, next question....source an Admiral replacement for that linearity coil, I assume?

Sweet!

I can cross that Lin coil to a Thordarson. But something tells me they were all pretty generic from the period.

Thordarson WC-14.

http://www.ebay.com/itm/Thordarson-W...IAAOSw8-tWZhH1

Hopefully the filter caps had enuff headroom for that sustained high B+.

Just enough. I went 450 across the board....

Mine! :D Thank youuuuuu!

Well, the coil's in. Hm.

Very weak signal, very little contrast. In fact, I may have tweaked something in the wrong direction, as now when you turn up the contrast, the picture goes negative....

Any chance you could post a vid of what it's doing? That horiz breakup suggests one (or both) of the slugs in the H.freq. can (L17) might have been futzed with.

It's really hard to show. When I installed the new coil, I set the frequency as I usually do when it's off on a first powerup.....keep turning....4 horizontal images, 3 images, 2 images, boom.....done. In this case I got it as close as I could, but the image on screen is so washed out that I can't get a clear shot of it. This is what it looks like with no signal. With really weak sound and picture when it has a signal, this to me shows an AGC problem, first and foremost....unless I'm wrong :)

Do you have a scope to check the H osc. wave shape? The raster pic from your previous post makes me think the other slug that sets wave shape is miss-adjusted.

This may sound wacky, but I tend to adjust synchroguide oscillators with a scope. First I scope a composite video source and get 2 sync pulses on the screen as a reference H sweep time, then I adjust the synchroguide to match that time and adjust the peak and mound to about the same height....Might be over kill, but in early color sets with that circuit it helps me feel confident about the H sweep system.

Doesn't sound wacky, it sounds very educated. Far more so than I am, I'm afraid.

Don't own a scope, don't know how to use one, don't know what I'm looking at even if I did. I'm a heck of a TV mechanic, but as a technician I leave a lot to be desired :)

But that would have no effect on the AGC anyway, would it? Obviously the issue's still gonna be there, but I can't get enough gain to really get much on the screen as it is.

If it uses keyed AGC (I'm not familiar enough with this chassis to say) horizontal issues will affect the AGC....If it's just regular AGC the two are more autonomous.

No keyed AGC. Uses a 6AL5 dual diode as video det/AGC. One diode detects video, the other is for AGC. If I recall correctly, I think there's like a 1.5v delay on AGC line.

So, after replacing a resistor outlined in this thread:

http://www.videokarma.org/showthread.php?t=265914

This is what I've got.

Width control does nothing. There are only two out of the three terminals used on the contrast control, and it looked as if someone did some soldering there. Then I figured it out.....

The contrast control has a dead spot on the far clockwise position, and now that I've got that resistor replaced and the contrast control actually does something, I realized that someone along the way wired in the contrast control backwards so that the counterclockwise position is maximum gain......

By adjusting the horizontal frequency, this is as close to a single image that I've managed to achieve.

Looks like the H.osc frequency is running 'waay high and locking to an integer of 15,750 Khz.

Looks to me it's locking onto 1 1/3 times the proper horizontal frequency. Maybe a frequency setting coil in the oscillator section is too far out of adjustment?

The bottom of the horizontal oscillator's just a mess. Here's a shot of that, and another shot of the section. The orange drop was done by the last person that worked on it, I should probably change it out just because......

If the osc. coil is out of range I'd check the resistors and try replacing that orange drop...If that fails see if adjusting the other slug of the osc. can gets you anywhere.

Have you tried adjusting the horiz. range trimmer, designated B2 in Sams? It's located on the rear chassis apron, next to the horiz. drive trimmer (just to the left of it).
Also there's two resistors, R75 and R76 (68K and 120K respectively), coming off either end of the horiz. hold control. Either of those being off value will affect the range.

What value is printed on the Orangedrop cap? Is it .002 mf?

I didn't try the range because I was assuming that it was a frequency issue.....can't hurt though :)

The orange drop was a .002. I changed them both, no change in performance. I'll check the resistors tomorrow. I'll get back on the 8TS30 as well :)

It means `frequency range`, like a coarse adjustment, with the H.hold being the 'fine adjustment'.

It looks as though sumbody was working on this problem at length, then gave up on it when that Lin coil blew.

Well, I've spent time over the last couple weeks on this set and got basically nowhere. This morning I got up at about 3:30 AM after falling asleep at about 8:30 PM last night, I had a full head of steam and decided to tackle this set, do or die.

I disasembled and tested everything in the entire horizontal circuit, found one missing cap on the width coil (this set was pretty botched up before I got it), and no change. After testing about a dozen resistors and replacing a couple that were way out of tolerance, still no change.

Then I noticed a couple green spots of corrosion on the back side of the width coil, where I couldn't have seen them before. Looks like a couple turns are shorted....which would explain why the turning the width coil does absolutely nothing. That, and the fact that the horizontal lin coil, which sits right below it, was corroded and open, leads me to believe I need a width coil. Spec on the Sams is .1 ohms, this one reads about 1.3 ohms.

I'll pick this up after I get one......

Good luck with it. Sometimes you get those sets that just play flawless with a re-cap and others have all sorts of issues. I guess it's the conditions they were stored in that determines that.

When you're talking 1.2 ohms error, make sure your meter was able to zero first, and that the terminals on the coil are clean(maybe re-solder them) It doesn't take much contact resistance and you end up with a false reading.

Even when working correctly, the width coil has very little effect. From one extreme to the other it will change the width maybe an inch or even less. The with coil is in parallel with the flyback coil and used to tweak it's characteristics.

BTW that photo you posted earlier of the bottom of the hor. osc. circuit is stock. Admiral made really wired it that way with three resistors connecting together in mid-air.

Yep, I figured that out by the schematic. As I said, I tested every resistor in that entire string. Since the width control does nothing and I have inadequate width, along with the resistance of the coil, I figured that would be the next step. Terminals were definitely clean, as I de-soldered and cleaned the ends of the wires to the coil.

These sets are never this difficult! :)

Welp, she's working great now!

The problem turned out to be a simple one. Whoever was futzing around under the 6BG6 (probably before I was born), cut a cap out of it that I couldn't even see. Looks like someone back then was testing things and just gave up. That, and the width coil out of a parts set (thanks bgadow!) brought the set back to life! :)

Horizontal lin's a little off, but I'll play with that after a little usage.

And finally, another tough dog is done. Whew.

Well done Tim!!! Perseverance! !!

Kudos to you Sir. Good job! :rockon: Of course I'm curious which cap it wuz.

It was a .2 uF 200V cap anchored to a dead pin on the 6BG6 going to the ground on the filter can closest to the tube......