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#1
02-10-2009, 04:30 PM
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Does anyone know if Scotty can rebuild the 7DP4 for the 621TS?
The electrostatic focus makes it an oddball. 
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#2
02-10-2009, 04:29 PM
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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
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#3
02-10-2009, 05:03 PM
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I had Scotty rebuild a 7DP4 quite a few years ago. If he still has (or can get) guns, he cn rebuild them.
__________________
John Folsom
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#4
02-11-2009, 06:46 AM
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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 .
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#5
02-11-2009, 01:13 PM
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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.
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#6
02-15-2009, 06:07 AM
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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.
__________________
AUdubon5425 Youtube Channel
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#7
02-26-2009, 08:32 AM
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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... Last edited by electroking; 02-26-2009 at 08:32 AM. Reason: corrected spelling
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#9
02-27-2009, 08:57 AM
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Lost In Translation
Quote:
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
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#10
02-27-2009, 01:40 PM
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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
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#11
02-27-2009, 07:36 PM
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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
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#12
02-27-2009, 08:05 PM
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15GP22 rescreening ideas
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
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#14
03-05-2009, 11:57 AM
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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
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#15
03-05-2009, 12:27 PM
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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 Quote:
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Hybrid Mode
