View Full Version : A real train wreck of an Admiral 19A11


Kamakiri
08-28-2016, 06:26 AM
I just love working on something that was repaired by someone who "really knew what they were doing". Enter this Admiral 19A11 chassis.

Here's the beginnings of the story.....

See the cap I'm holding in the first shot? Apparently it was "too tight" for the guy to squeeze his 55 watt Weller blowtorch of an iron in between two adjacent tube sockets, so he wired the cap all the way across to the other side of the chassis and zip tied it into place on the tuner body with no insulation. Doing it once is bad, doing it with half a dozen is a freaking mess. See that Sangamo cap in the bottom right? There's another. I said "screw it", and started cutting zip ties and moving the jungle of wires out of the way to see what this guy was thinking.

And I know he was using a 55 watt Weller because not only are there scorch marks all over everything where he couldn't get it to fit in to do the work, but it melted the pins off of some of the tube sockets where he tried to desolder the wires, and he ended up tacking on wires to the pins of the tubes. And of course all of the components that those were attached to were relocated elsewhere.

As I begin to straighten out all of the cross wired circuits and careless capacitor replacement (20 and 30 uF? Let's put in all 47s), I'm beginning to understand what's going on here. First, the guy cut out and tested caps several at a time, then stuck them back in or replaced them by looking at the Sams, and got several values wrong, and grounded them where he felt like. But that's not the worst....

I'm redoing a bunch of the wiring to the filter can and setting everything right, when I notice something that I didn't see under a mess of wiring before. See that hole in the chassis on the far left in the second pic? That's where the horizontal size control USED TO BE!! Somehow the guy tried to wire around it and jumper connections to both the vertical size and horizontal hold control to bypass it. I have NO idea HOW this set ever worked, but I was told it did.

Kamakiri
08-28-2016, 06:30 AM
After a lot of work, here's where I'm at today. In order to get this far, I restored another Admiral 19A11 and used it as a blueprint going from connection to connection, tube pin to tube pin straightening out all the wiring and components. This has been a three month on and off project.

Sound is perfect. Any ideas on where to check from here? Bearing in mind that the set could have any one of a number of issues...including something hooked up incorrectly or a wrong value somewhere even though I took painstaking care to make sure everything was correct.

Electronic M
08-28-2016, 07:36 AM
Probably was a moron more so than a big iron...I've been using a 150W iron as big around as the average brautwurst (1.5 inch back from a pencil thickness tip) for a year or two and do MUCH better work with it...Granted I keep a much smaller iron for real tight spots (like that bundle of caps near the tuner in a 630) and SS work.

John Marinello
08-28-2016, 11:08 AM
Low B+ or boost??

dieseljeep
08-28-2016, 08:44 PM
Probably was a moron more so than a big iron...I've been using a 150W iron as big around as the average brautwurst (1.5 inch back from a pencil thickness tip) for a year or two and do MUCH better work with it...Granted I keep a much smaller iron for real tight spots (like that bundle of caps near the tuner in a 630) and SS work.

I just restored two TV's and an old radio, using my Weller D-440, 145/210 watts that uses the same tip as the 100 watt Wellers. That model, was always my favorite gun. Weller quit making it several years ago. :sigh:

ChrisW6ATV
09-05-2016, 08:57 PM
After a lot of work, here's where I'm at today... Any ideas on where to check from here?
In your picture, I see a vertical problem (off frequency, and maybe no sync?) as well as possibly a width problem.

Since you have two of these sets, I would try the relatively easy test method of comparing scope views and voltages (as well as maybe resistances) in the vertical circuits first.

Kamakiri
09-06-2016, 03:45 PM
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
09-06-2016, 06:59 PM
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
09-13-2016, 01:21 PM
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??

MRX37
09-13-2016, 08:29 PM
Here's the beginnings of the story.....

See the cap I'm holding in the first shot? Apparently it was "too tight" for the guy to squeeze his 55 watt Weller blowtorch of an iron in between two adjacent tube sockets, so he wired the cap all the way across to the other side of the chassis and zip tied it into place on the tuner body with no insulation. Doing it once is bad, doing it with half a dozen is a freaking mess. See that Sangamo cap in the bottom right? There's another. I said "screw it", and started cutting zip ties and moving the jungle of wires out of the way to see what this guy was thinking.


:worried:



And I know he was using a 55 watt Weller because not only are there scorch marks all over everything where he couldn't get it to fit in to do the work, but it melted the pins off of some of the tube sockets where he tried to desolder the wires, and he ended up tacking on wires to the pins of the tubes. And of course all of the components that those were attached to were relocated elsewhere.


:eek:



As I begin to straighten out all of the cross wired circuits and careless capacitor replacement (20 and 30 uF? Let's put in all 47s), I'm beginning to understand what's going on here. First, the guy cut out and tested caps several at a time, then stuck them back in or replaced them by looking at the Sams, and got several values wrong, and grounded them where he felt like. But that's not the worst....

I'm redoing a bunch of the wiring to the filter can and setting everything right, when I notice something that I didn't see under a mess of wiring before. See that hole in the chassis on the far left in the second pic? That's where the horizontal size control USED TO BE!! Somehow the guy tried to wire around it and jumper connections to both the vertical size and horizontal hold control to bypass it. I have NO idea HOW this set ever worked, but I was told it did.


http://www.milhist.net/images/2000YardStare.jpg