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Old 05-24-2013, 01:55 PM
7jp4-guy 7jp4-guy is offline
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Gathering data on CRT rebuild value

All -
I think it would be very useful to this project to poll collectors on how much they would be willing to pay to have CRTs rebuilt. Knowing this will give us a good idea of how feasible the business side of the operation is, one of the important questions that needs to be answered as we try to get this up and running. To this end I propose that we create a poll on the matter and link to it in the various TV forums to collect data. However, before I do this I would like some feedback on what others think of the idea and how I might go about actually creating such a poll.

First, what CRT types should we ask about? I propose:
3KP4 (Pilot TV-37 tube)
7DP4 (621TS tube)
17DRP4 (Predicta tube)
21EAP4 (Predicta tube) (Thanks bandersen!)
15GP22 (CT-100 tube)

Second, for each of these tubes what price ranges should we ask about? For all but the 15GP22 I propose options of:
$100 - $200
$200 - $300

For the 15GP22 I propose:
$500 - $1000

Third, how would one go about creating such a poll? I don't think this forum or the have the advanced poll options we would need.

Thanks for your input.


Last edited by 7jp4-guy; 05-24-2013 at 02:52 PM.
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Old 05-24-2013, 02:38 PM
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bandersen bandersen is offline
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Good idea. I'd like to add 21EAP4 (predicta tube) to the list. I have three that need rebuilding. A growing pile of 10BP4s and 12LP4s too.

Just to give you some idea what it used to cost - Hawkeye was charging $300 for a 10BP4 right before he closed.
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Old 05-24-2013, 03:19 PM
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Electronic M Electronic M is offline
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I propose adding the 21" color Roundy tubes.
21AXP22(this is the most challenging type of 21" color tube to find or rebuild, likely of similar difficulty to the 15GP22)
With how many folks collect these sets and how often folks are looking for roundy CRTs adding these to the list is a no-brainer.

Some of the 25"(23" viewable) and smaller size rectangular delta gun color tubes such as the 25GP22 might also be good to add. More and more folks are collecting them, and sooner or later the few NOS CRTs and parts sets with good tubes to pirate will dry up.
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Old 05-24-2013, 04:09 PM
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miniman82 miniman82 is offline
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I know the purpose of this forum is the exchange of ideas, but the cart in these posts so far is being placed WAY TOO FAR in front of the horse.

Can we please deal with reality for a moment?

We don't even have a rebuilding station built, much less a solid place nailed down to set it up in. That makes talk of which CRT's to rebuild very premature, to say the least.

I think everyone thus far is running on the assumption that ETF will be the place, and I don't think anyone disagrees about that. That makes the next point of discussion what the station will look like. Bob made up a drawing I like, so let's build that.

Now all we have to do is get together and build it! Easy right? Not really, if that were so it would be done already. Everyone LIKES the idea of being able to rebuild tubes, but thus far there has been ZERO heavy lifting on getting anything actually DONE. That's because no one so far has surveyed the proposed location at ETF, or drawn up any plans to follow.

So I guess what I'm getting at here is, stop skipping straight to 'GO' when we haven't even left 'Reading Railroad' yet. The first course of action at the moment needs to be working towards a solid set of building plans we can follow, then we can start moving stuff around, running wires/pipes, ect. Once the station is built, we can move on. Everyone in favor of 'Operation build a CRT Station'?

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Old 05-24-2013, 06:24 PM
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I'd pay $500 each for my two 30BP4 CRTs to be rebuilt. I'd also pay $75 each for about eight 3KP4s I have to be rebuilt. I have six 21" roundy CRTs I'd pay $250 each to be rebuilt.
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Old 05-25-2013, 08:00 AM
tvdude1 tvdude1 is offline
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What about the GUNS the important part. Where will you find them?
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Old 05-25-2013, 08:41 AM
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Hi All;

I am happy to see progress on the picture tube rebuilding program getting underway. I think for the sake of getting an idea on a price point and demand for tubes 7jp4-guy is just doing some market research here on demand and getting some idea on where a budget may begin to take shape.

We can imagine that Hawkeye's prices gave him coverage of costs, plus a profit to put into his being able to live. We can equate that profit to funds to keep the tv museum and the crt rebuilding station open.

That said, I think prices should be at least at first based upon what Hawkeye was charging, and of course you may have to add to that for the replacement of consumables that will grow harder to acquire as more crt companies close their doors.
I would imagine he can even give you a starting point on demand for certain types of tubes. This community can do that as well. Just start a sub page "how many of you have tubes for rebuild" Add your type, quantity, max price payable.

I would also assume, that as the crt rebuilding station is set up the first tubes will have a high failure rate due to contamination, and the fact that this "art" can not be perfected by watching the movies on youtube. I would imagine color tubes may be a few years away, and that more common B&W tubes will be the first tubes to see rebuilding success and any amount of volume production.

It is impressive to see the grand size of the station drawing. It assumes a large volume of tubes will be processed. I sure hope this can be accomplished, but I think a small less expensive test size room might be a smarter way to go, save some cash.

I am very pleased to see the crt rebuilding project make VK its home (I hope) for news. Previously any news was quite sporadic, and scattered very unorganized across several websites and un-updated for a few years in some cases, even as these sites upon launch proclaimed to be the new location for news on the project.

I would also like to see a repository of knowledge collected, on the process, chemistry, machinery, all of it, here so that the knowledge can be accessed and improved upon by individuals who may not be near the station, but may have usable ideas for the project. I have enjoyed seeing and reading, and watching the youtube procedures of the attempts with the 15G that have been posted over the years. Each new posting I find seems to contain a little bit more information on the complexity of the procedure. I for one, would like to be able to read about and understand the entire procedure of crt rebuilding.

I think in the long run, the guns will have to be rebuilt by you guys, not just rebuilding the tubes, so that is something you will have to think about while allocating space for the project.

The possibility of rebuilding guns means that maybe recovery of the cut off old gun needs to be thought about now. When cutting off a gun you now have a replacement for, may mean that old gun should be saved, and stored in a clean, vacuumed, and sealed storage locker.

Thanks for bringing the crt rebuilding project news and progress reports to VK.
Yes you can call me "Squirrel boy"

Last edited by Username1; 05-25-2013 at 08:45 AM.
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Old 05-25-2013, 09:38 AM
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Steve McVoy Steve McVoy is offline
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Progress report:

Geoff Bourne has agreed to be the project manager for building the room at the museum where the equipment will be located. He visited after the convention, took measurements, and we discussed ideas for construction.

He will put together drawings and a bill of materials. I have agreed to price the materials so we know how much money we'll need for this project.

Geoff will select a date for pouring the floor, and bring the necessary tools. We should be able to get that done in a weekend.

Then, another date will be set to build the room.

Chuck Azar will be in touch with those on the email list, and dates will also be posted on this forum.
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Old 05-25-2013, 01:15 PM
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John Folsom John Folsom is offline
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Something else to think about. It does no good to have a rebuilding plant if we have no guns or cathodes & teems to rebuild guns, along with the required fixturing.

We may have some guns from Hawkeye, and maybe some more from RACS at some future date. There may also be some guns available from Southwest Vacuum, if it is not already too late.

It is unlikely we will be able to rebuild 3KP4/7JP4 CRTs, because there are no guns and no stems available, at least that I am aware of.

But Nick is correct, we must wake before we run.
John Folsom
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Old 05-25-2013, 02:03 PM
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N2IXK N2IXK is offline
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What became of Tektronix' CRT operations when everything went LCD? Perhaps a gun adaptable for the electrostatics might be available ?
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Old 05-25-2013, 02:37 PM
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ChrisW6ATV ChrisW6ATV is offline
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If the project is to be done entirely for its own sake as a historic/educational exercise, then even one or two working CRTs per month at amortized costs of $2000 each or more is fine. If the project is specifically planned from the start as a self-sufficient business, then the questions of what people are willing to spend (and how many customers may exist, even) are very worthwhile. Fifty CRTs at $150 each over one year would not have a chance at paying the bills.

I would expect (or hope) that the project will end up somewhere in between my two examples, if it does succeed: CRTs rebuilt at time and material costs, but with lots of volunteer work and/or donations as well.

Ultimately, the value of a new picture tube in a set depends heavily on the value or desirability of the set itself. $300 is a lot of money just to get a brighter picture in a typical late-1940s 10-inch RCA TV, but $500 to get a 21-CT-55 or Muntz 721CV working again is almost a no-brainer to me.

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Old 05-25-2013, 05:00 PM
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Eric H Eric H is offline
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I agree the thing needs to get built before even talking about pricing but... it was $300 for a normal B&W from Hawkeye.

I expect it is going to be much more expensive if it's done on a smaller scale for vintage tubes only, this is just something we'll have to live with if we want tubes for our old sets.

I doubt if it matters much if a CRT is 3 inches or 21 inches, the work and materials are the same, and honestly a 3KP4 is generally a much more desired tube than a 21" B&W (except a Predicta of course) so price being commensurate with size is not likely, like any business the retail price will ultimately depend on what the process costs to operate.

If Guns have to be hand rebuilt then I can imagine it being way more expensive.
It might turn out that the only practical application for a rebuilding station will be for Pre-war tubes and early color where price is no object.
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Old 05-25-2013, 10:20 PM
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bgadow bgadow is offline
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Only 2 or 3 people are every likely to get good enough at it to do the rebuilds; will they all be local to the museum, or will they have to fly in a do a few on a weekend? As volunteers, they aren't going to be too excited to sweat out, say, a 10BP4, knowing it won't net any profit for the museum...or for them. The 10BP4, most 21" b/w's, all 18v/19v/23v/25v would be a very long time before the demand would be there. I suspect that once everything is set up, most of the time will be spent on the "heavy-hitters", 15GP22, 21AXP22, 30BP4, the Predicta tubes would be easier and a good source of income. Personally, I'm not sure if I'll ever be well heeled enough to pay what it's worth to rebuild, say, a 3" Pilot crt.
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Old 05-26-2013, 06:12 AM
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miniman82 miniman82 is offline
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I have no idea where I'll be in life when I retire, but I hope it won't be too far from the museum...
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Old 05-26-2013, 09:01 AM
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jhalphen jhalphen is offline
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Hi to all,

Hello Nick,

I am worried about one essential step in the CRT rebuilding process: rebuilding the guns. For most of our vintage tubes, NOS ready to install guns simply do not exist, therefore the only way is to take apart the original gun, replace the filament(s) + cathode(s), then reassemble.

This is no mean feat: the entire electrode structure must be taken apart then reassembled in 3D space with perfect spacing & alignment geometry. We're talking fractions of millimeters in all 3 dimensions here. The issue is not only rebuilding a working gun, it must conform to the original specs for it to work perfectly in a vintage TV.

Imagine for instance that an original focus voltage called for 800 Volts but that the rebuilt gun focussed correctly only at 1000 Volts. The TV's circuitry would need to be modified or the CRT rebuilt again. And this is just one parameter among a myriad that can veer off course.

Not trying to be a kill joy here, but just trying to convey how difficult it is to do if you don't have the luxury of just taking a NOS gun out of a bin.

Two years ago, i queried François R. at RACS about doing an inverse operation to Nick's coming to France: if the ETF CRT plant was installed & ready, would he come to the US as a consultant to teach the art of gun rebuilding + iron out the bugs as the facility started to operate? the answer was "why not".

That was 2 years ago. Still i think that someone with 40 years experience in CRT/gun rebuilding would be invaluable to shorten the learning curve of the new facility.

In RACS's 35 years of operation, even when the plant had 30 employees, François R. was the only person who took apart & reassembled guns.

Would Hawkeye's Scotty accept to do this? his residing on US soil would really make things easier/cheaper.

Best Regards

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