Getter used up but tube is fine.

I still have a large box of 2D21 & 2051's from my days in elevators. Anybody remember the ''Touch-Button'' tubes for calling?And the toolkit for relay adjusting? It still brings a smile to my face when I think back to riding on top of a car when I was a kid.Imagine the hippie tree-hugger shitstorm we'd have for doing something like that today.General Elevator of Canada,rip:(
 
One more issue.

The getters in the majority of tubes are not consumed as the OP described. We have tubes that run for thousands of hours and, absent an envelope failure, the getter is as pristine and beautiful on the day it dies as when it left the factory.

RCA spent a lot of effort creating efficient getters, and I've read the papers and patents. Mountains of work went into creating high quality getters and this shows in the quality of the NOS tubes which have not gone to air in the decades of storage or use.

Again, the OP's tubes are being driven too hard and endogenous or exogenous gas is destroying the getter. Something clearly is wrong in that circuit.

It could be as simple as the fact that the shorter envelope of the 5933 doesn't radiate heat as well as the 807. I have never had the getter of an 807 fade in this amplifier like the way it happened to these 5933s. Or it could be that late production early 80s tubes aren't the same quality as their predecessors.
 
Man I've actually seen those elevator control panels with a few tubes in them, I think they were 6SN7s or some kind of thyratron. Watching one of those old electromechanical elevator controllers in a large building work during a busy time of day, is fun, dozens of open frame control relays sparking, away as floors are requested, and the massive cam turning as the elevator goes up and down. Otis really had some imagination when they figured out how to control elevators. I wonder if any of them are still in service, or if they've all been converted to digital.

See above ^^^^^^^^
 
I still have a large box of 2D21 & 2051's from my days in elevators. Anybody remember the ''Touch-Button'' tubes for calling?And the toolkit for relay adjusting? It still brings a smile to my face when I think back to riding on top of a car when I was a kid.Imagine the hippie tree-hugger shitstorm we'd have for doing something like that today.General Elevator of Canada,rip:(

Cool! I never got to work on elevators, I always thought it looked like an appealing job though, it seems like such a regulated industry without a ton of competition, and elevator rooms are neat, especially the really old ones.

Did those old Otis capacitive touch buttons employ thyratrons too? The ones where the whole panel would light up if it was too dry.
 
It's actually the other way around. Lower demand lowers prices. At some point the mines and manufacturing shut down, prices rise enough, mining and manufacturing resume.

Tungsten is relatively abundant, although the easy mines have long since been exhausted; refining, however, is expensive. Yet even then it still doesn't cost that much and a tube contains a tiny amount.

This is why Toffler lost his bet. We now have replacements, mostly plastics, for the metals he thought would skyrocket in price. As prices rise substitutes will generally be found.
^

Jac,you are missing my point here.This has absolutely nothing to do with the availability of material,mining or refining. It has everything to do with subsequent processing.How many applications require precision-drawn tungsten wire? Believe me,when the last nail is in the incandescent coffin,good luck finding the finished WIRE, not the tungsten.
 
^

Jac,you are missing my point here.This has absolutely nothing to do with the availability of material,mining or refining. It has everything to do with subsequent processing.How many applications require precision-drawn tungsten wire? Believe me,when the last nail is in the incandescent coffin,good luck finding the finished WIRE, not the tungsten.

Halogen lamps will be around a while yet, it's not banned yet and still widely used.
 
It could be as simple as the fact that the shorter envelope of the 5933 doesn't radiate heat as well as the 807. I have never had the getter of an 807 fade in this amplifier like the way it happened to these 5933s. Or it could be that late production early 80s tubes aren't the same quality as their predecessors.

All good explanations. Can also be internal design of the plate.

The 807 tended to have a short life in the television horizontal output stage. Those tubes often look terrible.
 
Cool! I never got to work on elevators, I always thought it looked like an appealing job though, it seems like such a regulated industry without a ton of competition, and elevator rooms are neat, especially the really old ones.

Did those old Otis capacitive touch buttons employ thyratrons too? The ones where the whole panel would light up if it was too dry.

Yes,they used many,many thyratrons and ignitrons.I don't know if the TB tubes carried over into the solid state era.It was really longgggggg ago
 
All good explanations. Can also be internal design of the plate.

The 807 tended to have a short life in the television horizontal output stage. Those tubes often look terrible.

What TV used an 807? I know some early sets did use the 6BG6, which is more or less an octal base 807, but I've never seen a schematic of a tv with an 807 in it.

The plate of the 5933 does look different than an 807 too, the 807 having the classic original 6L6 type plate straight out of rca literature.
 
This has absolutely nothing to do with the availability of material,mining or refining. It has everything to do with subsequent processing.How many applications require precision-drawn tungsten wire? Believe me,when the last nail is in the incandescent coffin,good luck finding the finished WIRE, not the tungsten.

Tungsten wire is used for heaters in all sorts of applications and is still used in transmitting tubes and x-ray tubes.

I expect it to be commonly available for a very long time.
 
What TV used an 807? I know some early sets did use the 6BG6, which is more or less an octal base 807, but I've never seen a schematic of a tv with an 807 in it.

After WWII some TVs used 807s because of low-cost surplus. The 6BG6 is roughly equivalent which was my point. Any of the horizontal output tubes (maybe also 6CD6? and 6CB5?, can't remember) tended to die a rapid and horrible death from overwork. That application treated it as a consumable, and the vaporized getter looks like what happens in a TV.
 
After WWII some TVs used 807s because of low-cost surplus. The 6BG6 is roughly equivalent which was my point. Any of the horizontal output tubes (maybe also 6CD6? and 6CB5?, can't remember) tended to die a rapid and horrible death from overwork. That application treated it as a consumable, and the vaporized getter looks like what happens in a TV.

6BQ5, 6DQ6, etc for black and white television, then for colour 6LF6 and other huge compactron tubes. They do look pretty bad after extended hours, but still manage to last a while, especially the newer designs.

I've worked on lots of old TV sets but never something from the 1940s, up here in western Canada we were behind the curve, no TV until after 1950, so first generation televisions are impossible to find here. It would be very cool to have a TV with an old war surplus 807 as the horizontal output. I spend half my free time during the holidays this year watching documentaries about world war two, it's unreal how many resources went into it.
 
Halogen lamps will be around a while yet, it's not banned yet and still widely used.

Oddly enough,I have been wanting to get rid of the PAR 20 halogen bulbs at mine and the GF's place for some time. I have never been happy with the amount of heat they generate vs the amount of light they output.About the only advantage is the focused beam.In the summer it's like a burger sitting under the heat lamps at Harvey's:mad:

I just found led equivalents at the dollar store and wallymart too. Buck and a half at both places.They actually seem a lot brighter too,with virtually no heat,and far lower power consumption.Available in warm white and daylight models.Installed a bunch above one of my workbenches; WOW!!
 
6BQ5, 6DQ6, etc for black and white television, then for colour 6LF6 and other huge compactron tubes. They do look pretty bad after extended hours, but still manage to last a while, especially the newer designs.

Right. Those tubes are the ones that resemble the vaporized getter, so it stands to reason the dilapidated appearance is from exceeding limits of the device, regardless of what is published for sales purposes.

I've worked on lots of old TV sets but never something from the 1940s, up here in western Canada we were behind the curve, no TV until after 1950, so first generation televisions are impossible to find here. It would be very cool to have a TV with an old war surplus 807 as the horizontal output.

Those TVs are easy to work on; nothing in them. But try to find a CRT...
 
The RCA paper by Thomas is, alas, not as enlightening as one would hope. That is a great academic resource, but in this instance the material tends to be more theoretical and background than empirical from typical usage. It does not describe the phenomenon above detailed other than to note that the reactions slowly proceed after initial flashing. I tried to find a paper discussing the reactions after, say, a thousand hours of use but could not find any papers on that, from RCA or others. The patents weren't much better.
 
Can someone take a photo and actually point to the Getter, what is it ? where is it? is it a coating?
 
Now that's a scary thought. I'm sure someone will be building one just for that purpose.

BillWojo
 
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