Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Jul Tue 23, 2019 2:09 am


All times are UTC [ DST ]





Post New Topic Post Reply  [ 37 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Mon 08, 2019 5:50 pm 
New Member

Joined: Sep Thu 20, 2018 8:53 pm
Posts: 14
Hi all,

I picked up a 1956 Admiral C23B2 console set recently (20Y4E chassis). I'm able to get sound and static on the picture tube. It also has a Parallel Vu-Brite C401 CRT brightener attached, albeit the image is still quite dim even at full brightness. But any attempt at getting a picture (via VHF transformer) only shows up as scrambled static, no actual image. I have attempted tuning of the horizontal drive, vertical linearity etc. but nothing has had any impact.

One of the vacuum tubes that was bad is identified as "SYNC SEP" on the diagram. I have a replacement on the way. Could that be a contributing factor to the lack of proper image? I also do not currently have a tube tester or dedicated CRT tester.

Also the Horizontal Frequency adjuster looks like this (the copper rod)... I'm not actually sure how to adjust it? The maintenance manual suggests "rotate the horizontal adjustment slug clockwise until the picture loses sync." But it isn't a typical adjustment screw and I can't seem to rotate it (I can move the entire 'rod' like an antenna basically.

The picture tube itself is a Motorolla 21CBP4A and has a "Code Date" of 190593 - Does this suggest it was put in circa 1993?

Thank you for any tips and advice.


Attachments:
IMG_8028 (Custom).JPG
IMG_8028 (Custom).JPG [ 91.47 KiB | Viewed 1333 times ]
IMG_8026 (Custom).JPG
IMG_8026 (Custom).JPG [ 156.48 KiB | Viewed 1333 times ]
Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Mon 08, 2019 6:42 pm 
Member

Joined: May Thu 14, 2015 4:15 pm
Posts: 1583
Location: Dallas, TX
It is kind of a wonder you got as much as did.
If you read some of the other posts here you will learn, as many do, that on a set that old that the capacitors and some other parts should be replaced. When the set was 5 years old the problem would have probably be just a tube, but 50 years latter much more is faulty because of the passage of time. Running this set without replacing the electrolytic capacitors risks damaging expensive parts like the power transformer and the rectifier tube.
The horizontal adjustment looks to me as though someone monkeyed around with it and attached an extension of sorts, the original adjustment screw looks bent over to the side.
The brightener is not a good sign. The picture tube is probably weak, replacements are not easy to find now and will cost just about more that any other part with the possible exception of the power transformer.

_________________
Tim
It's not the Destination, It's the Journey.


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Tue 09, 2019 3:37 am 
Member
User avatar

Joined: Aug Thu 12, 2010 6:25 pm
Posts: 268
Location: Durham, NC
It looks like the ETF has a couple of replacement CRTs available: https://docs.google.com/spreadsheets/d/ ... It/pubhtml
You can email them to find out about cost, shipping etc.

_________________
Mark Nelson
A collector of TV signal boosters and UHF converters -- God help me!
tv-boxes.com


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Tue 09, 2019 8:46 am 
Member

Joined: May Sun 07, 2017 11:35 am
Posts: 571
Location: Belrose, NSW, Australia
Rotate that bent shaft in the direction that causes the lines to get further apart. Keep going and pic should lock in. It may not be stable though.
Don't fiddle with the Drive control unless you know what you are doing.

The tube will look brighter if you take out the safety glass and clean it and the tube face. From memory I think you can do that from the front.

Don't run it for too long. You really need to re-cap it first, you've been VERY lucky to get this far!

Nice project!

_________________
Wax, paper, bitumen, cotton, high voltages - what could possibly go wrong?


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Tue 09, 2019 3:41 pm 
New Member

Joined: Sep Thu 20, 2018 8:53 pm
Posts: 14
Thank you for all of the suggestions and info! @aj2x I appreciate the link and am happy to know there are at least a couple picture tubes still out there that I could acquire in time. I do agree recapping is the most important but also new territory for me - I do have the original service manual photo folder and diagrams (as well as ones found online) but it'll take me some studying to understand what I'm doing!

I plan to invest in a CRT tester/rejuvenator in the near future which I think is valuable for any old TV troubleshooting. I'm just learning a lot about this. I paid $50 for this set knowing it had at least sound working and seems to be in quite good condition cosmetically. They just seem really rare to come by so I do hope I will be able to get it up and running again.


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Tue 09, 2019 5:27 pm 
Member

Joined: May Thu 14, 2015 4:15 pm
Posts: 1583
Location: Dallas, TX
Don't jump to any conclusions about the CRT. It is not unknown to happen that someone added a brightener to correct a problem that is due to something else. Also it is true that the older CRT never were as bright as a CRT from the 1980's. In the 1940s and 50s people commonly watched TV in a dimly lighted room.
Many times the "rejuvenation" function on CRT testers don't help that much and in fact could make things worse.
If you get into vintage TV enough you will realize that a TV like this is not "rare", they are uncommon.
Here is a restoration article of a somewhat similar TV from the era of your TV.
Admiral TV of that time were fairly good quality, maybe not the best but certainly not the worst.
https://www.antiqueradio.org/PhilcoF4626MTelevision.htm

_________________
Tim
It's not the Destination, It's the Journey.


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Wed 10, 2019 8:43 am 
Member

Joined: May Sun 07, 2017 11:35 am
Posts: 571
Location: Belrose, NSW, Australia
You are right about the brightener, I used to see these things stuck on to cover up e.g. a low G2 voltage fault caused by a high value resistor or a leaky cap.
Unfortunately they can shorten a good tube's life if used for too long.

You don't really need a CRT tester! See this link:
viewtopic.php?f=3&t=331576&hilit=How+to+test+a+CRT

If you get any reading with this test you'll generally have a usable CRT.

Oh, as I recall, to get the front glass off, first pull the knobs off. You'll find a couple of spring-loaded metal strips. Stretch them out and tilt them so they fit thru the holes in the glass.
At least, that's how it worked in the Aussie-made Admirals of the period.

_________________
Wax, paper, bitumen, cotton, high voltages - what could possibly go wrong?


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Sat 13, 2019 8:26 pm 
New Member

Joined: Sep Thu 20, 2018 8:53 pm
Posts: 14
As a :( follow-up, as predicted by comments here whatever abilities it still had re: the circuitry seemed short-lived. I did power it on a couple more times briefly to assess what I could, but the CRT had gone out completely (with or without the brightener attached) followed by newfound electrical smells. I will still try the multimeter test on the picture tube at some point when I get a 1k resistor.

My next probably foolish question would be... does there exist anything like a "new" universal/compatible chassis (non-vacuum tube, already recapped or modern built) that I could retrofit to still power the original/NOS CRT and speaker? I'd love to get this going using era-authentic audiovisuals even if the circuitry that powers it is completely different. But I also definitely lack the arsenal and experience to attempt rebuild of the chassis myself, though I still hope to get into the hobby as time permits.


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Sun 14, 2019 2:43 pm 
Member

Joined: May Thu 14, 2015 4:15 pm
Posts: 1583
Location: Dallas, TX
MattPilz wrote:

My next probably foolish question would be... does there exist anything like a "new" universal/compatible chassis (non-vacuum tube, already recapped or modern built) that I could retrofit to still power the original/NOS CRT and speaker? .

In a word no.
Since the picture tubes (CRTs) is something that isn't made anymore and the chassis is made of components that can be usually found or replaced with new components no one produces a modern chassis that replaces
an original one. Putting a flat screen TV in a vintage cabinet has been done but it does not look correct.
Years ago there was a company that made reproduction Philco Predictas with more modern CRT and solid state chassis. I think they were color chassis at that. The sets were very pricey and the company couldn't get CRTs after a while so the company is gone now.
Also for the most part collecting and restoring the old chassis as well as the cabinet of radios, TVs, etc. is what this forum is about.
There is a lot of free help here if you want to get into it yourself and also we might be able to get you in touch with someone that can do the work for you.

_________________
Tim
It's not the Destination, It's the Journey.


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Mon 15, 2019 6:41 am 
Member

Joined: May Sun 07, 2017 11:35 am
Posts: 571
Location: Belrose, NSW, Australia
I am surprised it ran for as long as it did, even that it fired up at at all.

Your smells could be many things. Electronics runs on smoke, you let the magic smoke out and it stops. Very common with old components that have been in hibernation for many years.

I could take you through step by step how to get it running reliably and safely. It's well worth doing and rewarding. You CAN do it. There are many others on this site who can help.

But a non-authentic old TV is a worthless piece of junk.

_________________
Wax, paper, bitumen, cotton, high voltages - what could possibly go wrong?


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Tue 30, 2019 4:21 am 
New Member

Joined: Sep Thu 20, 2018 8:53 pm
Posts: 14
irob2345 wrote:
I could take you through step by step how to get it running reliably and safely. It's well worth doing and rewarding. You CAN do it. There are many others on this site who can help.

Thank you irob, I really appreciate it and would certainly take you up on the offer for any assistance! I seriously want to restore this to its original specs and have been researching and investigating quite a bit these past couple of weeks just to learn more about the topic. Even found an old "How-To-Do-It Encyclopedia" from 1962 in my collection that includes 100 pages about old TV repair that I have been sifting through just to better understand some of the terminology and components.

Before I proceed much further, however, I want to at least run these three questions by you (or others) to make certain these parts are still replaceable/fixable as I've discovered more problems since I last posted.

1.) Flyback Transformer - When examining the vacuum tubes, I took the plug off the one attached to the flyback transformer and the flyback plastic exterior shattered (see photo). I am still awaiting the full photofact specs for this specific chassis (have some bits downloaded through Radio Museum but not with a parts list) but one for the 20Y4D that I have lists a few part numbers (e.g., 79D65-3, FB420, HVO-54, X-129...) Is this something that I would probably be able to obtain (compatible version) by monitoring eBay or some other source?

2.) Horizontal Frequency Adjuster - This whole part highly confuses me. I will share some photos. I took off the 'Flexible Shaft' extender (and metal bracket) that I displayed in the original post to better understand the underlying mechanism, and it only made it all even more boggling. I guess this model by default had the metal rod adjustment in the back (I saw identical model on YouTube that had it and the front panel also notes this). The coil had one metal strand with its tip soldered to the flexible shaft base (shielded, although all the coating came right off in the process of my tinkering). There is a cylindrical 'carbon' type component that was somehow affixed to the shaft albeit seemingly broken. That piece comes right out and at the bottom of the inside of the coil is nothing except the back of the PCB. So I'm not understanding how this functions to any extent as it is or if this can be readily replaced with a new part.

3.) Stubborn Screws - I wanted to check out the contents inside this black box but the screws refuse to budge at all and have even become a bit stripped attempting with electric drills etc. Is there a trick to this - should I spray some WD-40 around them to possibly loosen?

Thank you again! I'm committing to using this TV as my main learning platform to better understand this process, even if it takes forever.


Attachments:
IMG_8309 (Custom) (2).JPG
IMG_8309 (Custom) (2).JPG [ 113.26 KiB | Viewed 827 times ]
Horiz Freq A.JPG
Horiz Freq A.JPG [ 128.36 KiB | Viewed 827 times ]
Horiz Freq - B.JPG
Horiz Freq - B.JPG [ 122.14 KiB | Viewed 827 times ]
Horiz Freq - C.JPG
Horiz Freq - C.JPG [ 129.49 KiB | Viewed 827 times ]
Horiz Freq - D.JPG
Horiz Freq - D.JPG [ 112.29 KiB | Viewed 827 times ]
IMG_8319 (Custom).JPG
IMG_8319 (Custom).JPG [ 122.69 KiB | Viewed 827 times ]
Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Tue 30, 2019 12:53 pm 
Member

Joined: Jan Sun 18, 2015 5:01 am
Posts: 1386
Location: Waxahachie Texas
That black box is a transformer. If you want to remove the top there will most likely some nuts underneath the chassis that will have to be removed first. Also there might be some nuts between the bottom of the transformer and the chassis that will have to be removed too. Why do you want to remove that transformer?

_________________
Crist


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Tue 30, 2019 5:40 pm 
Member

Joined: May Sun 07, 2017 11:35 am
Posts: 571
Location: Belrose, NSW, Australia
Do Not try to remove the screws on the "black box". There is no need to do so and you will probably break something that you won't be able to replace.

The flyback transformer that you broke the wire and insulation from can be repaired if you can find the end of the fine wire on the honeycomb winding. If you can, we can talk you through fixing it with some epoxy resin. DO NOT attempt to fix it with silicone sealer, it will end in disaster. Be very gentle with that fine wire. You will have to solder it to the black wire that goes to the 1B3 cap.

The adjuster (which is actually the original presenting problem) is supposed to work like this:

The grey core (it's called Ferrite) is supposed to be attached to the brass screw. What is supposed to happen is, when you turn the shaft, the ferrite piece winds in or out of the coil. As it winds into the coil it increases the inductance and that lowers the frequency of the horizontal oscillator. Wind it out and the frequency goes up. When it's correct, the picture locks into place.

You can probably use a thin piece of plastic sleeving inserted into the coil to hold the ferrite in place inside the coil. That might allow you to move it very carefully in or out of the coil until your picture locks. As you get closer, the lines will get broader.

But you will have to fix the broken flyback first.

A tip based on many years of experience - disturb as little as possible, measure, and think with your head, not with your hands. Otherwise you will find yourself having to fix lots of things that weren't previously broken.

_________________
Wax, paper, bitumen, cotton, high voltages - what could possibly go wrong?


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Tue 30, 2019 6:38 pm 
Member

Joined: May Thu 14, 2015 4:15 pm
Posts: 1583
Location: Dallas, TX
Yes. Find out about how the parts and a TV works before going much further. Some problems can be found by looking but many others have no visible signs. You are about to find that fixing an old TV is a lot more complicated than you thought.
The flyback damage will take a very gentle touch. The regular sized wire going to the tube cap needs to be supported by the coating (probably a wax) of the flyback, the fine wire around the winding of the flyback is far too delicate. The black plastic (or wax) will need to be replaced, this location is one of the most high voltage parts in the entire TV, extreme insulation is required. Normally I would suggest replacing the larger size wire while you are at this point, old plastic or rubber insulation can become stiff and brittle. However this wire has to have a high voltage rating and is expensive. The fine wire has a very thin coat of insulating varnish on it. You must be careful not to damage the coating on the rest of the winding. This coating however will need to be removed from the end of the fine wire for a short distance so the solder will join it to the larger wire.
The horizontal hold coil might be better replaced eventually.
Neither part will be very easy to fine a replacement for.

_________________
Tim
It's not the Destination, It's the Journey.


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Apr Tue 30, 2019 8:59 pm 
Member
User avatar

Joined: Mar Sun 01, 2009 10:27 pm
Posts: 4980
Location: Ann Arbor, MI
irob2345 wrote:
The flyback transformer that you broke the wire and insulation from can be repaired if you can find the end of the fine wire on the honeycomb winding. If you can, we can talk you through fixing it with some epoxy resin. DO NOT attempt to fix it with silicone sealer, it will end in disaster. Be very gentle with that fine wire. You will have to solder it to the black wire that goes to the 1B3 cap.

Standard silicone sealer emits a weak acid when it cures. This is not good for electronic circuits. I have heard references to "sensor safe silicone" and to "high voltage silicone" that can be used in cases like this. But I have no idea where to get either one. GE Silicone II does not emit acid, but I have never heard of anyone using it to fix a flyback. It seems to me that you would want glue that does not dry super hard.

irob2345 wrote:
The grey core (it's called Ferrite) is supposed to be attached to the brass screw. What is supposed to happen is, when you turn the shaft, the ferrite piece winds in or out of the coil. As it winds into the coil it increases the inductance and that lowers the frequency of the horizontal oscillator. Wind it out and the frequency goes up. When it's correct, the picture locks into place.

You might be able to reattach the core to the screw using J-B Weld. This is a thick epoxy that cures quite strong and hard. You would have to make some sort of jig to hold them in alignment while the J-B Weld hardens. You could rebuild the top of the coil form with a coil of paper and some epoxy glue.

_________________
Tom


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Wed 01, 2019 7:01 am 
New Member

Joined: Sep Thu 20, 2018 8:53 pm
Posts: 14
Thank you for all of this valuable information. Some follow-up about the flyback:

1.) I have found the end strand and it is readily accessible (as circled in first photo).

2.) The break is clean and generally fits back in place, see additional photographs. There is the main broken piece with wire and then a tiny fragment that also fits back. Maybe this will make things easier to repair versus if the coating was crumbled and in many pieces?

3.) I notice there is a gap at the top of the coil, which may have always been there.

4.) The reason I initially was looking in this area at all was because the connected tube did not seem to be emitting any light or sign of life, so I was not sure it was making good contact or was a functional tube.

5.) Before any of this happened but after the picture tube stopped lighting up (audio was fine), when I mentioned smell of electric in earlier post, I noticed the outside vacuum tube (horizontal output) that also connects to the flyback was getting extremely hot and may have been the origin of this smell (impossible to touch without getting burned and even looked charred). Should any vacuum tube be getting that hot?

Thanks again, attached are some photos.


Attachments:
flyback - A.jpg
flyback - A.jpg [ 187.95 KiB | Viewed 728 times ]
Flyback - B.jpg
Flyback - B.jpg [ 179.42 KiB | Viewed 728 times ]
Flyback - C.jpg
Flyback - C.jpg [ 182.49 KiB | Viewed 728 times ]
Flyback - D.jpg
Flyback - D.jpg [ 136.49 KiB | Viewed 728 times ]
Flyback - E.jpg
Flyback - E.jpg [ 183.81 KiB | Viewed 728 times ]
Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Wed 01, 2019 8:24 pm 
Member

Joined: May Sun 07, 2017 11:35 am
Posts: 571
Location: Belrose, NSW, Australia
I think you can repair this as described by others. Solder the wire on then glue the broken bits back into place with epoxy glue. No sharp edges - the high voltage will cause corona and break things down quickly. Keep it clean and smooth. There's nearly 20,000 volts there when the TV is running.

The 1B3 filament will not light if the horizontal output stage (that very hot tube) is not working (the 1B3 gets its voltage from the flyback), which could be caused by the horizontal oscillator not working, which in turn is likely to be a broken horizontal hold adjustment coil. The reason that tube gets hot is it's not being driven by the horizontal oscillator and so will turn hard on. Don't leave it running like that, you will destroy the tube and other parts.

It would pay you do do some reading on how TVs work. If you can find a copy of "Basic Television" by Bernard Grob (try Ebay) it is period correct and explains things simply. Highly recommended.

That TV has historical significance in that it was the first to use printed circuit boards AFAIK.

_________________
Wax, paper, bitumen, cotton, high voltages - what could possibly go wrong?


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Fri 03, 2019 2:47 am 
New Member

Joined: Sep Thu 20, 2018 8:53 pm
Posts: 14
Thank you for the book recommendation! I just ordered the 1952 edition which seems like it'd be the closest match to the earliest sets like this. The next edition is from 1975 I wasn't sure if that'd be quite as relevant for 1940s-50s sets. It will probably be summertime when I have more availability to work at this, but will study up as much as I can in the meantime.

About the flyback, is it a problem with its operation and the voltage if there's still an open gap, even if I reattach the broken part I have? I also looked on the underside of the part that broke (where the thick wire/cap is attached) and there is no wire end inside, but some type of tape/adhesive instead. Is it possible this flyback had already been repaired one other point and/or is the tape a conductive material that wouldn't require me to solder anything to the thin wire on coil?


Attachments:
IMG_8352 (Custom).JPG
IMG_8352 (Custom).JPG [ 88.17 KiB | Viewed 657 times ]
IMG_8359 (Custom).JPG
IMG_8359 (Custom).JPG [ 66.24 KiB | Viewed 657 times ]
Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Fri 03, 2019 2:56 am 
Member
User avatar

Joined: Mar Sun 01, 2009 10:27 pm
Posts: 4980
Location: Ann Arbor, MI
The tape would have prevented the solder joint from resting directly on the winding and digging into it. And if it was originally sticky on both sides, it might of held the thick wire in place while the plastic was being applied. The fine wire probably broke flush with the end of the tape and would be hard to see. You could use some of whatever glue you use to cover the winding in the gap.

_________________
Tom


Top
 Profile  
 
 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Fri 03, 2019 7:59 am 
Member

Joined: May Sun 07, 2017 11:35 am
Posts: 571
Location: Belrose, NSW, Australia
I concur with Tom. Use some similar tape when repairing the damage. You will have to solder the wire. Usually a hot iron and some flux will strip the insulation on the wire for you.

'52 Grob will suit you just fine, it even has some parts of Admiral circuits in it as examples.

The Admiral was a pretty basic circuit and followed then-common US TV design practice closely so the examples in the book will be close to what you have.

We saw a similar model to your TV in Australia for a year or so after TV started in 1956. Admirals were locally made by a large appliance manufacturer and sold well, being the first 21 inch TVs when all the other brands had launched with 17" sets. I remember that chassis although it's been nearly 50 years since I worked on one.

While I think of it, your CRT may be quite OK. A common fault with early Admirals was a resistor that went high in the CRT's G2 circuit, reducing the brightness. Badly trained techs (that's being polite) would "fix" it by adding a brightener, as is fitted to yours. That would shorten the CRT's life.

_________________
Wax, paper, bitumen, cotton, high voltages - what could possibly go wrong?


Top
 Profile  
 
Post New Topic Post Reply  [ 37 posts ]  Moderators: 7jp4-guy, Mr. Detrola Go to page 1, 2  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 5 guests



Search for:
Jump to:  


























Privacy Policy :: Powered by phpBB