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-   -   CRT Rebuilding update (http://www.videokarma.org/showthread.php?t=270328)

miniman82 04-10-2018 09:17 PM

CRT Rebuilding update
 
There have been some recent developments regarding the rebuilding effort, so I think an update is in order.

You all know by now that a successful rebuild attempt was made during last years ETF convention: I completed a 17CP4 metal cone tube that is still holding vacuum today, which proved the basic operation of the equipment at the museum. That tube mistakenly had a gun with a 12v filament installed in it, we still don't know how that happened but at least the tube works. In the future it will be easy to check the heater of the guns before installing them, to make sure that doesn't happen again.

Recently I made a trip to LA to purchase a large inventory of tubes and rebuilding equipment from a company called Quest International. They are still in business, just not with tubes anymore. The tube inventory is being sold on the ETF site, so if you need anything in the way of B&W or color in a square glass format contact the museum. They have a part number list of what I brought back with me, and we're working on getting technical data on them. These were used in medical imaging, high res stuff.

The rebuilding equipment was brought back to my place here in Southern Maryland, for two very good reasons:

1. I can't be at the museum full time rebuilding tubes, and only 2 weeks a year during convention time rebuilding tubes helps no one. We would only get 1, maybe 2 tubes like that.

2. I'll have complete quality control over every step of the rebuilding process here at home, it will be my retirement job. I'll also be customizing the equipment to suit my needs, which should help increase output as much as possible.


This doesn't mean the stuff at the museum goes to waste, I'll still be there at the meet demonstrating the equipment and it's still perfectly viable machinery if someone wants to learn on it. I made the decision to go after the stuff on my own dime in the best interests of the community, because I can better serve customers when the equipment is near me instead of in Ohio.

Doing any actual work is still a ways off, I have to complete outfitting my garage for operations and set up all the necessary utilities like electrical power and gas/air lines. Safety is a concern for me as well, so I'll likely wind up with fire hoods over the pieces with open flames to make sure I don't burn the place down. Should make the insurance people happy as well.

I'll post more updates as they become available, but for right now know that I'm committed to bringing an effectively dead service back to the community in the not so distant future. I just hope you collectors out there are ready to uphold your end and actually buy some tubes. lol

Nick

Dubis7 04-10-2018 09:38 PM

Where are you in Southern Maryland? I'm in Northern VA. Dunno how much help I could be right now, but I can't imagine it would hurt to have someone learn to use some of this stuff at 21.

Actually, come to think of it, as a recently graduated film student, do you think it would be a good idea to do a sort of documentary on the process? Having sort of edu-video of tube rebuilding would help preserve the knowledge for the future. I'm a screenwriter myself, but I know people who make documentaries.

AlanInSitges 04-14-2018 09:05 AM

That sounds like a pretty great idea. There was a long video shot shortly before Hawkeye shut down; it's interesting (for the handful of us that are obsessed with this stuff and actually understand what's going on) but I think it would be dull and way too dense for most people.

There was a long piece on The Verge not along ago talking about vintage TVs (kinda) and that touched on the subject as well. The article was pretty much a shitshow, written by someone who appears not to understand the distinction between a CRT and a TV that uses a CRT. But it was widely circulated and discussed, and I think it's a subject that would be fascinating to a large number of people, provided it were a well told story with a narrative and so on.

I think you should try to do it.

Robert Grant 04-15-2018 01:05 AM

Quote:

Originally Posted by miniman82 (Post 3198097)
I completed a 17CP4 metal cone tube that is still holding vacuum today, which proved the basic operation of the equipment at the museum. That tube mistakenly had a gun with a 12v filament installed in it, we still don't know how that happened but at least the tube works.

Maybe you should write the EIA (or successor of same) for the designation of this unique tube.

Looking at Frank's tube site, the last 17" CRT code was the 17EZP22*, so I guess you have the world's only 17FAP4.

*noting the real oddity of the 17QCP(n) series available with many different types of phosphor.

Dave S 05-08-2018 10:42 AM

Quote:

Originally Posted by Dubis7 (Post 3198099)
Where are you in Southern Maryland? I'm in Northern VA. Dunno how much help I could be right now, but I can't imagine it would hurt to have someone learn to use some of this stuff at 21.

Actually, come to think of it, as a recently graduated film student, do you think it would be a good idea to do a sort of documentary on the process? Having sort of edu-video of tube rebuilding would help preserve the knowledge for the future. I'm a screenwriter myself, but I know people who make documentaries.

There is a bit of information available, but unfortunately no formal video documentation / training film of the process.

Bob Galanter documented Scotty performing the operations at Hawkeye and I put his video online. Jerome Halphen and Nick Williams also recorded video of Nick's apprenticeship at RACS before they closed, which I have posted in unedited form.

https://www.youtube.com/playlist?lis...Uwq-L41psfpLJQ

If we ever have Scotty come by to do training at the museum I do plan to make a full, formal documentation of the process and his instructions.

I'd gratefully accept any assistance you'd be willing to offer regarding Early Television Museum videos.

-- Dave Sica 732-382-0618

user181 05-08-2018 10:47 AM

CRT Rebuilding update
 
Has Scotty been approached about coming to the ETF Museum to do training? If say a formal invitation/request should be made (if it hasn't already).

Dave S 05-08-2018 10:54 AM

Quote:

Originally Posted by user181 (Post 3199228)
Has Scotty been approached about coming to the ETF Museum to do training? If say a formal invitation/request should be made (if it hasn't already).

Need to have someone for him to train, and right now there is no one who has stepped forward as a candidate. Nick is currently the only person in our circles who knows how to do this and he's already quite skilled enough that bringing Scotty out to work with him would not be worthwhile.

user181 05-09-2018 10:44 AM

Quote:

Originally Posted by Dave S (Post 3199230)
Need to have someone for him to train, and right now there is no one who has stepped forward as a candidate. Nick is currently the only person in our circles who knows how to do this and he's already quite skilled enough that bringing Scotty out to work with him would not be worthwhile.


I see. I wish I could contribute to this in some way, but I'm a newbie in the arena of TV repair and lack the domain experience with this stuff.

I've watched the videos of Scotty doing the rebuilding and I can see that it is the kind of work that you probably need to do a lot of to get good at it. It also seems to be the sort of thing that is learned through "tribal knowledge" and can't be taught through books & videos alone.

BBTV 05-13-2018 08:39 AM

Have you considered writing a manual on "how to do it" ?? It seems like this is a lost art, that you and the museum are hoping to ressurect. Might be a good idea to see that it does not get lost again. I can volunteer to edit, proof, and even write from notes, but I have no experience with either glass or making tubes, although 'back in the day' I sure installed a lot of them.

I am in Ohio, and am currently working on restoring the museum's TK41 color camera. Working on a test equipment museum of my own, so I cannot, sadly, step up to learn the tube making process, much as I'd like to help out in this effort, but perhaps I can contribute in an educational way.

Barry

tvcollector 07-29-2020 11:42 PM

There hasn't been an update since mid 2018... I'm assuming these projects have all been forgotten.. So much for getting these duds rebuilt.. Oh well I guess landfill it is..

trinescope 07-30-2020 08:58 AM

I have some of my own opinions and ideas on this subject. To me, the glassworking aspect is the most difficult part of the entire process. From what I have been reading, the high temperature bakeout is not strictly necessary, and is mostly to get shorter pumpdown times. There is no economic pressure to get product shoveled out the door quickly, so doing low temperature bakeout could cause fewer problems related to that. Also, there are improved diffusion pump oils and vacuum pumps available now that will help get a better vacuum than was possible in the past. Why settle for good enough if a better result is possible and would pay dividends in longer tube life?

It seems to me there is a bit of impatience growing in the vintage TV community about not being able to get a CRT rebuilt. Not on my part, but only stating what I have seen lately.

Electronic M 07-30-2020 10:52 AM

Duds take up a sizable chunck of space. All my monochrome duds are crunched up in the landfill, same for all rectangular color duds. I gave away my glass roundy color duds that I haven't seen make a raster (since that's the only way to confirm the shadow mask and phosphor aren't damaged) and now only have 2 weak monochrome CRTs, 3 round glass colors (21FBP/FJP22), 1 maybe 2 21AXP22s and a 15GP22 waiting a chance to get rebuilt... I'd have no problem sinking ~$1200 into rebuilding the 3 21" color CRTs I've got if the service was available.
If I lived closer than 8 hours drive from the ETF I'd probably volunteer a weekend a month to learn the process and do rebuilds for them...I can't see it being profitable to pay someone to do it but if I donated my time a rebuild has to be worth more to the owner of a CRT than the materials and equipment running costs. If I had more space and fewer high dollar life goals I'd probably try to get my own rebuilding equipment. It's amazing to me that the ETF can get enough voulenteer time and effort to build a rebuilding shop but nobody is willing to take time to do actual rebuilds...There ought to be someone in the region with time on their hands and interest in keeping CRTs going.

It also amazes me that shops that currently rebuild modern CRTs won't take the job... you'd think if we got 10-100 CRTs of the same type like 21FBP22, 10BP4 or 12LP4 that some company would see it as a big enough job to be worth while.

trinescope 07-30-2020 12:30 PM

The longer this goes on, no ability to have a CRT rebuilt, the more potential rebuild candidates will end up in the trash instead.

I would need to acquire a vacuum setup with the ability to measure the vacuum to try out things like low temperature bakeout. I have only a junky HVAC pump, and that of course is not enough for this kind of work. I don't know if any of the mom and pop type rebuilding equipment came with high vacuum gauges. So much of the information I find about procedures looks rather empirical to me; it just says pull a vacuum for so much time, then activate the cathode according to a time schedule. It would be better to measure the vacuum and determine when to do things according to that rather than an empirical guess based on time.

Also, I would like to see if gun rebuilding can first be done on a monochrome tube, which should be easier and serve as a proof of concept. IMO too much time and effort was spent on 15GP22 tubes, these should be left for last after getting proficient with monochrome tubes first, then the all glass color tubes.

pdr-fml 07-31-2020 03:10 PM

Potential candidate
 
I always though something like this would be ideal for that Glasslinger guy on YT. The guy has lots of glass experience and seems to be highly intelligent although it is just one guy and up in years at that.

MRX37 07-31-2020 05:54 PM

Ooooooohhhhh Oh this sounds great. A CRT re-builder would be somewhat in demand given the retro gaming niche and collector niches...


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