Working on First GE Color - Page 2 - Videokarma.org TV - Video

NewVista · #16 03-21-2011, 12:05 AM

Quote:

Originally Posted by old_coot88

..it doesn't use a 3.58 reference oscillator at all, right?

Yes, in the Wallace Manual you see a Burst-Gate, then a Hi-Q Crystal Tank Circuit, then buffer/clipper-limiter to deliver subcarrier phase-locked to Burst. I knew GE did this in the sixties but, as others have pointed out, Motorola and Admiral also sometimes used this ingenius idea.

old_coot88 · #17 03-21-2011, 07:13 AM

Quote:

Originally Posted by NewVista

Yes, in the Wallace Manual you see a Burst-Gate, then a Hi-Q Crystal Tank Circuit, then buffer/clipper-limiter to deliver subcarrier phase-locked to Burst. I knew GE did this in the sixties but, as others have pointed out, Motorola and Admiral also sometimes used this ingenius idea.

Interesting. On a related note, in 1969 we pulled a (then) late model GE into the shop with a really bad color sync problem that couldn't be fixed in the home with tubes. Noticed an NE-2 neon bulb in the burst area of the circuit board and tried replacing that, and it fixed the problem. I don't remember the details of the circuitry as GE was not one of our store's specialty brands. But the NE-2 was involved in the burst gate circuit.
Bill(oc)

Electronic M · #18 03-21-2011, 01:05 PM

If I were in your shoes I'd try making a mounting for the 21" tube. I always thought that large mask arround th CRT was GE's way of saying " this was supposed to be a 21" set , but those slow pokes at RCA never supplied us with one ". I got to start scowering milwaukee closer, that is the second 54' color set in my area that I've missed! Finding one in the wild is the only way that I might be able to afford one in the next few years, and I'd really like to own a first year set.

Good luck on your restoration!

Tom C.

Bill R · #19 03-21-2011, 04:55 PM

If you install a 21 inch crt in the set, and the picture only fills the center part of the screen like in the photo. Would you even need much dynamic convergence. That would be interesting to try to retrofit a 21 inch crt. Especially if it can be undone in the event of a breakthrough on rebuilding the 15Gs.

NewVista · #20 03-21-2011, 10:24 PM

Quote:

Originally Posted by Bill R

That would be interesting to try to retrofit a 21 inch crt. Especially if it can be undone in the event of a breakthrough on rebuilding the 15Gs.

I thought it would be a good idea last night noting the detatchable 15GP mounting sub-board -- and then retaining the 15GP masking (as yoke underscans on a 21" to approx 15GP picture size). Cabinet Width is fine, but then discovered there is simply not enough height for a 21 (as big as the cabinet is)

andy · #21 03-22-2011, 12:40 AM

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JB5pro · #22 03-22-2011, 04:29 PM

Does anybody know how many would pay a decent price for a rebuilt 15GP22? I wonder if the demand for them will ever be enough to produce any. It seems like there are enough sets in need to make it worthwhile.

NewVista · #23 03-22-2011, 05:15 PM

Quote:

Originally Posted by andy

What about one of those Japanese 19" large neck rectangular CRTs?

If they have approx 2"dia neck that would be Dandy. Will keep an eye out

Phil Nelson · #24 03-22-2011, 06:27 PM

Quote:

Originally Posted by JB5pro

Does anybody know how many would pay a decent price for a rebuilt 15GP22? I wonder if the demand for them will ever be enough to produce any. It seems like there are enough sets in need to make it worthwhile.

If you mean rebuilding old 15GP22 tubes, smart guys have been working on that for years without a perfect, affordable solution. Search this forum and you should find many discussions.

If you mean building new 15GP22s from scratch, the R & D expense would be insane. If this was possible at reasonable cost, it would have been done years ago.

Just my $0.02.

Phil Nelson

Steve McVoy · #25 03-22-2011, 08:12 PM

We are confident that RACS can rebuild them. The one they did a year ago is still going strong. I expect that within the next couple of months they will give us a price for the rebuild, which I expect will be over $1000. Even with shipping to and from France, I think this will still be a price that collectors will be willing to pay.

vintagecollect · #26 03-26-2011, 12:32 PM

The museum efforts at a rebuild are noble. Hopefully they will be successful soon. The rebuild price is expected, shipping it half way around the world has risks. What is the costs of shipping. A proper crate and packaging easily doubles the size of most things shipped international for protection. Can this double the rebuild costs?

Those folks at RACS do mighty fine work. Museum rebuilding would allow for in person drop off and pickup- for faster turn around while avoiding hazards of long distance shipping. I have not shipped anything overseas for a long time, oil prices makes this even worse now.

JB5pro · #27 03-27-2011, 12:02 AM

Quote:

Originally Posted by Steve McVoy

We are confident that RACS can rebuild them. The one they did a year ago is still going strong. I expect that within the next couple of months they will give us a price for the rebuild, which I expect will be over $1000. Even with shipping to and from France, I think this will still be a price that collectors will be willing to pay.

That is great! I knew you guys could do it! I would build a wooden crate for such a tube that could be dropped from 10 feet high on any side or top without harming it to be sure it could arrive safe. May be a bit costly but worth it and the container could be sold to each other person that needs a 15GP
I am so very impressed with all of you involved to hear the rebuilt tube is strong after a year. I think that is incredible!

JB5pro · #28 03-27-2011, 12:05 AM

the economy will be great in a couple years and mint '54 RCA and all others that use the 15gp22 will go up to $15,000.00 .

dieseljeep · #29 03-27-2011, 06:44 PM

Quote:

Originally Posted by andy

What about one of those Japanese 19" large neck rectangular CRTs?

I think those big neck rectangular tubes were 16 inch. 16CYP22 There must have been a lot more of those made than the 15 inch roundies. I heard that Conrac monitors used them as well as the Sears and Toshiba.

NewVista · #30 03-29-2011, 08:25 AM

Quote:

Originally Posted by dieseljeep

I think those big neck rectangular tubes were 16 inch. 16CYP22 There must have been a lot more of those made than the 15 inch roundies. I heard that Conrac monitors used them as well as the Sears and Toshiba.

Cool, would like to find one, will be now tuned in to old portables at garage sales!