I'm thinking of buying this Admiral
 

https://chicago.craigslist.org/chc/a...300445685.html

The case looks nice. I don't know much about this stuff.

Thoughts?

Looks well-worth $60 to me...even has the original back! Restored they're pretty good performers.

It's a 1949 model 12X12 and well worth the price.

It has a 20Y1 chassis with a 12LP4 CRT. Seems to be less common than the earlier 10" version. Nice to have the metal back but the control door is missing and they are hard to find. Mine is missing too.

Here's what it would look like: https://www.pinterest.com/pin/457537643370097998/

NEVER have seen a working model of these.

I had one. CRT was almost dead so I had to turn the lights off to watch. Mine did have a good door though. Sold it to Dave (Dieseljeep) a few years back...I sorta miss that TV.

A few years ago, I did a slow variac power-up of mine, which still has most of its original parts, and it worked ok.

http://www.videokarma.org/attachment...1&d=1254636306

Gotta give it a full recap job, one of these years. :D

jr

I saw that on CL too!:D I want it as well, but I'm not going to get it. Not interested in goin through Chicago for it. NOPE!


Shouldn't be hard to restore. I restored my 20X122 in exactly 1 week. Works great and has a great pic.

Wonder WHAT was the deal on the funny-shaped CRT ?!?

It's actually a pretty good compromise between the "double D" mask and the "porthole" presentation. For a 12 inch round jug the vertical display size is increased by about 1/4 inch... not much, but I think that it makes for a more pleasing display. Compare to the 12" Philco next to it.

https://farm5.staticflickr.com/4348/...a86c07_z_d.jpg

IMHO, pretty nice.

jr

Welp, I pulled the trigger.

I gotta say, the case is near immaculate. It has like a grand total of 2 small scratches that you can't even see at 5 feet away. The safety glass is plastic, and amazingly that's scratch-free, too. Inside there's a lot of dust, a mix of tubes, what looks like the original crt, no brightener, and all the pots and switches are free. It has the original metal back cover, and even the power cord, which is strangely still supple and intact. Oh, and it has this weird adjustable built-in antenna, and (I think) an adjustable electromagnetic focus ring? O_o

Sadly the crt tests near-dead.

I tried to bring the set alive on a variac and a wattmeter, but it was very quickly apparent that it wasn't having it. So here's the next question: do you think I could get away with just replacing the filter caps and making sure all the tubes are ok, in order to see if the crt will give me something? You know, before I go all the way and recap the whole thing?


Also, jr, I might have to hit you up for pictures of that front door thing, at some point in the future. :3

Very cool!! Let's see some pictures when you get the chance.

Ya might be able to 3D print that door. It is 2017 after all.

How long did you leave the CRT on? It might wake up and if not it might rejuvenate.

Sounds like an ion trap magnet, if it's an adjustable circular gizmo around the CRT neck. You can read about that and many other wonderful details in the Rider and Sams service manuals available at the ETF archive (scroll down to 20Y1):

http://www.earlytelevision.org/tv_sc...s_admiral.html

Sure, that's one approach. If your CRT is truly a dud, you still might not see anything, but at least you could measure key voltages and compare to the service manual values, and discover other things depending on what test equipment you have.

Also, as mrjukebox160 notes, some CRTs that look dead at first will "wake up" and show higher emission if you leave them on the tester for a while.

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

Some comments.

1. The focus coil can be tilted by moving a lever arm to position the trace... that is the odd arm sticking out of the back of the set.

2. You could try a power-up with the rectifier (5U4) removed, to see if the excessive power draw is caused by the filter caps...you should be able to light up all of the (good) tube heaters, without drawing excessive wattage.

3. Sure, I should be able to get halfway decent close-ups of the door with this iPad.

4. For sure, try an extended "wake up" of the jug.

jr

oops! double post...sorry!

My thoughts exactly!

Eh... about 10 minutes. I don't think I'm gonna attempt a rejuv unless I'm 100% sure it's not going to give me anything at all. I'll try it on the tester again, though.

Nope! It's exactly what I thought it was: electromagnetic focus coil. It sez so in the Sams. It does have a trap magnet too...

I might do that!

Also, I pulled all the tubes and tested them, of the 19 tubes, 8 or so are bad in one way or another. I think I have replacements, I'll have to check.

Leave the tube on the tester for ~1 hour check back every 15 minutes. Wake up can be very slow.

The focus coil is adjustable so you can center the picture.

Agree about letting the CRT cook for an hour or more. You could try elevating the filament voltage to around 7 while it's cooking too.

Sorry the pics suck bc cell phone. There's a splotch of tar on the front plate - petrified tape residue from another era. An auction sticker on the side in photo #2 gives away a tidbit of this piece's history. Though the seller says he got it from a friend, and had it as a display piece until he moved to a smaller dump.

I took the chassis out and evicted most of the dust bunnies. Inside, it seems only to be missing a single tube shield thingy. Haven't catalogued which tubes I need yet, I only know that I need lots. It's kinda hard looking underneath the chassis with a 100-pound tube weighing it down, but all looks original under there.

Any tips for removing the crt safely?

I don't think there's any waking it up, btw. Let it cook for an hour, still tests around "1." The scale is kind of ambiguous, but 0 to 2 is "Bad," so...

Some testers good/bad indication is not always accurate. My B&K 466 will score some monochrome tubes middle of the bad scale when they still can produce a decent picture in a room with moderate lighting....Same tester will score color tubes that are dimmer in the low good range. It is always good to get to know your tester before using it to make decisions.

It may make a very decent picture with a brightener.

Tubes are usually not the main source of trouble in antique TV sets. What you should replace are all the wax paper capacitors and the electrolytic caps.

I've worked on a number of similar Admiral chassis. If the CRT is firmly attached, it's possible to leave it mounted and carefully tip the chassis on it's side to work on it. You may need to place a folder over towel or similar padding to help support and cushion the CRT

Here's where I'm at: I changed the 3 filter caps, and it powers on without throwing a hissy fit, taking only 50 out of the theoretical 200 watts. The main transformer buzzes a little bit still. I'm not getting HV. I replaced 6SN7 (AF amp/sync clipper) and 12AU7 (sync amp/sync sep), which were bad. The only other bad ones (still in there) are audio out, damper, RF amp, and 1st video IF. The 2 tubes in the HV cage are both good, and filaments light up.

I just want to see if I can get a beam out of the crt. I really don't want to recap the whole thing only to find I need a flyback or something. Not to mention the crt.

Ideas?

http://www.earlytelevision.org/pdf/A...Sams_100-1.pdf

You're very likely going yo have to do some recapping to get a raster. At least the horizontal oscillator and output circuit. Also this set uses a stacked B+ power supply design so the sound output tube needs to be biased correctly. Also make sure the speaker is pullged in as it's field coil doubles as a filter choke for the power supply.

I wouldn't worry about the flyback. I've never encountered a bad one. Also I[m local to you and have spare parts.

Did you have the speaker plugged in? It completes the B+ circuit!
It would seem that way, as the power consumption is only 50 watts.

Also if the damper tube is bad there is no way in hell you'll get HV out of it.

Expect to replace some lytics, the paper caps in the horizontal section and any paper caps on the B+ boost line that the flyback supplies before HV materializes.

lol I thought the speaker was wired strangely!

Thanks guys, I replaced the damper tube, and plugged in the speaker. Got a raster! It actually looks... not too bad given that it's all original (minus the filter caps). It lost it for a minute though, not really a big surprise, but it came back. I hadn't changed the damper tube because I thought I didn't have one! My dead-project RCA Victor tv DID have one though. Also the tube is surprisingly bright for testing 'bad.' Even in my brightly lit room, you could probably watch a show no problem.

brb recapping.

Cool! You're well on your way to having a fully working set :) Funny how a seemingly dead CT can produce a decent image.

I recapped about 80% of it, I ran out of caps I needed, and I still need one tube, a 6BC5. I put a test pattern signal into it, and it honestly looked like crap. Now I wait for parts to come in.

Hmm. I don't see a 6BC5 in the schematic. I'm thinking it's in the tuner but that shows a 6AG5. Perhaps is a production run change ? If it is in the tuner and is bad, for sure it would result in a crappy picture.

*scratches head* Dammit! And I already ordered a tube for it - the wrong tube, it is supposed to be a 6AG5. The vertical osc/amp tube was also wrong, a 12BH7 instead of 12AU7. According to my tube book, they're close approximations of each other, but meh. I'll just order another tube. I did put a 12AU7 in it, it didn't seem to make much difference.

Tube substitution manuals: For the repair man who's tube caddy ain't big enough for two similar types with different numbers... :D

If the other type seems to work well in the stage then it may as well stay, but if it don't going for the original number is the wise choice.

Truth be known, I store my tubes in tube caddies. Today,you can have a caddy for radio, another for audio, another for B/W sets etc. :D

That way, they ain't so heavy...

I sort of do the same thing....The stuff I've had the longest are in caddies sorted by number and tested. After that is is an unsorted mix of boxed NOS, and semi-sorted loose pulls (some stored in boxes after the caddys filled)...The pulls are sorted by type (HV diodes sweep power tubes, 7 pin, 9 pin octal/loctal signal, fat pin) A caddy FILLED with un-boxed loose pulls can get heavy fast. :D

A 6BC5 is the newer generation 6AG5. I seldom bought 6AG5's, always 6BC5's.
Way back then, I would try different variations of similar tubes, 12BH7 vs 12AU7 etc, to avoid having to troubleshoot the circuit.
That was in jobs where the set owner didn't want to spend too much money on an old set. :scratch2:

Many of us could probably cull our loose/unboxed tube collection by:

1. testing all the HV rectifiers 1B3-1X2-1V2-3A3 etc weeds out the open filaments at least. Id hate to stick a bad one in a working set.

2. testing all the damper tubes for gas-shorts again where fails are obvious on a simple tester

3. Testing 5U4's and sweep tubes in a working set. emission testers miss often the bad ones

4. Run a quick shorts-gas test on all the common triodes and pentodes 6CG7, 12AU7, 6SN7, 6CB6....

Ok, so. I recapped most of this set, but the picture didn't want to be right. So I ordered the rest of the caps, but then capacitorworld decided to screw up my order again, so I had to wait a while. I just got them today (from digikey) and put them in, but the picture is still crap. All the tubes test good, except the audio output (tested questionable), but the audio comes through clear (though with some buzz [a lot of buzz if the audio is silent]).

I've been fiddling with the adjustments. I noticed that the horizontal lock in range and horizontal drive trimmer caps were all the way screwed in, and the horizontal linearity coil thingy was very much screwed out. My main problem is with horizontal (although it looks like vertical has an issue too), as it seems the picture is overlapping itself several times horizontally. I'm a total noob at this, but judging by sound, it seems like the horizontal lock adjustment on the front speeds up or slows down the horizontal... um... 'drive'? But anyway, if I turn it up, the picture overlaps itself more, and down less. Unfortunately, it seems that the H lock in range is best set as far in as it can be. The H drive seems not to do much at all, but the picture is a bit clearer at just slightly less than all the way tight.

The other adjustments seem not to affect it much, which makes sense to me. The only thing I noticed while recapping is that one cap seems to have been replaced with a bumblebee. It was in a totally different place than in the Sams photo, and the leads of the snipped-out old one are still there. The stripes are discolored and I'm colorblind anyway, but my thingy measures it at .02 so I put a .022, but the diagram calls for .01. It's C32 for anyone with the Sams. It just goes to ground from a sort of... 'rail' that comes off of one side of the brightness pot, it goes to lots of things including a grid on the video amp and the audio output and all over the place. Actually now that I really look at it, it seems to have a lot to do with the horizontal stuff. Hmm.

The pic below is supposed to be an indian head test pattern.

Ideas?

Looks like the horizontal frequency is too low... there is a slug adjustment on the back of the chassis for horizontal frequency (it is protected by a metal bumper) turn that and observe the effect on the multiple overlapping images.

jr

Hi,
I finished up a recap on an Admiral 20X1 chassis a few weeks ago. I was having trouble with horizontal AFC , just like your picture shows. I found the issue in my case, was the horizontal stabilizer coils' adjustment. It is on the underside of the chassis. I had to back (turn) the slug all the way out, to the end of its' travel. This adjustment is on the opposite side of the horizontal frequency control slug.
Make sure you follow the set up procedure in the Sams for the horizontal oscillator adjustments.
I posted a picture with an arrow pointing to the slug adjustment.
Ed

Thanks guys. I had played with the H frequency before and it did nothing. I went back and unscrewed it nearly all the way, and the picture fell right into place. And I didn't even realize there was a thingy under the chassis. One little problem though...

I'll be following the Sam's instructions for an o-scope based alignment. But idk if that'll fix this. And before you go and mention the picture alignment device, it's already maxed out. Plus there's a clean straight end to the picture.

EDIT: apparently my input device is messed up. fml