UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Websites

Notices

Websites Found an interesting website? Post the details here and share it with the rest of us. Please stick to websites that are in some way related to our hobby/interest.

Closed Thread
 
Thread Tools
Old 14th Dec 2021, 8:14 am   #1
Keith956
Heptode
 
Keith956's Avatar
 
Join Date: Jun 2019
Location: Oxfordshire
Posts: 719
Default Home made valves

Apologies if this has been posted before, but came across this fascinating Youtube of a French guy that makes his own valves. Not only are the valves home made, but it appears his valve making equipment is also!

https://www.youtube.com/watch?v=EzyXMEpq4qw
Keith956 is offline  
Old 14th Dec 2021, 10:20 am   #2
greenstar
Octode
 
greenstar's Avatar
 
Join Date: Jul 2011
Location: Leicester, Leics. UK.
Posts: 1,681
Default Re: Home made valves

There's also this chap:
https://www.youtube.com/watch?v=oSgVGwqJ2Jk
http://tubecrafter.com/index.html

And there was somebody in Poland, on YT in Polish, https://www.youtube.com/watch?v=PjTaLsM6Hbo&t=398s
I think this is the right video ... he posted on the American forum, but I lost the link.


Way beyond my present capacity, but fascinating.
greenstar is offline  
Old 14th Dec 2021, 12:21 pm   #3
broadgage
Nonode
 
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 2,129
Default Re: Home made valves

I think that the first link may have been posted previously, but some considerable time ago and well worthy of repeating.

Making the electrodes of a valve is not that hard, the main challenges are in glass working and achieving a high vacuum.
broadgage is offline  
Old 14th Dec 2021, 1:09 pm   #4
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Home made valves

I wonder if anyone has tried home made valves using metal envelopes??

Brazed copper for the outer envelope / anode construction would be good from the heat dissipation perspective. Anyone got access to a turbomolecular pump
__________________
I'm the Operator of my Pocket Calculator. -Kraftwerk.
G6Tanuki is offline  
Old 14th Dec 2021, 1:44 pm   #5
kalee20
Dekatron
 
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 7,061
Default Re: Home made valves

It would need good removal of brazing flux though, and thorough leak detection testing before building-up and attempting to pump-out. I can see the attraction of glass!
kalee20 is offline  
Old 14th Dec 2021, 2:48 pm   #6
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,801
Default Re: Home made valves

Firing a getter in a metal valve must be rather inconvenient, so I assume they must be pumped all the way down?

Etch-clean parts to be brazed in an inert atmosphere, keep there while brazed under induction heat. No flux needed.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is offline  
Old 14th Dec 2021, 2:58 pm   #7
GrimJosef
Dekatron
 
Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 4,310
Default Re: Home made valves

Quote:
Originally Posted by broadgage View Post
... the main challenges are in glass working and achieving a high vacuum.
How about making a durable cathode with decent emission at acceptably low temperature, and winding grids which stay mechanically stable in the sort of conditions that prevail in power valves ?

Cheers,

GJ
__________________
http://www.ampregen.com
GrimJosef is offline  
Old 14th Dec 2021, 3:17 pm   #8
ms660
Dekatron
 
ms660's Avatar
 
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
Default Re: Home made valves

Construction of a 6K7 "metal valve" etc, page 2:

http://www.nj7p.org/Manuals/PDFs/Tub...RC-14-1940.pdf

Also:

http://www.r-type.org/articles/art-018.htm

Lawrence.
ms660 is offline  
Old 14th Dec 2021, 5:36 pm   #9
Guest
Guest
 
Posts: n/a
Default Re: Home made valves

Looking at the 6K7 the "Batalum" getter is twixt two pins in this case anode to an unused pin, it wouldn't matter if it was an active pin, the short circuit is meant to be blown up anyway. I guess it is a heater surrounded by getter, heat up getter evaporates, big current the short disappears. Ingenious.
 
Old 14th Dec 2021, 5:52 pm   #10
ms660
Dekatron
 
ms660's Avatar
 
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
Default Re: Home made valves

It's not a 6K7 per se but it shows the typical construction of those types of metal valves of which the 6K7 is one, apologies for any confusion.

Lawrence.
ms660 is offline  
Old 14th Dec 2021, 5:54 pm   #11
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: Home made valves

I guess that you could maybe re-work and stretch out 12-volt 21-Watt car brake-light bulbs for use as 'directly-heated' filaments - running them off reduced voltage since you don't need them to emit visible photons. Could some high-emission coating [Thorium?] be electro-deposited on the existing coils to get the electrons flowing more freely? A directly-heated rectifier capable of delivering quite a few milliamps of HT should be possible this way.

Envelope-construction - remember the Osram "Catkin" valves from the 1930s. Laser-welded, water-jacketed stainless-steel envelopes would seem to be the 21st-century version.

And what about making a triode along the lines of the UHF 'Planar' ones from the 1950s; flat cathode, flat stressed-mesh grid and flat anode should simplify the whole 'mechanical rigidity' thing.

Sealing the lead-outs through insulators would be my big problem: glass 'eyelets' were the solution for the 1930s/40s RCA metal valves, but it had all gone ceramic by the time the likes of the 4X150A came on the scene.

Though I did a week-long 'laboratory glassware' course at Uni, I can weld much better than I can 'blow' Quartz/silica or Borosilicate glass!
__________________
I'm the Operator of my Pocket Calculator. -Kraftwerk.
G6Tanuki is offline  
Old 14th Dec 2021, 11:06 pm   #12
Bear2Biker
Triode
 
Bear2Biker's Avatar
 
Join Date: Jan 2011
Location: Bradford, West Yorkshire, UK.
Posts: 43
Default Re: Home made valves

Search for "Glasslinger" on YouTube and you will find several decent quality videos of him making diodes, nixies and triodes, he seems to have all the right equipment on a small scale & he covers the failures too.
__________________
Bear2Biker
Bear2Biker is offline  
Old 15th Dec 2021, 1:32 pm   #13
ms660
Dekatron
 
ms660's Avatar
 
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
Default Re: Home made valves

Quote:
Originally Posted by merlinmaxwell View Post
Looking at the 6K7 the "Batalum" getter is twixt two pins in this case anode to an unused pin, it wouldn't matter if it was an active pin, the short circuit is meant to be blown up anyway. I guess it is a heater surrounded by getter, heat up getter evaporates, big current the short disappears. Ingenious.
The getter material holder will remain intact, in the drawing shown in that link it forms the connection between the valves metal envelope and shield and Pin 1.

Lawrence.
ms660 is offline  
Old 15th Dec 2021, 2:36 pm   #14
jhalphen
Hexode
 
Join Date: Jul 2004
Location: Paris, France
Posts: 346
Default Re: Home made valves

Hi to all,

AlekZ from Poland has built a 7 tube UltraDyne radio using Audion lookalikes he built himself :

https://antiqueradios.com/forums/vie...ef69cf5ed0fb88

Also is experimenting with CRT building:
http://www.videokarma.org/showthread.php?t=273434

Built himself a Monoscope test pattern CRT tube:
https://www-pwl-mikrokontroler-pl.tr...en&_x_tr_hl=en

The chap's resumé:
https://www-pwl-mikrokontroler-pl.tr..._x_tr_sch=http

Best Regards
jhalphen
Paris/France

Last edited by jhalphen; 15th Dec 2021 at 2:41 pm.
jhalphen is offline  
Old 15th Dec 2021, 11:14 pm   #15
bigfathairyvika
Hexode
 
bigfathairyvika's Avatar
 
Join Date: Nov 2009
Location: Cambridge, Cambridgeshire, UK.
Posts: 489
Default Re: Home made valves

Quite a few years ago I was lucky enough to watch Gerry Wells make a valve in his shed/conservatory.
He made it look easy.
bigfathairyvika is offline  
Old 16th Dec 2021, 10:34 am   #16
Guest
Guest
 
Posts: n/a
Default Re: Home made valves

Quote:
The getter material holder will remain intact
But it could be blown up if the pin was needed.
 
Old 16th Dec 2021, 11:47 am   #17
ms660
Dekatron
 
ms660's Avatar
 
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
Default Re: Home made valves

Quote:
Originally Posted by merlinmaxwell View Post
Quote:
The getter material holder will remain intact
But it could be blown up if the pin was needed.
Why blow a connection that's needed, the only connection to the metal envelope is Pin 1 in the valves I've encountered.

Here's what the tube manufacturer (RCA) says about it (Mag. page 318, 2nd Para.):

https://worldradiohistory.com/ARCHIV...w-1940-Jan.pdf

Lawrence.
ms660 is offline  
Old 16th Dec 2021, 1:12 pm   #18
Guest
Guest
 
Posts: n/a
Default Re: Home made valves

Indeed,, just a thought...
 
Old 16th Dec 2021, 4:28 pm   #19
Hartley118
Nonode
 
Hartley118's Avatar
 
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,196
Default Re: Home made valves

Quote:
Originally Posted by bigfathairyvika View Post
Quite a few years ago I was lucky enough to watch Gerry Wells make a valve in his shed/conservatory.
He made it look easy.
I recall a few years back when Gerry proudly showed a couple of us round his museum, he pointed out some of the valve evacuation kit and indicated an ambition to manufacture small quantities of valves. Can anyone brief us on what happened to that project?

Martin
__________________
BVWS Member
Hartley118 is offline  
Old 16th Dec 2021, 5:31 pm   #20
Guest
Guest
 
Posts: n/a
Default Re: Home made valves

Here https://hackaday.com/2016/01/09/buil...blinker-fluid/ is an interesting triode.
 
Closed Thread

Thread Tools



All times are GMT +1. The time now is 3:08 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.