Picked up and Admiral 20X122
 

I found this on my regional Craislist for $50 on Thursday. I originally decided the 3 1/2 hr trip[ each way as not worth it, but I emailed the guy Sat morning. He still had it, and I was on my way from south GA to northern South Carolina by 1PM yesterday.

The seller immediately assumed I was going to "flip" it and resale it for a profit asking "How much was I going to make on this set?" I assured him that I was a collector and was going to restore it and display it in my house along with my other sets. I had brought a buddy with me who restated that I have a collection of old TVs and radios in my house.

Anyway, the seller said it hadn't been powered up in 30 yrs. He said the last time he used it, he let it sit for about a yr before trying it again. By then it wouldn't work. He said he reached in the back and was almost knocked off his feet. It's been sitting idle ever since.

The cabinet is in excellent shape, no cracks, just a few minor scratches that Novus #2 should take out. All I plan to do right now is just check the CRT.

I guess it at least had high voltage at that time. :D

Yup, I'd make room for one of those.

Nice find and the price was a steal. You're lucky that it has the elusive metal back on it. That piece will often get more than you paid for the entire set - if you can find one.
After decades of passing them up I finally got a restored one a few months ago (for SUBSTAINTIALY more than you paid!) and am so impressed by it. One of my favorite pieces of my entire collection. As expected from Admiral, great solid performance too.

Every collector should have one of those, and you got it for a great price.

By coincidence, I'm working on one of the look-alike models (24A12) right now.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

I LOVE the Bakelite ones, a WHOLE lot more than the kinda Weird "Flying Buttress" versions..

Those are great performing sets and you stole it! That set is an easy set to restore and the picture is surprisingly very good. Shine up the brass around the knobs and it's a very sharp looking little TV. Great find! Attached is the picture of mine that I restored a couple of years ago. I've got a 14 rectangular bakelite Admiral console still on my to-do list.

I would drive 3.5 hours each way to get one of those for $50, too. Nice find!

I'm waiting on parts for the Hoffman I'm currently working on, so I decided to try a slow power up with the Admiral on the Variac tonight. Surprisingly, I ended up with adequate sound, but no raster, just like the seller said when he last tried it 30 yrs ago.

I noticed the 6BG6 glowing blue, so I powered it down and checked that tube as well as the fuse. All checked ok. I checked the 1X2, an my tester showed bad, so I tried another one. Same results. 6BG6 still glowing blue. Have not put the HV probe on yet.

AT least the set is not in too bad of shape. Funny thing. I posted how the seller stuck his had inside and was knocked backwards. The "Danger High Voltage" label is still on the set. I guess he ignored it.

If the entire interior of the 6BG6 is glowing blue (not just tiny, well-defined blue streaks on the glass), the tube is gassy, i.e., shot. Irrespective of how it may read on a tester.

Lucky guy. I have an imcomplete one that I got working, and, it broke down. They do show a very nice picture.

I've got too many other TV projects going now to start on another, but I couldn't resist the urge to pull the chassis out of the cabinet and have a look. It appears unmolested. I think I can only see one capacitor that's been replaced during the life of the set.

I'm waiting on parts for my Hoffman, and just about to finish up my Emerson portable with the picture jitter; so I may go as far as replacing a paper cap or two in this Admiral before I set the chassis back in the cabinet.

I didn't have anything to do yesterday, so I decided to start recapping this set. I've got most of the paper caps replaced and 2 of the 3 electrolytics done.

I'm still getting good sound but no raster. My HV probe shows only about 1KV of HV I started checking voltages in the horizontal section and found them way off.

V15 the 6BG6 is as follows 6SN7 Horiz Osc V14
Pin SB I have Pin SB I have
1 -.5 0 1 -3.1 -10
3 9.6 2.4 2 100 38
6 190 105 3 -18 -6
8 260 221 4 -55 -24
5 190 120
Have tried another 6SN7 and another 5U4.

My voltages got messed up when I posted, so I will redo it.

6BG6 Pin 1 SB -.5. I have 0
Pin 3 SB 9.6 I have 2.4
Pin 6 SB 190. I have 105
Pin 8 SB 280. I have 220

6SN7 Pin 1 SB -3.1. I have -10
Pin 2 SB 100. I have 38
Pin 3 SB -18. I have -6
Pin 4 SB -55. I have -24
Pin 5 SB 190. I have 120

Ok, I have replaced everything in the horizontal osc & output sections with the exception of C71 (7.5pf @ 1500V) and the 500pf doorknob cap. I still have no high voltage. Most positive DC voltages on both the 6SN7 and 6BG6 tubes are way low except pin 8 on 6BG6 is right (about 270V). I have no negative voltage on the grid of the 6BG6. Replaced R78 and R79 and C54. I don't hear the horiz osc running and adjusting the horiz drive timrrer screw has no effect.
Any ideas?

Thanks
Doug

Success
 

I finally got a picture this morning. A 75K ohm resistor in the horiz osc circuit was open. I'm getting a good pic now but with vertical issues. It looks like I'm getting a double pic and it will not fill the screen vertically. I'll keep poking at it.

Your actually not too far from the correct vertical height. Keep in mind that the top and bottom of the CRT should be covered by the mask for a 4:3 aspect ratio.

What I seem to have, I think is called Vertical Flopover. You can tell from the pic, that the man's head is at the bottom of the screen while his chest is at the top. Is this a vertical problem or a sync issue? When I 1st turn it on, the horiz will not sync either, and have to adjust the horiz frequency. Now, pin 1of the 12AU7 Vertical Amp should have between 80 and 148V. I only have 38V.
That pin goes to one side of the Vert Blocking Osc Transformer. Pine 2 goes to the other side and the voltage is ok.

Your vertical osc is running at double frequency. I've dealt with a set with that issue before.

I just replaced the vertical osc transformer and all of the resistors in the vertical circuit. Nothing has helped. Vertical osc is still running at twice the frequency. All voltages are fine except pin 1 of the vertical 12AU7. I should have around 90V and I only have 43. Only thing going to that pin is one side of the vert osc transformer.

What would cause it to run at double frequency?

Did you accidentally replace a cap with one 10X or 0.1X rated value?....That would do it.

I just finished replacing the vert height control and the last mica cap in the vert circuit. This made no change. Vert osc still running too fast. I check all caps, and they are correct. I'm at a loss now of what to do next. Any ideas?

My case (1953 Zenith) was likely caused by a bumblebee cap being listed a power of 10 off in the schematic VS the parts list of the sam's. I did not have other caps at the time, but did have resistors, and a resistance decade box....I decade box engineered my way out of that mess, and you can too.

I'm being to thin it's a sync issue instead of a vertical issue. As I noted sometimes when I 1st power on, the horiz will not sync until I adjust the horiz freq at the back of the set.

I use a copy of the 1956 edition of Sams Television Servicing Guide. It called that symptom of he vertical osc running too fast as "Vertical Flopover" and it's listed in the chapter dealing with sync problems.

I checked voltages on the 12AU7 sync amp tuibe. Plate, Pin 1 SB 38 V. I have about 150, and pin 2 SB -1.5. I have about -10. This is with a signal applied. With no signal, the voltages are correct. The .05 cap between pin1 and pin 8 (which is also off) has been replaced, but I put another one in tonite just to make sure. I did the same with the .01 coming off pin 2.

If there is horizontal sync noise in the vertical that might cause it to freak out that way, but if it is just a weak sync problem then you should be able to get a slowly floating near synched picture with the vertical hold control.

No harm tuning the sync up, but if all component values in the vertical are correct and it is still doing that you will probably need to turn to decade box engineering.

Maybe you could try comparing the vertical cap values listed in Sams with those in Riders TV4. The ETF has both schematics available for download.

I've gone thru both suggestions. I printed out the Riders schematic and compared it to the Sams in both the vertical and sync circuits with no differences.

I do have a capacitor & resistor substitution box like Electronic Memory suggested. I subbed the caps in the vertical circuit and even did some experimenting with the box like changing a .1 to a .01. Nothing cleared up the vertical oscillator.

Here are 3 pics at various settings of he vertical hold control.

I just replaced the last of the resistors in the sync circuit, and no change. I even disconnected the replacement vert osc transformer and swapped the wires to make sure I hadn't hooked it up backwards.

I have checked and rechecked my work from the 12AU7 sync amp, thru the sync clipper and thru the vertical amp tube and all parts are correct. The only voltage difference is on pin 1 of the vert am. I should have between 80 nd 148 volts, and I have 44. As of now, I've done all I know to do.

I had the same problem on my RCA 721ts I just finished. It turned out to be a dirty vertical hold control. Spray it with contact cleaner and rock vigorously from one end to the other.

If it ain't dirty controls, then it's probably time for some decade box engineering....Don't worry if you've never done it before, I never did it before when I used it to fix my set, and I managed to figure it out (back in highschool).

SUCCESS!!!!!!!!!!

It was a dirty vertical hold control. Man, do I feel stupid that it was something that basic that I thought I had cleaned when I 1st started restoration.

I've got to get everything tweeked and make a decision if I want to put the modification on to eliminate the retrace lines.

Once I get it back in the cabinet, I'll post more pics.
Thanks again for all the help.

After a couple of forehead-slap experiences like that, I put cleaning of tube pins & sockets, plus all controls, at the very beginning of every project's to-do list.

http://antiqueradio.org/FirstStepsInRestoration.htm

Regards,

Phil Nelson

Awesome, good to hear!

To hopefully make you feel better, I worked on an Admiral 26R12, the exact type of set I had as a kid; first set. It was working fine after replacing all of the paper and electrolytic capacitors. Whilst still on the bench, I heard a loud snap/pop and was unable to locate where it came from. My vertical linearity was now a mess. The height control also had no effect on the picture (glaring clue that I unfortunately didn't pick up on).

Long story short, tin whisker on the height control most likely. Adjusting the control did nothing to the voltage. I cleaned if off with a brush and all was now fixed.

So, all that I can say is, "Welcome to the club".

Finnised, I Hope.
 

Here it is back together in the cabinet.
Thanks for all the help. This one has been a learning experience for me.

Nice job. It looks great. It's one of those sets that I would recommend for someone who only wanted one vintage TV. A great performer and one of the the coolest looking artifacts of the '40's!