research
 Patents
 Books
 Literature
 Articles
 Timeline
 Auction Archive

about
 About this site
 Wanted to buy

bulb gallery

Incandescent:
C
carbon
WD
drawn tungsten
WC
coiled tungsten
WM
mini tungsten
WS
pressed tung.
FG
figural bulbs
XL
christmas
XS
christmas sets
T
tantalum

Discharge:
NE
neon lamps
AR
argon lamps
XE
xenon lamps
MA
mercury
MC
fluorescent
MS
special mercury

Hardware:
F
fuses
FX
fixtures
PF
plugs & fittings
SA
sockets
SW
switches

tube gallery

 X-ray
 Geissler
 Crookes
 Radio
 Box art

museum pics

 Dr. Hugh Hicks
 
Fort Myers, FL.
 S.Slabyhoudek

links

 Related links
 Submit a link

 

Author Topic: custom made carbon filament  (Read 11229 times)

Offline marcin

  • New Member!
  • *
  • Posts: 1
custom made carbon filament
« on: December 01, 2011, 03:19:28 pm »
Hi All

This is my first post. I am an electronics hobbyist and a vacuum tube collector. During the day I am a computational biologist currently living and working in Norway.
My current Id?e fixe is recreation of the original Fleming diode. One looking just like this. The problem with this tube is that it uses a carbon filament.
I am asking The Wisdom of This Forum for help on how to get such a filament. The filament is horseshoe shaped, approx. 25mm tall, 8-10mm wide and runs on approx. 12V (neither of these values are very critical).
I looked the Internet up and down and found that basically I have two options: Either I scavenge filament from those new-made carbon filament lamps and trim it down, or I make my own from scratch. Scavenging of course seems simpler. But if I learned anything in my life is that the simple way seldom works. ;)
Creating one from scratch would require a lot of effort: creating cellulose filament, likely by squirting, carbonizing it, and then flushing. Especially flushing seems tricky as it looks that it should be done in atmosphere of hydrocarbons and hydrogen. Still I believe it is doable. And of course there remains a small task of gluing a carbon filament to the metal lead wires.

Could anybody offer any opinion, suggestion or know-how?
Thanks,
  Marcin