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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Fri 03, 2019 7:22 pm 
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Location: Dallas, TX
On the flyback construction I've see of this vintage there would be a solid wire loop with "legs".
The cloth tape is put down on the windings, then the solid wire loop is glued down. The fine wire of the winding is soldered to the loop, then the larger wire is soldered to the loop. The loop serves as an anchor.The coil is dipped into melted wax as it is rotated, this puts a wax insulating "tire" on the coil. The coil is then assembled on the ferrite core. Your flyback could use black wax or it could be plastic. The wax can be melted and re-used. If the covering can be melted then the solid wire loop ( and cloth tape) can be recovered and used again.
There is no way to solder the wires afterward if you tried to glue the large piece that broke off back first. You will have to solder the wires then fill in the space where it broke off.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Fri 03, 2019 9:25 pm 
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You might need to extend the broken fine wire to have enough length to reach where the heavy wire is. One source of fine wire is one strand of the type of stranded wire used in lamp cords. Most hardware stores sell that by the foot. Taking apart one of your lamps would leave you in the dark! :) If you do extend the fine wire, put down a longer piece of tape to protect the winding from both solder connections.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Sun 05, 2019 11:39 am 
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@Notimetolooz, you are 100% correct in your description of this flyback piece! The large wire with cap has two solid wire loop 'legs' that were pressed flat between the coating and the tape material, with the thin wire (from coil) running through the middle and presumably soldered underneath the wire insulation to the large wire going to cap. There is at least 3/8" of the thin wire still protruding from this piece, which would be where it broke off from the thin piece still on the coil.

I can confirm that the coil coating of this flyback is a hard plastic. I tried burning one of the small fragments that had broken off and it burned up and disintegrated into a strong plastic odor. I understand that might be uncommon as most I've read about use some form of wax. The original coating that is still affixed to the coil seems solid yet, but to get at the large wire for eventual repair the larger broken piece I've shown in past pictures broke apart in unfixable ways (too many small/sharp pieces to try and fit back together with adhesive).

I think the thin piece I found still attached to the large wire may make this easier, possibly with just one solder point from that to the existing piece on coil rather than having to extend anything. I'll have to find a new material to recoat this broken area. Someone on YouTube used Permatex Ultra Grey (sensor-safe, low odor, non-corrosive) Gasket Maker adhesive to seemingly repair one similarly - such as https://www.amazon.com/dp/B004WJPMHQ. Does this seem feasible? Also for tape to protect the solder point would electrical tape be rated good enough for the job?


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Sun 05, 2019 2:39 pm 
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Location: Dallas, TX
It is possible that that flyback is a replacement manufactured sometime after the TV was made, but either way
you will have to replace the missing chunk of plastic. I'm not sure which silicone rubber is the best to use. it
is true some general purpose silicone rubbers emit acid fumes. I'm not sure how well the silicone would bond to plastic tape, I think that is why they chose cloth.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Sun 05, 2019 7:08 pm 
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Location: Belrose, NSW, Australia
For the tape, try medical Micropore or similar. You can use several layers and you'll find it easier to work with than vinyl insulation tape.

If you can accept that you will never be able to access the connection again once it is sealed, epoxy resin is the best solution. Philips used epoxy to seal all their HV overwinds since the early 60s. Can't say I've never known one of these to fail but there were always other reasons for those failures, like mis-adjusted HV controls.

Try to find a plastic cup with a base of the same diameter as the winding, with a bit to spare. Trim the cup down to 20mm (about 3/4 inch), cut the necessary holes, insert the winding, mix the 2 part epoxy and just pour it in.

Do check with an ohmmeter that it's connected first!

This will be a PERMANENT fix!

When the epoxy sets and assuming your cup is made of LDPE, the cup should come away from the epoxy. If it doesn't, don't force it, leave it there.

Oh - when you dis-assemble the transformer core, don't lose those thin paper pieces between the core faces. They might not look much but they need to be there and they have a very important role to play.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Tue 07, 2019 2:17 pm 
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Thanks as always for the added information and suggestions. Follow-up on my own progress and discoveries:

1. I finally gave @irob2345's CRT testing trick a whirl... The CRT definitely seems drastically diminished based on those findings. It topped out at 0.721 Volts and that was after minutes of build-up, using a brand new 6V battery and 1K resistor. Perhaps it can still be used at least during the chassis restoration efforts? As I noted in my very first post when it was still at least powering up, the screen was very dim even with the brightener and max brightness. It was still visible in subdued lighting, though.

2. I believe I managed to find two NOS flybacks that I ordered as backup. I haven't received them yet but here are photos; the one on the left even uses the same looking coating. It was a very obscure reference I found after much research, since this alternate model is not noted in the PhotoFact or practically anywhere else. I found a single reference to it being a replacement in the March 1958 "Radio-Electronics" catalog, under NEW DEVICES: "FLY-126 replaces Admiral 79D65-1, 2 - Thordarson-Meissner Mfg. Co." The 1965 Thordarson catalog instead lists FLY-136 as the replacement, a model that didn't seem to exist previously. In all of the official Thordarson catalogs I find, FLY-126 is listed as a Silvertone replacement while FLY-136, when listed, is for Admiral, so hopefully Radio-Electronics didn't make an error in noting this.

3. I also ordered a listed compatible Vertical Output Transformer, simply to have on hand in case the one currently in use is ever determined to be bad since compatible parts again seem obscure to come across.

I'll be traveling quite a bit and it'll likely be June-July when I will have more availability but am still learning more each day. Also have my eyes open for a good oscciliscope as I suspect that'll be a valuable tool in troubleshooting down the road.

EDIT - I did just notice that the box for the flybacks indicates "70 degrees" while the 21ALP4 CRT specs note an 85 degree horizontal deflection angle (68 vertical, 90 diagonal). Might that be a problem?

EDIT 2 - To illustrate how poor the CRT is responding, to go from 0.3V to 0.4V took 35 seconds, 0.4V to 0.5V took 53 seconds and 0.5V to 0.6V took 1 minute 53 seconds.


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: May Tue 07, 2019 9:37 pm 
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Location: Belrose, NSW, Australia
Either of those flybacks will work, the Admiral uses a very common arrangement here.

With those numbers your CRT might be a little dim from cold but will brighten up over 5 or 10 minutes and should be quite OK. Not as good as new but quite watchable just the same.

As you turn the brightness control up, there should be spare adjustment at full on where the picture washes out. If this is not the case, you have a fault in either the G2 circuit or the brightness control circuit itself, could be a resistor gone high or a leaky paper cap.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Jun Mon 17, 2019 6:59 am 
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It's been a hectic last month for me but little by little I have continued researching into this restore project. Here are the latest updates, questions and so forth...

What I Have Acquired
  • Basic Television Principles & Servicing (2nd Edition; 1954) by Bernard Grob - I have not managed to read more than the introductory chapter or so, yet.
  • Television Simplified (6th Edition; 1962) by Milton S. Kiver - Not yet received.
  • Stancor A-8141 Vertical Output Transformer NOS, directly interchangeable with Admiral original. (Don't know how often these go bad but it is hard to find listed replacements so I got it as a spare in case).
  • Thordarson FLY 126 Horizontal Output Transformer NOS (x2), reportedly interchangeable with Admiral original. (One has some very minor broken coating, have not assessed the other yet.)
  • Original SAMs PhotoFact guide for the 20Y4E chassis, and another of the somewhat different 20Y4D by mistake. (I then scanned in the correct guide at very high resolution and produced searchable PDF for easy personal reference.)
  • 21ATP4 CRT Picture Tube NOS from ETF. (Not yet received. I did so preemptively to ensure that if I do manage to get the rest of this TV functional again I will have a spare tube, knowing that my current one is quite weak and has used a brightener).

What I Have Done

Not a lot, but did read the guide here on recapping a couple of times. I also familiarized myself with the process of removing the chassis. I carefully disconnected and removed the chassis for inspection. I collected each group of screws/components into individual labeled bags so I know where everything is during reassembly. The "back" side of the chassis that faces the front of the TV where most of the wires are is extremely dirty and greasy, vastly worse than the side with the tubes and connectors. Also being new to this hobby it seems quite overwhelming! A couple screenshot are included.

Where Should I Start?

Is there anything that I can do to ease into repairing this as I gradually learn more? Where should I begin, without yet having an oscilloscope or other testing hardware beyond a multimeter? I first checked into resistor replacement as that is cheap and a single resistor kit on Amazon has most of what I would need, is that a common recommendation to replace them all? Capacitors being the obvious next one, at least the paper ones. The canned capacitors (with 3-4 values listed each) is where I will need more guidance as that part seems very foreign to me on how to remove and replace.

What about wiring, do you often run new wiring or just resolder the existing ones as needed to the new components? If new, what gauge/type of wire is recommended?

Flyback Confusion

The replacement flybacks did come with a wire schematic that I can post in the future, but I think that entire process will be another conversation in itself especially the current vs. new wire/pin configurations. The PhotoFact does not include that specific replacement model (FLY-126) since I think it came out later, but suggests that Thordarson connections use 5-4-2-1 in place of 5-6-7-8 for terminal connections and "requires 2 turns for filament winding." The current flyback has the two wires connected to pin 2-4, then a red wire from pin 7 that has some other end just hanging that I don't yet comprehend. See photo. There is a resistor connecting pins 4 to 7.

Thank you for your time!


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Jun Mon 17, 2019 3:12 pm 
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Somebody else will probably tell you more information here, but I have heard that it is best to start out with a simple "All American Five" (a cheap and common 5-tube radio) to work on. You can try your recapping skills on it, and when you feel confident that you can work on the tv, you can move on to that. Check craigslist or eBay for inexpensive AA5 radios. Ones from about 1940-1947 or so are usually easy to work on. Good Luck!

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Jun Mon 17, 2019 4:28 pm 
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Resistors usually don't cause harm when they fail and they can be out of tolerance and the set will often still work, just not as good as it should... Resistors are rated for resistance (and tolerance: how close are to the labeled value they are supposed to measure) as well as wattage....If you replace a 2W resistor with a 1W the new part will burn up, but the other way around is fine... Think of it like replacing a load bearing 2x4 on your deck...If you don't have a 2x4 don't use a smaller board. Honestly unless a set has problems after cap replacement I don't bother with resistors. If a stage is performing badly replacing resistors that test outside of tolerance is a good move and if a stage has an intermittent problem changing all resistors in that stage may efficiently solve it but other than those cases your just throwing away time.

If you have never soldered before the paper caps not on the boards will be most straight forward. The caps on the boards will be next simplest but you must be gentle and careful not to damage the delicate early PCB traces. Lytics are polarized... connect them backwards and the replacements will explode, become ruined, and possibly take other parts out. Single section lytics are straight forward. Multi-section lytics come in 2 types: metal can and cardboard tube. The tubes color code the leads and have a label explaining it. One thing to know is that nearly all multi section cap is just a cluster of single caps with all the negatives connected together and tied to the can or brought out on a wire. Cans have 3 or 4 terminals on an outer ring connected to the metal can and 1 to 4 terminals on an inner concentric ring connected to the individual positive terminals... the positive terminals are marked with square, semi-circle, triangle and blank to distinguish the different sections usually in the insulator phenolic around the terminals...the can will have a label with those identifier markings explaining what capacitance and voltage is associated with each.... that data should also exist in the photofact on the schematic and parts list.


Tom Schulz wrote:
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..

I'm guessing you don't go to auto parts stores.... That is where to buy it.


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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Jun Tue 18, 2019 2:08 am 
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OK, Matt, you enthusiasm is fine but don't shoot your whole wad at once.
Ha! Leave some of those parts on the shelves for others to use.
First, you can use a soft brush and a vacuum cleaner, carefully, to get rid of some of the dust. Watch out for paper labels and such that may be loose and wouldn't want to get sucked up. Another technique that I sometimes use (outside) is air from a small compressor with the pressure regulated down to a safe level. You don't want to blow a hole in the speaker or do similar damage. Some areas can be cleaned with alcohol on a paper towel or similar (stay away from ink stamped info, alcohol will remove ink). I've also have used cleaners like Simple Green. Keep in mind that plastics and cardboard and the like get very brittle with age.

I second the idea of restoring some radios first. There are some good vintage radio restoration books available, the same process applies to TVs (fewer people restore vintage TVs so no books).

I don't know if you checked out the rest of Phil's website, but here is a page showing most of the radios and TV that he has restored. It kind of shows that these things are not extremely rare. He is a member here.
https://www.antiqueradio.org/restoration.htm
Also you can look through all the postings here and get an idea of the sets that others are working on.
After clean up start with replacing the electrolytic and paper caps. Leave the resistors unless they are burnt or you are removing them anyway to get to something else. I will ad that some resistors as in the tuner should be carbon composition, not the common film resistors. Film resistors are made with the film cut in a spiral which may cause them to work like inductors in VHF circuits. You should not replace things in the tuner anyway, cleaning the contact is OK.
The info that came with the replacement flybacks would be the best guide to the proper hook up.
After the caps, the tubes, cleaning switches/sockets and whatever you do with the flyback, then see how the set works.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Jun Tue 18, 2019 2:34 am 
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Here is an example of one of the vintage radio restoration books available. I did find some typos in the earlier edition I have. It isn't expensive and is a good starting point.
https://www.amazon.com/Old-Time-Radios- ... 8&me=&qid=
I was at a HAM convention a couple of weeks ago and one of the vendors had some old books. I looked though a 1948 edition of the Kiver book, it looked good, a little too early for the sets I work on. I wouldn't mind having the 1962 edition.

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 Post subject: Re: 1956 Admiral Console - Some general technical questions
PostPosted: Jun Tue 18, 2019 8:43 pm 
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Location: New Hampshire
IMHO do NOT do a recap yet. & TAKE YOUR TIME !
First fix or get a new horz hold coil. At that point you will probably need to get a new horz out tube.
It probably was damaged by no drive from the horz osc. Next fix or replace the flyback.
Now you should be back where you were & also be able to sync in the pix !
Do your recap one stage at a time & a few caps at a time RECHECKING the TV as you go !
Start with any stage that is not working right. If the set seems to run pretty good start with the
electrolytics.
BTW most Admirals were very good sets till the 60's when they went down hill. When solid state
sets came out they started building high quality sets again for a few yrs but soon closed shop.
When done this should work quite nicely.

73 Zeno 8)
LFOD !


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