Those sure are some mighty small ceramic caps. Can you notice any change in alignment after doing that work?

I used the same caps for my AMC 116T and didn't see any change. I'll let you know how these work out. They are the correct value, and 630 volt caps, and COG.

It looks like you cleaned all the old solder and lead bits from the terminal strips and tube socket terminals.
I used to have patience like that, but you still have me beat.
The kits I built, look like your work. That's why they still work well 52-55 years later.
Mostly Knight-Kits and a few Heaths.

Yeah, I clean up all the terminals where I can. Once "cleared out", I clean them with alcohol, then it is as if I were assembling the TV for the first time.

I'm all done replacing the caps and all the resistors except one in the tuner. It was buried and I didn't want to dig that deep into the tuner. The rest of the tuner's resistors, mica caps, and the sole dual disc cap were replaced.

I did a quickee test with the 14" CRT. Everything works. Excuse the quality of the picture that's because the CRT was just set in the tv and hooked up. The yoke and the focus coil weren't adjusted yet, that will come later when the final assembly takes place.

Now on to finishing cleaning up the chassis and bits to ready them for final assembly.

http://i1060.photobucket.com/albums/...psz3udn1ex.jpg

I remembered that I needed to change out the resisitors in the deflection yoke.

There are 3 of them. 1 is a 1K and the other 2 are 560 ohms. The 1K measured out to 1030 Ohms, while the other 2 measured out to 670 Ohms and 736 Ohms. They were replaced with 1W 5% resistors.

I wish I could have found a 47pf 1500 volt cap to replace the one in the yoke.

http://i1060.photobucket.com/albums/...psxbmh0dcw.jpg

http://i1060.photobucket.com/albums/...ps1sft3atl.jpg

I finished the chassis and assembled it today. there are a few details that have to be worked out, but basically its done. It's playing as I type to "burn it in". Tomorrow I'll hook up my Eico 369 and BK O'scope to start the alignment. Tonight I'll attach my NTSC pattern generator and see if I can get the picture squared up.

Then on to the cabinet.

http://i1060.photobucket.com/albums/...psxxslrram.jpg

http://i1060.photobucket.com/albums/...psu7kkj5pa.jpg

http://i1060.photobucket.com/albums/...psvf2zgwpg.jpg

http://i1060.photobucket.com/albums/...pssdzuxihd.jpg

http://i1060.photobucket.com/albums/...psobckvguj.jpg

http://i1060.photobucket.com/albums/...psykavede8.jpg

http://i1060.photobucket.com/albums/...psd2odscqi.jpg

http://i1060.photobucket.com/albums/...ps2qfsja7j.jpg

http://i1060.photobucket.com/albums/...pss8d1aap3.jpg

I have the pattern generator hooked up and this is where I am. It looks like both left and right side of the picture is blurry. What causes this?

I did have both the yoke and focus coil off the chassis and then reassembled the whole shooting match. Can a misalignment of either of these cause this?

http://i1060.photobucket.com/albums/...psggn7hmbh.jpg

You mentioned it was out of focus earlier in the thread. It could simply be the combination of a tired electron gun and it being over driven to achieve what seems like normal brightness and contrast. The further the beam deviates from center the harder it is to maintain focus. You may be able to tweak the ion trap and get the outer edges a little better, at the expense of less focus in the center.


I kind of miss the plated chassis. ;) I thought it looked really nice after you cleaned it up, not that it looks bad now, I guess I just prefer the plated look.

You also might want to double check that the dag contact spring is making good ground contact through the painted chassis.

Yes, the position of the focus coil could effect it. Also your ion trap magnet looks to be too far back on the neck. Usually they are an inch or more away from the base rather than right up against it.

Another thing to consider is that if it is a flat faced CRT it could have poor edge focus by design...Early rectangular and large screen tubes had flat faces which was quickly moved away from by makers...You see as the beam is swept the physical distance the electrons travel increases as you move away from center. Curved screens were designed to keep electron travel fairy constant at all points of the screen during scanning....Some makers tried to apply sweep derived AC to the focus on flat faced tubes to reduce that effect, but on sets that lacked that you kinda have to live with what you have (which usually involved setting focus for a compromise between edges and center).

Kevin,
I'll play with the ION trap a bit to see if it improves.

The plated chassis had a lot corrosion, not rust, but corrosion. I tried to rub it off but then that area was "polished" and still had the discoloration from the corrosion on it. I think at one time somebody spilled something down into it or most likely sprayed something into it.

Good idea! I'll clean that area up to make sure I have good contact.

Bob,

I'll try and re-position the focus coil. I'm guessing the it should be centered on the neck of the CRT when the adjuster is also centered?

When I got the TV the ION magnet was positioned all the way back. I'll move it forward to see what happens. though I did move it around when I first powered it up.

Thanks Tom for that info. Maybe there might be a better compromise.

Guys, thanks for your comments. I'll try what was suggested. Your help is appreciated.

Well, I just lost HV and now no raster. I'm getting about 600 volts at the 2nd anode connection. I was messing around with the H freq. adjustment and then looked up and a dark picture tube! I tried to "undo" the adjustment but that didn't help. There was no popping sound or anything.

If you have a scope check the osc. waveforms and frequency against sam's. A guick check to see if your osc is working close to right is to check the grid voltage at the H out tube.

If that 'corrosion' was green/white-ish green(sometimes yellowy) and fairly even then it is not corrosion, but rather Cadmium plating. It is natural for cad plating to turn green-ish with age, and it does not hurt anything when in that state. Best not to polish cadmium...It is rather toxic. I always leave the metal on cad plated chassis alone.

Tom,
This chassis didn't seem to have the CAD plating on it. The corrosion consisted of many, many small dots. It wasn't an even coating. Some areas even left some small pits in the metal.

I really like the appearance of your painted chassis, but I was always afraid that paint may interfere with good chassis ground connections. And most (radio) restorations with a painted chassis looked bad because it left all the other visible pieces looking old/cruddy. I wonder what will happen with those tubes so close to the high voltage cage. One looks like it has got only 1/8" clearance. Are they going to cook, burn, or blister your paint job? And the possible smell...

.

I've done some troubleshooting.

I did a voltage check on the 3 tubes V15 a 6SN7GT Horizontal AFC and Osc., the 6BQ6GT Horizontal Output, and the 6W4GT Damper tube. Here are my findings. 2nd values are my readings:

6SN7GT
1 -2.8v -25v I thinks SAMS made a mistake here. Riders shows -40v.
2 100v 105v
3 -22v -16v
4 -60v -59v
5 235v 190v

6BQ6GT
4 140v 128v
5 -8.6v -8.6v
6 220v 190v
8 5.6v 6.3v

6W4GT
3 320v 250v
4 320v 250v
5 220v 190v
6 310v 255v

The voltages don't look too bad. Most are a little low.

I did hook up my scope to the grid (pin 5) on the 6BQ6GT tube and here is what I got:

http://i1060.photobucket.com/albums/...psnwuyb8u1.jpg

I then checked point "C" on L19 per Sams on adjusting the Horizontal Sweep Circuits. This is what I got after I adjusted "B3" on L19.

http://i1060.photobucket.com/albums/...ps44twtgse.jpg

I don't know what the frequency was but the time dial was set 10us.

http://i1060.photobucket.com/albums/...pshndtcaft.jpg

Here is a picture of the schematic showing the area:

http://i1060.photobucket.com/albums/...psoxqorgru.jpg

I also ohmed out the fly-back and it checked out pretty reasonable.

EDIT! I remembered that I can hook up my frequency counter to my O'scope and I then adjusted the Horizontal Frequency "B2" to get 15,734 cps.
Another EDIT! I added the voltage on the 6BQ6GT Pin 8.

Is there any way to test what's going on with the flyback? Like seeing the voltage from the 6BQ6GT plate cap? Like measuring the voltage there? Everything I've checked so far checked good. I'm getting about 3Kv right now and have a faint raster. So I am getting some HV, just not enough. I don't have a flyback checker. How can I check the door knob cap? I'm trying to find out why my HV is so low.

Thanks for your help.

Your horizontal drive signal basically looks good, but your boost voltage is 70 volts low originating at pin 3 of the damper, which is why some of your other voltages are low. What is your scopes volts per division setting when you measured the signal at the grid of the horizontal output? Have you by chance tried another damper and HV rectifier?

How does your 210 volt supply read at the fuse(M2)?

[edit] Don't forget to make sure your dag coating is grounded good, as I don't see any other HV filter cap going to ground.

Have you subbed the 6BQ6 yet? You van sub it with a 6DQ6 in a pinch. The 6W4 can be subbed with 6AX4 or 6AU4.

You failed to list voltage on pin 8 (cathode) of the 6BQ6. But on the schematic you indicate 5.6V. Are you still getting 5.6V there? If not, the tube is not conducting (or if it's too high, the tube is conducting too much).

Also try this - with the plate connector disconnected from the HV rectifier, use an insulated screwdriver and see if you can draw an 'air arc' from the connector. If the fly is putting out, you'll get an arc of a quarter inch or more. But don't short it to ground.

We'll start with this one first.
I added the voltage on pin 8. Listed voltage is 5.6v and I measured 6.3v.

Will do that arcing test next.

I have subbed the 6BQ6GT and the 1B3GT. Not much change in the HV. Actually what is installed is a 6DQ6GT. When I had good HV, I subbed a NIB 6QB6GT and the HV was lower, so I put the 6DQ6 back in.

I also subbed the 6W4 with no help.

I got 190v at the fuse. Earlier I cleaned the dag grounding wire mount and just ohmed it out and it shows zero ohms from the wire and from the dag.

I just tried the HV rectifier cap connector and I got a very healthy purplish 1/4 to 3/8 long arc.

So it looks like my problem might be with the 1B3GT or its connector. There are 2 resistors under the connector.

Could the door knob cap be bad?

I think the volts per division were 5v.

I tried another damper and HV rect.

Where does the boost voltage come from? It looks like it might come from the flyback. What would cause it to be low.

Just trying to understand and get the voltages where they should be.

There's a slight possibility it could be bad and dragging the HV down, just disconnect it to test, the CRT has a Dag coating and performs the same function so it shouldn't be essential.

Eric,
I just tried what you suggested and disconnected the lug from the bottom where the white/red wires are connected. When I powered up the set, all I got was some arcing sound from the base of the HV rectifier. I moved things around but each time I got the arcing sound so I put it back together. Still only about 3Kv.

BTW, I used my multimeter to measure the door knob cap. It measured out to 630pf but is listed as a 500pf cap.

Everybody I do appreciate your help with this stubborn problem. I'm sure we'll get it fixed. I just wanted to say thanks for your help.

If you darken the room, it may be possible to see where the arc is.

Have you changed or tested the 1M resistor that's mounted under the 1B3 socket? Those often go very high in value/intermittent, or open. It's the 1M shown in series with the HV lead on the Sams schematic.

The boost voltage is derived by combining the 210 volt supply with the voltage of the lower flyback winding during horizontal retrace. It's a free source of energy during retrace, and so provides a boost to the 210 voltage supply that gets filtered and used for some circuits that work better with the higher voltage.

That was my oversimplified explanation of how boost voltage is generated. It's the best I can do while drinking Jack and Coke at 12:30am. :D

Kevin,
The the 1meg resistor was changed and still measures 1 meg.

Thanks for the explanation for boost voltage.

Just might do that if I have it apart again.

Well I changed out both resistors (R85 and R86) that were in the connector base of the 1B3GT and used heat shrink everywhere to assure no problems.

I then powered it up with the door knob cap (67) out of the circuit and I still have about 3Kv. I then reassembled the connector and cap and the same thing, 3KV.

I substituted the 1B3GT and still the same thing. I substituted the 6W4GT damper and still the same thing.

Right now I'm at a loss as to what could be the problem

I am thinking of removing the white/red wire that feeds to #1 on the yoke assembly to isolate the yoke assembly. Can I do that without causing other problems?

http://i1060.photobucket.com/albums/...psbrnepcmv.jpg

http://i1060.photobucket.com/albums/...pstge3mkyx.jpg

I removed the white/red wire to isolate the Horizontal wings on the yoke and then checked the voltage.

With the white/red connected 205v
With the white/red wire disconnected 245v

I disconnected the wire from one of the terminal on the flyback. #8 on the schematic.

Still have to do the Vertical windings.

Your HV rectifier socket looks charred on one side. Or is that dark black some liquid tape? Or possibly it's just the lighting. It might be normal for the voltages to come up without the load of the yoke on the horizontal fly winding.