View Full Version : URGENT-Get Your CRT Tubes Rebuilt Soon!
vintagecollect 02-03-2009, 12:45 PM Scotty at Hawkeye is knowlegable, friendly and great on helping us rebuild old CRTs, there's no question about that. In a recent phone call, he's stated that business is slow and not sure how long will stay open. I urge all AKers considering a CRT rebuild to do it soon.
I missed the chance to use a local CRT rebuild shop 8 years ago which was of couse the last in my area to survive.
Everyone should work on getting their rebuild projects planned before this business is gone forever.
newhallone 02-03-2009, 01:25 PM What does shipping usually run? I know it depends where you live........
zenithfan1 02-03-2009, 01:56 PM I plan to have two 21FBP22s rebuilt this summer. He isn't closing up that soon is he? I was going to drive out there, I don't trust shipping them.
newhallone 02-03-2009, 03:39 PM perhaps a group run could be an idea....
bgadow 02-03-2009, 03:51 PM I have a couple duds that I'd love to have done but I can't justify the price with shipping. Maybe something could be arranged whereby everyone would take their tubes to the ETF convention and then someone else could drive a truckload out to Hawkeye? Just an idea.
julianburke 02-03-2009, 05:34 PM Yes, I'm sure business is slow for him as how much is it that he wants to build a 21FB??
I stilll haven't heard any prices. What about a group effort?
El Predicta 02-03-2009, 06:26 PM Greyhound's the way to go on this. I shipped a 21" Predicta dud to them last week from here in Mesquite, Tx. (DFW suburb). With insurance, it was $40 and there the next day. Greyhound doesn't use machines and therefore it's safer. A real side benefit with that is that you don't have to pack like you do for the others. Also quicker and less expensive.
Larry W.
KentTeffeteller 02-03-2009, 07:34 PM I second Greyhound for shipping CRT tubes to Hawkeye. As long as well packed, they arrived without any issues or damage. AKers, get Hawkeye busy rebuilding tired Roundie tubes and ye monochrome CRT tubes. Let's see the end of analog TV and the beginning of digital in style!:tresbon:
colorfixer 02-04-2009, 11:06 PM I'm sure that if everyone gets off their ass, and starts to send in tubes we've all been procrastinating about and putting off getting done, there will be lots of work for Scotty.
Like any small business, with cash flow, its easier to stay around.
AUdubon5425 02-05-2009, 01:08 AM I'm going to call him about my 23MP4 when my tax refund arrives.
Has anyone written up directions for the proper way to pack a CRT for shipping?
compucat 02-05-2009, 11:09 AM I paid around $400 including shipping to have my 21FJP22 rebuilt by Hawkeye. I can definitely say it was worth every penny. He did a fabulous job.
bgadow 02-05-2009, 11:32 AM I'm going to call him about my 23MP4 when my tax refund arrives.
Has anyone written up directions for the proper way to pack a CRT for shipping?
There were some good ones on here, including diagrams. But they are buried deep and I don't remember what the thread was called. The basics are: pack it face down, with some padding at the bottom of the box; around the neck you use an egg-crate design with interlocking cardboard pieces which gives good protection if properly designed. If you look at most old picture tube boxes, that is how they did it.
electroking 02-05-2009, 01:02 PM I understand Hawkeye will send you a proper (empty) box for shipping your
tube on request (I believe I saw this on their website). Good luck.
vintagecollect 02-05-2009, 06:32 PM Anyone can pack a CRT with some info, I'll do some pics of a CRT box a company did for a tube of mine 2 years ago
rcaman 02-06-2009, 11:00 AM 5 or 6 years ago i called scotty about the 21fjp,s he said he had only 4 or 5 guns left and there would not be any more. i bought a gun assy for $125.00 now he seems to have plenty he is a damn lier. i would not trust him as far as i could throw him. steve
Steve McVoy 02-06-2009, 12:48 PM I don't know why you assume that Scotty lied to you. At that time he probably only had a few left, but they have been surfacing from various places since then. I've never had anything but honesty from Scotty.
Dan Starnes 02-06-2009, 08:20 PM I need to get my Predicta Holiday CRT to him, good idea on the tax return, that is what I will do with mine.
Dan
John Folsom 02-06-2009, 09:35 PM Steve McVoy is correct. I have dealt with Scotty in person, visited his business, and watched rebuild tubes. Scotty is EXTREMELY honest. Four or five years ago, when I first became involved with Scotty, he indicated that his supply of 21" round CRT guns was very limited. But he has since found a source of supply of new-old-stock guns, and now there is an ample supply. So this exonerates Scotty. He was not, and is not a liar. Shame on you for calling him one.
ohohyodafarted 02-06-2009, 10:35 PM Same what John Folsom said!
bluenorm 02-07-2009, 11:07 AM Long live Scotty and his business
NowhereMan 1966 02-07-2009, 11:26 AM Long live Scotty and his business
Mega-Dittoes to that one!
rcaman 02-10-2009, 03:00 PM so you are calling me a lier. he said there would be no more period. he lied he f$$king lied. steve
zenithfan1 02-10-2009, 03:42 PM Steve McVoy is correct. I have dealt with Scotty in person, visited his business, and watched rebuild tubes. Scotty is EXTREMELY honest. Four or five years ago, when I first became involved with Scotty, he indicated that his supply of 21" round CRT guns was very limited. But he has since found a source of supply of new-old-stock guns, and now there is an ample supply. So this exonerates Scotty. He was not, and is not a liar. Shame on you for calling him one.
Steve, did you read this? Maybe at the time when you talked to him, he thought there were going to be no more guns. He later found a source for them. Now there are guns. That does not make him a liar.
Steve McVoy 02-10-2009, 04:00 PM Steve, no one is calling you a liar. I think the explanation you got from me and from John Folsom explains why Scotty told you there were no more guns.
Steve McVoy 02-10-2009, 04:29 PM A collector sent me this:
I just was in communication with VDC about a couple of round CRTs for my early color sets, and received the following good news from them. They still rebuild some of the old color units at $250 each.
Also I have been in contact with Jeff Aulik from Clinton in Illinois. I specifically asked him about rebuilding the Philco Predicta CRTs because he told me a year before that they still do those. Here is his recent response: "We do and we don't rebuild CRT's at Clinton. Rebuilding is extremely time consuming. Everything is done by hand by the Engineering staff, from making the electron gun to putting the finished tube in a shipping box. We accept only a small number of rebuilds each year, chosen on the basis of which ones can make us enough profit to justify the number of hours spent, in addition to the oddball and sometimes expensive items that have to be scrounged up (usually related to making the electron gun.)"
So, there may be options for having your tube rebuilt. Check with Video Display and Clinton.
Erv Kuczogi
Video Display Corporation
570-253-3910
Jeff Aulik
Clinton Electronics
(815) 633-1444
Eric H 02-10-2009, 04:30 PM Does anyone know if Scotty can rebuild the 7DP4 for the 621TS?
The electrostatic focus makes it an oddball.
John Folsom 02-10-2009, 05:03 PM I had Scotty rebuild a 7DP4 quite a few years ago. If he still has (or can get) guns, he cn rebuild them.
radotvguy 02-11-2009, 06:46 AM I never had anything rebuilt by Scotty however i spoke with him many times over the phone and he seems very pleasant . At one time i was going to have a round color tube rebuilt by him and that was a few years back . At that time he did say his supply on the gun assembly for that tube was limited however he stated he was searching for more becuase of the demand and rarity of that gun . He was nice enough to stear a guy to me who needed a few b/w tubes being i had a lot of crts at that time and i made a few bucks as well . Enough to buy something else to putz with . Cant say anything bad about Scotty , he always seemed nice and pleasant . Even the famous Vaughn in Long Island always spoke well of Scotty and they do buissness often i think .
RCAkid 02-11-2009, 01:13 PM While I haven't had Scotty rebuild a tube for me, I too have been in touch with him and found him to be quite straight up. He had warned me about the shortage of guns as well and that he was trying find a source but at that time whatever he had is what he had and when it was gone, it was gone.
He has also helped me on a couple of other items and I have found him to be knowledgeable and truthful.
Not to beat a point down but Bill at Moyer's told me that there were no more flyback transformers for my CTC-21 in their stock and they were gone some time ago and didn't expect to see any more even in aftermarket versions. So if he gets a hold of a batch, does this mean he lied? No! That is the information he had to work with.
Same kind of situation. Even with the internet, no one can know exactly what is out there completely. There may be stashes of 15GP22 crt's out there we don't know about...who knows.
So basically, IMHO, no one lied to anyone on this situation and to call Scotty a liar on this issue, I think is a mistake in a situation that is destined to be forever in flux.
Just my 2 cents.
AUdubon5425 02-15-2009, 06:07 AM I received a quote from Hawkeye of $300 to rebuild my 23MP4. Truthfully, that is way over budget for me.
VDC told me they had 23MP4s in stock for $139, so I ordered one. Turned out that was an inventory error, but they had a substitute. That's fine, as long as it'll work.
So I get a 23EWP4, hook it up and all is well. Except they charged me the $139 for it while their advertised price for the 23EWP4 is $59.
I'm going to call them next week and see if they will refund the difference or give me a credit, as I plan to get a new tube for my little Philco.
John Marinello 02-20-2009, 12:38 PM I'm going to call him about my 23MP4 when my tax refund arrives.
Has anyone written up directions for the proper way to pack a CRT for shipping?
Video Display has 8 23MP4 CRTs, $139 per each, you could buy a spare for
what Scotty charges:
http://vdc.mybisi.com/product/56478/23MP4_416108.html
Eric H 02-20-2009, 01:36 PM Video Display has 8 23MP4 CRTs, $139 per each, you could buy a spare for
what Scotty charges:
http://vdc.mybisi.com/product/56478/23MP4_416108.html
Do not depend on their Site to give you accurate information on what's in stock.
They did not have any 12WP4'S in stock despite the Site saying they had 9.
jhalphen 02-23-2009, 05:46 AM Hi to All,
On the topic of CRT rebuilding, over here in Europe we are not sitting on our butts doing nothing!
Witness, for instance this rebuild by French Co. RACS of a very rare pre-war Telefunken tube model RFB/VI-1 for our friend Eckhard in Germany.
RACS gave me permission to post these pictures, so here they are.
Rebuild was routine, except for the electron gun which the Lab commented "Had the complexity of a "Rube Goldberg" device": successive interconnections of focussing grids in the sequence G1-G2-G1-G2-G1-G2
The gun was entirely rebuilt, using the original metal electrodes which were remounted in a "copycat" entirely new gun.
Other interesting comments: the supplied tube was down to air, so of course it was cleaned out to all transparent glass then new P4 phosphor was applied. RACS commented that the internal side of the faceplate was slightly damaged by the many years the CRT had been down to air, so minute internal surface irregularities can be seen (with your nose on the screen!) after recoating.
And, oh yes, the CRT glass is Pyrex and rebuilding involved the now mastered art of fusing "salami-slices" of different glass softness to match Pyrex to soft glass.
Each picture is named with the proper step description in the rebuilding sequence.
Next step in the project is "bring your dead CRT to the ETF Convention" May 1-2-3 for a bulk shipment of 10-15 tubes to France to save on shipping costs.
Best Regards
jhalphen
Paris/France
jhalphen 02-23-2009, 05:50 AM Telefunken pre-war CRT, 2 last pictures
John Marinello 02-23-2009, 08:50 AM I need to get my Predicta Holiday CRT to him, good idea on the tax return, that is what I will do with mine.
Dan
What CRT does the Holliday use? 17 incher?? If so, I may know someone who has an NOS one.
John Marinello 02-23-2009, 09:15 AM Hi to All,
On the topic of CRT rebuilding, over here in Europe we are not sitting on our butts doing nothing!
Witness, for instance this rebuild by French Co. RACS of a very rare pre-war Telefunken tube model RFB/VI-1 for our friend Eckhard in Germany.
RACS gave me permission to post these pictures, so here they are.
Rebuild was routine, except for the electron gun which the Lab commented "Had the complexity of a "Rube Goldberg" device": successive interconnections of focussing grids in the sequence G1-G2-G1-G2-G1-G2
The gun was entirely rebuilt, using the original metal electrodes which were remounted in a "copycat" entirely new gun.
Other interesting comments: the supplied tube was down to air, so of course it was cleaned out to all transparent glass then new P4 phosphor was applied. RACS commented that the internal side of the faceplate was slightly damaged by the many years the CRT had been down to air, so minute internal surface irregularities can be seen (with your nose on the screen!) after recoating.
And, oh yes, the CRT glass is Pyrex and rebuilding involved the now mastered art of fusing "salami-slices" of different glass softness to match Pyrex to soft glass.
Each picture is named with the proper step description in the rebuilding sequence.
Next step in the project is "bring your dead CRT to the ETF Convention" May 1-2-3 for a bulk shipment of 10-15 tubes to France to save on shipping costs.
Best Regards
jhalphen
Paris/France
Looks like there's a metal tube in the background, are they having good luck rebuilding those?
Also, can they aluminize tubes, and would a super-bright picture be somehow undesireable on a prewar set?
If they can aluminize tubes, how about metal CRTs? I heard that it was a difficult process due to the tight corner formed at the faceplate/cone bond. The specs on the 19AP4C states aluminized, but I've never seen one.
vintagecollect 02-23-2009, 10:45 AM I may have a CRT to send to you to france, it's gone to air , DO the rebuild CRT projector tubes jphalen? I need a single red phospor CRT projector tube rebuilt that has gone to air with an open filament??
please reply
jhalphen 02-24-2009, 08:04 AM Hi to All,
For John Marinello:
Q: Looks like there's a metal tube in the background, are they having good luck rebuilding those?
A: Will ask today
Q: Also, can they aluminize tubes, and would a super-bright picture be somehow undesireable on a prewar set?
A: Yes they can, in fact it's part of the normal routine. However, for TVs which have an EHT of less than 8kV, the screen is not aluminized. Reason? under 8kV, electrons don't have enough acceleration to get through the aluminum barrier, hence no picture or very dim picture. The 8kV limit was determined by experimentation + experience (RACS has been in operation for 35 years +)
Q: If they can aluminize tubes, how about metal CRTs? I heard that it was a difficult process due to the tight corner formed at the faceplate/cone bond. The specs on the 19AP4C states aluminized, but I've never seen one.
A: Will ask today, i'm fairly confident they can, over time they've dealt with a considerably variety of tubes, B&W and Color, consumer & military.
For Vintagecollect:
Q: I may have a CRT to send to you to france, it's gone to air , Do they rebuild CRT projector tubes jhalphen? I need a single red phosphor CRT projector tube rebuilt that has gone to air with an open filament??
A: will ask today. Tube ident, manufacturer & basic data would help.
please reply - Will do! as soon as i get answers.
2 things you all should know:
- I don't work RACS, nor have any business ties. Like all people on this forum i'm into vintage TVs, and when i learned that we still had a CRT rebuilding facility in France, it seemed an interesting challenge to nurture contacts between this Co. and the worldwide community. In other words, i help with all the language, translation & cultural aspects.
- RACS rebuilds tricolor CRTs, but like all companies in this trade, they cannot re-screen a tricolor tube. in other words, guns YES, screens NO.
Best Regards
jhalphen
Paris/France
jeyurkon 02-24-2009, 09:16 AM Hi jhalphen,
Additional questions: When they re-phosphor a P4 CRT do they use the original silver activated Zinc Sulphide + Zinc Cadmium Sulphide or do they use the modern cadmium free P4 replacement?
The modern replacement doesn't look as nice to me because the three components are randomly distributed when mixed. Since it's random it can't be perfectly uniform. You end up with colored blotches. I seem to be the only one that complains about this. Even a color CRT with a monochrome picture looks better to me because it is uniform. Oddly enough I have defective color vision but am still sensitive to this.
Actually, on a large CRT I'd be sitting back far enough to not notice it, but on a small 8" or even 12" it really shows up.
I understand the need to go to cadmium free phosphors, but if they're allowed to use the original for vintage or historical restorations, that would be great.
John
jhalphen 02-24-2009, 02:41 PM Good Evening Gentlemen,
Answers from RACS, today, late afternoon, France:
John Marinello has a sharp eye indeed to see a glass-metal tube behind the Telefunken! - see pix below.
Metal/glass tubes are no different for us than all-glass tubes. Of course, there can be problems of separation and cracks at the glass/metal boundary, these are known problems and we have means to solve them, not always, but frequently.
Successful rebuilding of glass/metal tubes:
Success depends on mastering stresses at the glass/metal boundary, we have good experience in this domain, but no one can guarantee a 100% success rate in this operation, old glass/metal has it whims and CRT rebuilding is a mix of science & know-how, therefore some fail.
Tube aluminizing:
Correction: OK for tubes at or above 12 kV EHT, not 8kV as quoted earlier. My mistake or new directive, i don't know.
Aluminizing metal envelope tube:
Aluminum is evaporated under vacuum inside the CRT. The vaporized aluminum is therefore deposited everywhere, but in this precise case, the aluminum deposit is only important on the screen, not on the bell, which being made of metal, already has excellent conductivity. If some aluminum is not deposited on the bell and there are bare spots, the EHT wiil circulate without problems and it is not a small bare spot which will impede its passage.
What is really important, is the quality of the Al deposit on the phosphor layer. if you look at the photograph, you will see that the evaporation filament is in the direct axis pointing at the screen. Nothing will prevent the Aluminum from being deposited wether the screen is all glass or glass/metal.
For Vintagecollect:
Awaiting your data on the Red projector CRT.
Best Regards
jhalphen
Paris/France
jhalphen 02-24-2009, 02:45 PM Good Evening Jeyurkon,
Questions duly Noted.
Will transfer tomorrow & hopefully expect fast reply.
Best Regards
JH/Paris
jeyurkon 02-24-2009, 08:13 PM Thanks for the photo of the CRT being aluminized. That's cool!
Is the orientation of the photo the same as how the CRT was oriented? That is, was it horizontal?
Most evaporation sources that use a boat would require the screen to be at the top, otherwise the aluminum would fall out of the boat. If they use a stranded tungsten coil that is wetted with aluminum, then I could imagine it being in the orientation shown.
John
eberts 02-25-2009, 02:43 AM How current are those photos ?
I saw a reprocessing plant in 1963 that used the same rescreening equipment in the USA.
The next year it was all scrapped and closed, color TV gained acceptance, killed the profits and the B&W customer base.
I remember B&W rescreened tubes could be purchased for $4.95 to $9.95.
The electron guns could be bought for 35cents each in quantity.
jhalphen 02-25-2009, 06:32 AM Hi to All,
Reply for Eberts:
> How current are those photos ?
Very recent, the telefunken tube was done a few weeks ago
> I saw a reprocessing plant in 1963 that used the same rescreening
> equipment in the USA.
Rebuilding tubes is a mixture of technology, know-how, and art. This was refined in the 50s and basically hasn't changed. A tube work station looks the same everywhere.
Now RACS is not a Mom & Pop operation using a DIY 1000$ kit like were widely sold in the US in the 60S. RACS is a small industrial outfit, been in business for 35 years, and have heavily stocked up on CRT components, glass, chemicals, etc. to continue offering the service for at least 5 years. BTW, they do a lot of MIL work for radar & head-up display CRTs.
Have a look at their site:
http://www.tube-cathodique.com
> The next year it was all scrapped and closed, color TV gained acceptance, > killed the profits and the B&W customer base.
RACS rebuilds B&W, monochrome (green, yellow,..computer screens) AND full color CRTs.
> I remember B&W rescreened tubes could be purchased for $4.95 to $9.95.
> The electron guns could be bought for 35 cents each in quantity.
Yes, well, those were the prices 50 years ago!
We are not trying to compete head-on with US rebuilders, but rather to offer an alternative when the US plants close down, in 2 years max, or less.
There is also a collector market in Europe, mainly the UK & Germany so far.
Best Regards
jhalphen
Paris/France
jeyurkon 02-25-2009, 08:45 AM Thanks, that link answered my aluminization question.
John
TubeType 02-25-2009, 09:25 AM Dear Jhalphen,
Thank you for acting as our intermediary with the folks at RACS. I find the Q&A about metal-glass monochrome CRTs very interesting.
Here are my questions for the engineers at RACS.
Can they successfully rebuild a 15GP22 CRT?
If yes, what is their price?
Kindest regards,
Terry Cheek
John Marinello 02-25-2009, 06:07 PM jhalphen,
Thank-you very much for your speedy replies!
RACS is doing some fine work, lets hope they will be around
for a long time!
-John
jhalphen 02-26-2009, 06:42 AM Hi! to All,
Follow-up answers from RACS on various inquiries:
Photo of CRT during aluminization operation:
The tube was indeed vertically mounted, screen at the top.
For John/Jeyurkon: P4 phosphors with/without Cadmium.
RACS comments that "you have one hell of an eyesight" to perceive such minute variations in P4 White qualities.
Just curious (me) what is the nature of your vision deficiency, Daltonism for instance?
To come back to the topic:
- Sure we still have Cadmium phosphors, for instance Yellow phosphors used in monochrome computer monitors are Cadmium based.
As for vintage P4 Cadmium phosphors, NOS inventories aren't kept for no good reason...
For Vintagecollect:
RACS confirms they routinely rebuild video projector CRTs.
Please supply data on your specific Red tube:
Tube type, maker, screen size, EHT (if known), base type...
For Terry Cheek:
Ah! the 15G, the Holy Grail of CRTs!
RACS is not ready yet, although would like to do this in the future. The ETF (Thanks! Steve) supplied a 15G gun assy from a broken tube for preliminary assesment. To go any further, RACS will need a complete dud tube, still under vacuum, if possible, and maybe more than one.
I had long discussions with RACS about the 15G's major plague, i.e. the leaking glass/metal junction. They have good experience in this domain, having encountered the same problem on other tubes they were asked to rebuild. We didn't go in depth about the details of resealing, but i understood that in general terms Frit glass is applied around the rim of the leaky glass/metal junction then hardened by baking. Afterwards, the CRT is evacuated, etc.
My friend John Folsom Jr is doing pioneering work in this domain along with Pete Deksnis and Bob Galanter. One tough questions remains on both sides of the Atlantic: as no CRT rebuilder can make a new tricolor screen, are the 15G phosphors still usable on a tube which has gone to air, usually for decades.
just FYI, a new gun, any gun, on which a new cathode has been installed and activated, is instantly destroyed by contact with air, even if brand new and never used. Are phosphors as vulnerable? no one knows until a rebuild is attempted.
To finish on a more positive note, RACS is also interested in rebuilding "easier" tubes than the 15G such as 21xxP22, the 21" roundies which ruled supreme for a decade between 1955-1965. Providing the tubes are still under vacuum, no major theoretical stumbling block is anticipated as RACS has the expertise to rebuild B&W and Color electrons guns in-house
Best Regards
jhalphen
Paris/France
electroking 02-26-2009, 08:32 AM Dear jhalpern,
Please note that the term 'daltonism' is not usually understood in English.
They just call it 'color blindness'. One of those instances where our French
language is more concise than English...
jeyurkon 02-26-2009, 10:32 AM Dear jhalpern,
I'm PM you about this since it's way off topic. But interesting to me...
John
jeyurkon 02-26-2009, 03:45 PM At least some recent CRT color phosphors are applied with a chromated hydroxycellulose. That's a water based photosensitive material. I would find it difficult to believe that any phosphor that stands up to water would be bothered by exposure to air. Once baked on moisture shouldn't bother them much either.
Prolonged exposure to moist air could damage the aluminization. Aluminum is a fairly reactive metal when not protected by its oxide layer. Particles of carbon, or possibly the phosphor, could cause corrosion in moist air.
So, I think you're right to worry about air, but the phosphors themselves should be stable. IMHO.
I use the red CRT phosphor that is used in color CRTs to make beam viewers. The phosphor is applied as a water solution and we bake them in air with no ill effects. However, we don't aluminize them.
I think the statement that "no one knows until a rebuild is attempted" is still correct.
John
TubeType 02-27-2009, 08:57 AM Dear jhalpern,
Please note that the term 'daltonism' is not usually understood in English.
They just call it 'color blindness'. One of those instances where our French
language is more concise than English...
The term "Daltonism" is derived from the name of the English chemist and physicist, John Dalton. Dalton was born in 1766, in Cumberland, England.
John Dalton described his and his brother's affliction of colorblindness with defective perception of red and green in the first scientific paper he published. It was entitled Extraordinary facts relating to the vision of colors, with observation. It is the first recognized account of red-green colorblindness.
Dalton's reputation largely rests upon his law of partial pressures and his Atomic Theory.
Terry Cheek
jhalphen 02-27-2009, 01:40 PM Hi Jeyurkon, John,
you wrote:
"I use the red CRT phosphor that is used in color CRTs to make beam viewers. The phosphor is applied as a water solution and we bake them in air with no ill effects. However, we don't aluminize them."
I'm interested! what sort of beam viewers?
Let me guess: IR laser beams? - Power?
Are you using Y2O2S:Eu, the standard P-22 Red phosphor?
A few years ago, Radio-Shack sold an IR viewer plastic strip to test remote controls. Works quite well in the dark, a few inches away.
Best Regards
jhalphen
Paris/France
jeyurkon 02-27-2009, 07:36 PM Yes, it's Nichia's NP-1154 Y2O2S:Eu Red crt phosphor.
I work at the National Superconducting Cyclotron Lab. The viewers are used to image the accelerated ion beams at various stations along the beam line.
The plastic IR strips are interesting. Another way that I found accidentally uses a CCD camcorder. I was using my Sony Handicam and was surprised to see how bright the IR led in my TV remote looked when I happened to catch it in use.
John
jeyurkon 02-27-2009, 08:05 PM In case I haven't already convinced everyone that I don't live in the real world these ideas probably will fix that.
It seems to me that metal ring that causes leaks in the 15GP22 actually might make it one of the easier color CRTs to attempt to re-phosphor. No doubt someone has probably already thought of this and why it won't work, but since I'm a newbie I want to bounce these ideas off of the forum.
Assuming that Bill Gates wanted a 15GP22 re-screened and said that money is no object, the procedure would go something like this:
Bring the CRT up to air, or verify that it is up to air.
Remove the weld on the metal ring. Machining or abrasive techniques would be a bit risky so the safest way would be to EDM the weld. We don't care about the electrolyte getting into the CRT since we're rebuilding it.
After separating the bell from the faceplate remove the decorative mask, phosphor-dot-plate and shadow mask.
Remove the gun from the bell. Clean the faceplate and bell removing all of the dag. Now would be the time to repair any problems with the glass-frit.
Clean the phosphor-dot-plate removing all of the phosphor.
Now we need some fixturing to accomplish the following. We also need some supplies and decide what type of phosphors to use. I had to purchase some CRT Red Phosphor for work. It was Nichia NP-1154 Y2O2S:Eu. The minimum was 1kg at a cost of $1.5K. You might want Phophors to match the original emission spectra though.
The first phosphor is mixed with a photosensitive polymer and appropriate binding agent. It is placed onto the phosphor dot-screen and spun to evenly distribute. After drying, the shadow-mask is assembled with screen. A UV point light source is positioned in the same position as the appropriate gun for the particular phosphor and the polymer is exposed. This hardens it. The screen is then washed and only the polymer and phosphor that was exposed remains. The original method involved a separate silk screen exposure but this method is more precise.
The screen is then baked. The process is repeated for the remaining two phosphors.
At this point you might want to apply a black coating to surround all the dots, but after getting this far I don't think it's worth the risk.
Now a lacquer is applied. Then the dot-screen is placed in an evaporator and a layer of aluminum is evaporated on to it. I would bake the screen again, probably in vacuum or inert gas to remove the lacquer at this stage. It would be easier to fix now if there is a problem rather than after the crt has been reassembled.
The decorative mask, dot-screen and shadow mask are now assembled with the faceplate.
In the meantime the bell has had aquadag reapplied to the inside.
The bell and faceplate are reassembled in the proper orientation. Then the metal rings are TIG welded again. This is a critical operation but can be done by hand by an experience welder. If it's done improperly the frit-glass may crack and leak.
I would then helium leak test the assembly and repair any leaks. A coating of solder-glass or frit glass painted on to the glass metal transitions would be a safety measure and then fused at the appropriate time.
The new or rebuilt gun would be added now and the CRT processed following normal re-gunning procedures.
Enough of my crazy ideas. But they're here for you to shoot holes in them.
I was amazed at how much information is available on the web for the 15GP22
John
vintagecollect 02-28-2009, 01:01 AM Quest International Inc.,, 65 Parker, Irvine, CA 92618
Quest International's technicians are highly trained and certified to perform Cathode Ray Tube - CRT refurbishing on the most antiquated CRTs - Cathode Ray Tubes as well as the most cutting edge CRTs Cathode Ray Tubes.
Quest International offers a wide range of services for all CRTs - Cathode Ray Tubes - particularly refurbishing and re-gunning. Quest International has a fully qualified staff to provide technical support on any Cathode Ray Tube - CRT issues. Quest International's loaner program can minimize any downtime by providing a replacement CRT - Cathode Ray Tube while your CRT- Cathode Ray Tube is getting repaired.
:thmbsp::yes::scratch2:
jhalphen 02-28-2009, 12:01 PM Hello to All,
Jeyurkon, i love your project!
I offer to scan in the IRE's 1951 "Special Color TV issue" the article describing the step by step production of the 15GP22's screen & post it on PhotoBucket to ensure adequate size & readability.
Can only do this after March 8th as i am at the CABSAT Broadcast show all next week.
Best Regards
jhalphen
Paris/France
jeyurkon 03-01-2009, 01:40 PM I hope I didn't give the impression that this is a project that I'm working on. It's just that it seems that there are no places that rephosphor CRTs. Besides the cost I wondered if there were any other reasons it couldn't be done so I started to think about how I would do it.
There also needs to be a reason for doing it. If there are few color CRTs that need to be rephosphored, then there isn't much motivation to set up for it.
Having said that, it's pretty amazing what resources some hobbyists have. Though any one individual might not have all of the skills or equipment, some set of them might.
I'm still amazed every time I watch Claude Paillard's video where me makes a triode vacuum tube.
John
jeyurkon 03-04-2009, 08:27 PM I did a quick and dirty test of the slurry screening technique. I used Nichia's NP-1154 red phosphor. The phosphor was suspended in a dichromated polyvinyl alcohol solution. I used potassium dichromate instead of ammonium dichromate which the recipe called for. Sodium dichromate should also work.
I spread the slurry onto a glass slide and let it dry. I then placed a metal mask over it and exposed it with a UV lamp. It was then developed by letting hot water run over it.
The results can be seen in the attached image. In the center there is an array of dots partially surrounded by a circle. The dots are spaced with a 600 micron pitch and are about 150 microns wide.
You can see problems with it. I was surprised it worked this well. The main reason for the damaged areas is due to the thickness of the coating. The optimal coating thickness is 1.4 phosphor grains. I didn't want to set up a spin coater for this test because of the work involved in cleaning it up afterwards. A spin coater will give a very uniform easily controlled thickness.
When the coating is too thick, the UV light is completely absorbed by the phosphor before reaching the surface of the glass. The result is that there is a PVA layer that doesn't get hardened. This layer softens and releases the hardened layer above it when developed. With the correct thickness, the PVA would have been completely hardened down to the surface and the phosphor would have remained where the PVA was exposed. In this case, some of the areas floated away.
The difference in the horizontal and vertical resolution of the dots also has to do with the thickness. The water was flowing horizontally across the slide and was able to flow undisturbed between rows. The material between columns was protected by the height of the dot in the preceding column. If the coating was as thin as it should have been, then the features wouldn't disturb the flow nearly as much.
It would also have helped to treat the glass so that it was hydrophilic. The most effective means would have been to evaporate a coating of silicon dioxide on to the surface. Another method would have been to clean the glass in a solution of potassium hydroxide and isopropyl alcohol.
BTW, the plate was illuminated with UV light to cause the phosphor to fluoresce when the photograph was taken. Otherwise, the phosphor would have looked white.
It's a simple matter to improve the process to the point of being able to apply the three phosphors using the shadow mask. Whether it would be profitable for a company is another matter.
I had fun in any event.
John
bgadow 03-04-2009, 10:20 PM The last line is important! You could have lots of creative fun with all that is at your disposal. Next thing we know, you'll have built your own custom color crt!
mikeh 03-05-2009, 11:57 AM Hi,
I don't really want to change the subjet after all the interesting technical information on custom color crt's.
I contacted vdc the other day and recieved a reply that they no longer regun 21 inch color crt's like the 21fjp22. I was looking at all options that are still available for rebuilding. Has anybody else contacted them abount round color crt repair, since Steve did in the earlier post.
Mike
jeyurkon 03-05-2009, 12:27 PM I think I'm the one that drifted off topic. I should have started another thread. Yours is more pertinent to the original thread.
John
Hi,
I don't really want to change the subjet after all the interesting technical information on custom color crt's.
I contacted vdc the other day and recieved a reply that they no longer regun 21 inch color crt's like the 21fjp22. I was looking at all options that are still available for rebuilding. Has anybody else contacted them abount round color crt repair, since Steve did in the earlier post.
Mike
old_tv_nut 03-05-2009, 04:54 PM Hi,
I don't really want to change the subjet after all the interesting technical information on custom color crt's.
I contacted vdc the other day and recieved a reply that they no longer regun 21 inch color crt's like the 21fjp22. I was looking at all options that are still available for rebuilding. Has anybody else contacted them abount round color crt repair, since Steve did in the earlier post.
Mike
Have no info on vdc, but wondering why you don't contact Scotty if vdc says they no longer do it.
mikeh 03-05-2009, 05:41 PM Good point, I was just checking out options, $450 to $500 is big money to me.
To preserve some of these marvels of technology from the past for future use it, is now time to just pay up and get it done while it is still possible. I will contact Hawkeye and pay up. :D
Mike
ohohyodafarted 03-05-2009, 06:14 PM RE: 15GP22 issues.
I am working with John folsom on the 15Gp22 rebuild project.
1. There should be no issues with the viability of the phosphors regardless of whether or not the crt is under vacuum. So long as the tube has been sealed, (IE; the neck is not broken off) the phosphors should be usable.
2. Someone stated that electron guns exposed to air instantly get destroyed. That is true only for electron guns that have been activated with the RF bomber. Guns that have not had the cathodes activated are not subject to the instant destruction from air.
3. John and I have done a very through analysis of the leak issue on the
15GP22. It is our belief that the leakers have gone to air not from the glass to metal seal, but from 2 metal to metal joints that exist in the manufacture of the ultor ring. And I am NOT speaking of the arc welded joint that holds the front and rear halves of the crt together. Although frit is used in the sealing of glass to metal, and glass to glass, frit must be matched very closely to the expansion coefficients of the glass and metal or the frit will not hold. ON our project we have found an alternative material to conventional frit, that is used to seal fiber obtic glass threads into connectors that must hold a vacuum. This material will be used in the not to distant future when we attempt to do another rebuild of the 15GP22. We are currently working on some issues that need to be resolved before the next attmpt takes place. We will keep this community informed if and when we have some successes to report.
jeyurkon 03-05-2009, 08:49 PM It sounds like you guys are making some real progress. :thmbsp: It's great that you're so dedicated to the project.
If you, or anyone, has a 15GP22 that has gone up to air and isn't otherwise rebuildable I think I could arrange to helium leak test it and determine exactly where the leaks are. I wouldn't be anxious to risk a CRT, that could be rebuilt, by having it shipped.
By any chance is the sealing material that you're referring to F113? A water thin epoxy used for bonding fibre optics into connectors? If it is F113 or a similar epoxy, I do use it for forming vacuum tight connections when I have to fabricate my own, but these are on actively pumped devices.
I don't know that I would recommend it for a permanently sealed vacuum because of its outgassing properties. On the other hand, the exposed area must be extremely small since you're repairing a leak, so it might still outlast the normal life of the CRT.
John
vintagecollect 03-05-2009, 10:05 PM Consider doing that project soon and giving some money for his efforts at Hawkeye. Scotty said it's been slow lately, Just wanted to give everyone a heads up and started this thread. I need to follow up and see if he has the tech info to do a rebuild project of mine.
:thmbsp:
WISCOJIM 03-06-2009, 07:46 PM Hi,
I don't really want to change the subjet after all the interesting technical information on custom color crt's.
I contacted vdc the other day and recieved a reply that they no longer regun 21 inch color crt's like the 21fjp22. I was looking at all options that are still available for rebuilding. Has anybody else contacted them abount round color crt repair, since Steve did in the earlier post.
Mike
Who did you speak to? I was in contact with Erv from VDC less than a month ago about these. Here is his reply to me dated February 10, 2009:
"Jim:
Received your request for CRT types 21FBP22 and 21FJP22A.
At this time we have no stock of either type. It is possible to rebuild these if good duds are made available. Cost of rebuilding would be $250.00, excluding freight.
Thanks,
Erv Kuczogi
Video Display Corporation
White Mills, PA 18473
Phone: 570-253-3910
Fax: 570-253-3912
vdcwm@ptd.net"
mikeh 03-06-2009, 10:27 PM WISCOJIM
Thanks for your information. This is the same person I corresponded with via email, three days ago and Erv replied that they no longer rubuild these tubes.
I will contact them by phone next week and ask them about rebuilding, there may have been a miscommunication on my part. The cost of $250 plus freight makes it alot more afordable for me.
Mike
WISCOJIM 03-07-2009, 08:45 AM WISCOJIM
Thanks for your information. This is the same person I corresponded with via email, three days ago and Erv replied that they no longer rubuild these tubes.
I will contact them by phone next week and ask them about rebuilding, there may have been a miscommunication on my part. The cost of $250 plus freight makes it alot more afordable for me.
Mike
Let's all hope you get good news back. Either way, be sure to let us know.
mikeh 03-10-2009, 12:28 PM I talked to Erv at VDC today on the phone and was informed they no longer rebuild the round color crt's. So I now is the time to get off the fence if you need a tube rebuilt.
Mike
jeyurkon 03-17-2009, 10:09 PM Scotty just rebuilt a pair of 12LP4A CRTs for me. They test great! He does really nice work.
It'll be a bit before I can put one into a set, but I'm sure they'll perform well.
John
jhalphen 03-20-2009, 06:07 PM Good day, Gentlemen,
Follow up on the RACS rebuild of a Telefunken RFB-VI-1 pre-war CRT.
This tube was rebuilt for a collector friend of Eckhard residing in Germany.
Here are some screen shots of the CRT reinstalled in the original TV chassis sent by RACS.
On Feb 23rd of this same thread, pictures were shown of the rebuilt CRT ready to leave the factory. These are proof-of-the-pudding pictures that the rebuild was entirely successful.
Best Regards
jhalphen
Paris/France
jeyurkon 03-20-2009, 07:36 PM Thanks for the update. That's pretty nice work. How many transistions in the glass did they need to handle the pyrex?
Also, what is the "bring your dead CRT to the ETF for rebuild project?" Is this for a specific CRT type or any one that can't be dealt with in the US?
John
jhalphen 03-24-2009, 06:28 AM Hello to All,
Hi Jeyurkon,
Pyrex adapter intermediate glass rings:
Talked to RACS yesterday. Philippe, the Manager said "from memory, 2 to 4 rings". His brother is the Tech Manager but was out of the office otherwise i would have got a precise answer. I can inquire if you want to know precisely.
About this:
Also, what is the "bring your dead CRT to the ETF for rebuild project?" Is this for a specific CRT type or any one that can't be dealt with in the US?
Basically, the project as of now is for any rebuildable B&W CRT. So far, there is strong interest in 12AP4's and 30BP4's in lower quantities for this second reference.
We are having problems with the shipping prices quoted for the ETF (Columbus, OH) to France & return. Several members here have found cheaper shipping cost directly from their location to France.
If you take into account that the bulk shipment of tubes returning to Columbus must then be re-shipped one by one from there to wherever the final user lives, this again adds to the total shipping budget.
To work in complete transparency, here are some figures we have been quoted recently:
9 x 12AP4 tubes from ETF to France (ONE way)
300 lbs, 1 pallet, total size 56" L x 40" W x 56" H, each CRT individually boxed.
price Euros 987.00 - US $1337.58
1 x 20BP4, boxed, size 22.4" x 22.8" x 32.3"
San José (CA) --> France, Euros 390.00 - US $528.52
Same CRT, France --> San José, Euros 291.00 - US $394.36
Eu/$ conversions at today's currency exchange rate: 1 Euro = US $1.3552
http://www.lemonde.fr/web/eco/devises/0,58-0@2-3234,1-0,0.html?NAV1=MAR&NAV2=DEVISES
The CA Gentleman (Hi Tom!) was quoted US $163.00 for USPS shipping from his location to RACS, clearly a very competitive price!
We are therefore now working on getting quotes from the French Post Office "La Poste" for the return shipments from RACS to any US location for individual CRTs.
Will update as more info comes in...
Best Regards
jhalphen
Paris/France
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