Cool DIY Vacuum Tube Video

For the design and construction details of ion guns, necessary for more advanced designs and lower vacuums.
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Mark Rowley
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Cool DIY Vacuum Tube Video

Post by Mark Rowley »

I thought everyone here may get something out of watching this video. It shows (quite elequently) how easy it is to make your own vacuum tubes. It starts off with the guy cutting stainless anode / cathode parts with a Swiss Army knife. The small spot welder is nice also. Anyway, the video gave me some assistance with some ion gun construction I have been attempting lately.

Give it a "look-see"!

http://www.grump.org/2008/01/on-eleganc ... tubes.html

Mark Rowley
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Steven Sesselmann
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Re: Cool DIY Vacuum Tube Video

Post by Steven Sesselmann »

Wow!

Thanks Mark, I enjoyed watching that, that guy was amazing, looked as if he had made all his tools too.

Inspirational!

Steven
http://www.gammaspectacular.com - Gamma Spectrometry Systems
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Re: Cool DIY Vacuum Tube Video

Post by myID »

Thanks for sharing... That guy is an artist- and he looks like one too
richnormand
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Re: Cool DIY Vacuum Tube Video

Post by richnormand »

Just spent an hour browsing the site.
Excellent
This is superb and a real inspiration.
Nice find, thanks.
DaveC
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Re: Cool DIY Vacuum Tube Video

Post by DaveC »

I'll just add my thanks, too, Mark. Very interesting site. The glassblower's art is indeed fascinating.


Dave Cooper
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Carl Willis
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Re: Cool DIY Vacuum Tube Video

Post by Carl Willis »

Very interesting video.

Towards the end, we get a brief glimpse of the dude's vacuum system, which is not at all conventional. It looks like he has built a Sprengel pump or some close variant involving flowing mercury.

The regenerative receiver is cute.

Surprising to see this tube in a UHF tuned-plate circuit of some kind, maybe an oscillator, made with what looks like a piece of 300-ohm feedline magnetically coupled at the shorted end with to a pickup loop of the same stuff. If that circuit works, it speaks quite highly of this tube's high-frequency capabilities!

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Re: Cool DIY Vacuum Tube Video

Post by Mxeno »

Have a look at his site
http://paillard.claude.free.fr/triodes/ ... ompes.html
He did also a very clever molecular drag pump, with a simple conical rotor enclosed between 2 stators with a spiral engraving. The motor is in the foreline vacuum.
Homemade molecular drag pump! Respect!

- Marc
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Re: Cool DIY Vacuum Tube Video

Post by DaveC »

C'est Magnifique!! Whew boy... my limited French vocabulary was put to the test., reading the descriptions.

But very interesting site....that's quite some DIY talent showing there.

The last photo's caption.. indicated 20 microns ( actually .020 mb) which would seem to be the working pressure of the combined system.. molecular drag (?) and a two stage piston pump.

Thanks Marc.

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Re: Cool DIY Vacuum Tube Video

Post by Mxeno »

From the index page
http://paillard.claude.free.fr
there is a link to the Google translator
then go to Triodes in the first list, then pumps...
Bonne lecture!
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Steven Sesselmann
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Re: Cool DIY Vacuum Tube Video

Post by Steven Sesselmann »

Did any of you notice that the wire feedthrough for the grid, had some kind of coating on the section that was squashed in the glass. I have seen this on light bulbs too.

I assume it is something to make the glass bond to the metal, but does anyone here know what it is?

On this subject, has anyone here ever tried to make a fusor sealed inside a glass bulb?

I know this was attempted here at Sydney Uni, but I am not sure if it succeeded. As far as I know, it was a request by the local science museum, who wanted a neutron producing demonstration fusor without the hassles of a vacuum pump.

Steven
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Re: Cool DIY Vacuum Tube Video

Post by John Futter »

Steven
From my earlier training as an instrument maker 30 odd years ago I did as part of it 3 months of scientific glass blowing.
depends on what glass the final is but an intermediate with differing thermal expansion is required between the tungsten wire and the final glass or is it Kovar wire which would require a different intermediate.
From memory platinum wire is compatible with pyrex directly-- or was it soda glass or quartz

don't quote me

for the first time in thirty years I did a little glass bending 3 months ago to make some annealing supports for our substrates in the vacuum furnace for annealling at 600 degrees, made of pyrex.


ruined a few days later by the students who thought it was made of quartz and took it to 1000 degrees celsius melting it to the furnace quartz tube which imploded during cooldown because of the differing thermal expansions.

I'll go and talk to the glass blower next week and find out about it and if he has any.
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Richard Hull
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Re: Cool DIY Vacuum Tube Video

Post by Richard Hull »

A useful tip relates to sealing electrodes to glass.

Platinum is compatible with most all glass as is, provided it is of small diameter.

Likewise, very thin tunsten welding rod is also useable with glasses, but it has to be treated with sodium nitrite at high temps. .010 rod stock is good. Tim Raney of our group here does this a lot. Tim now tends to use the classic graded seal using small dabs of uranium glass beads.

U glass is readily found on larger used hydrogen thyratrons and other large vacuum tubes at hamfests. Smash them and either keep the graded seal or just the U glass.

Cheaper still might be vaseline glassware. I haven't tried it yet as a graded seal, but about $40.00 will get you a large item from an antique store that would make thosuands of such seals. The U glass marbles that used to be on ebay might serve also.

Graded seals are real pretty and can take a good deal of heating (expansion and contraction without failure as witnessed in the old glass H2 thyratrons that run really hot. Some number to look for 4C35, 5C22. The 5C22 is still avaialble commercially for $1195.000. I found two at a recent hamfest of $2.00 each.

Richard Hull
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The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Re: Cool DIY Vacuum Tube Video

Post by DaveC »

The standard metals for inexpensive glass feedthroughs are Kovar and Dumet which more or less match the thermal expansion of soft glasses. As Richard notes small diameter Tungsten is also a close match for soft glass seals, as is Patinum. As I recall, the key is to have a wettable outer surface for the wire lead. For Tungsten, this is some sort of oxide.

Rosebury' Book on Vacuum Tube materials and Techniques, has some useful tables of thermal expansion for various glasses as well as the metal types the match reasonably well.

One reasonably good source for feedthrough stock, is any discarded incandescent bulb. Not sure how good a seal this is for extended high vac applications, but definitely works for about 1000 hrs more or less.

I think, you can still buy graded seals, but can't remember where... sorry... But the price is a lot more than that of a stray U glass jar from a junk shop. A lead borate glass is routinely used in CRT e-gun bases.

Dave Cooper
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Re: Cool DIY Vacuum Tube Video

Post by teslacoil.it »

I recently played with glass.


After some research, i found a great source of cheap dumet wire that match with neon signs manufacturing glass tubes........ many small diodes (eg 1N4148 or some zeners if bigger terminals are needed) are made with glass; just wipe terminals with sandpaper to remove tin/lead layer and you are ready to play with glass!


i attach some pics of my creations, please note, i'm NOT a real glass blower, i'm just play with some glass, flames and vacuum!

http://img213.imageshack.us/img213/3345/tubows4.jpg
http://img442.imageshack.us/img442/4971 ... odoyk7.jpg
http://img209.imageshack.us/img209/1269 ... uranl4.jpg

http://img444.imageshack.us/img444/8743 ... adeoy1.jpg
http://img205.imageshack.us/img205/2734 ... do2py2.jpg



Equipment used:

some torches
http://img241.imageshack.us/img241/858/fiammeco8.jpg

anealing oven
http://img329.imageshack.us/img329/4391 ... 30cxm0.jpg

Spotwelder
http://img364.imageshack.us/img364/1323 ... ce1hf2.jpg

some spotwelded items!
http://img88.imageshack.us/img88/1606/e ... aticz4.jpg
http://img216.imageshack.us/img216/5540/puntataiu7.jpg
http://img257.imageshack.us/img257/5877/geogrid1jn4.jpg
http://img443.imageshack.us/img443/2739/geogrid2od4.jpg


Little off topic here...... my new fusor chamber!
http://img217.imageshack.us/img217/6510/iosferaip4.jpg


Ciao!
Fabio!
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Steven Sesselmann
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Re: Cool DIY Vacuum Tube Video

Post by Steven Sesselmann »

Fabio,

Nice setup, I am impressed!

Have you considered building a sealed glass fusor?

Steven
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Re: Cool DIY Vacuum Tube Video

Post by teslacoil.it »

YES of course!

But these tubes are my really first glass works with positive results, actually i haven't neither the skill nor the material/equipment required to blow a larger tube, generally the glass crack during the cooling down defeating all the work!

anyhow, work in progress, i recovered some unused getters, these are able to achieve high degrees of vacuum inside of a permanently sealed tube even with a simple dual stage pump; a sealed-glass fusor (deuterium filled!) will made when i'll be able to achieve it.

Ciao!
Fabio.
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