Sciencemadness Discussion Board

Platinum electrodes from Radio Vaccum Tubes?

ktw_100 - 28-4-2006 at 09:33

I was just wondering about getting platinum from the anodes/plates of some larger vacuum tubes from old radios. Seems to me that the grids in these tubes might be good for making electrolysis anodes/cathodes. Also, what about other larger CRT's. Anybody ever tried this?

12AX7 - 28-4-2006 at 10:11

Hmm, not familiar with Pt- they're usually nickel, copper or tungsten. Nickel is preferred for a lot because it outgasses easily in processing. Of course, Ni isn't nearly expensive enough to tear up poor old tubes for.

Tim

The_Davster - 28-4-2006 at 14:35

I read your post this morning, then this afternoon I had the opportunity to acquire dozens of vaccuum tubes for free:D. I don't really need them, but I am a sucker for free stuff....

Would have been nice if they did contain some precious metal...

a_bab - 29-4-2006 at 13:03

They usually contain a very small quantity of Ba, with the role of degasing. You can see it on the oposite side of the pins, as a blackish mirror deposited on the glass.

12AX7 - 29-4-2006 at 16:15

FWIW, the ring (or strip or whatever) that the barium is evaporated from, I've tried induction heating the getter inside sealed tubes and nothing appears to come off, it's a good bet they evaporate everything at manufacture.



Tim

The_Davster - 29-4-2006 at 16:50

Tim in your picture I am assuming it is of a tube being beld in a coil for induction heating?

To get slightly off topic, what is the basic design of your induction heater Tim? I have been thinking of making one with a NST, 15kv, 1uf cap, and a spark gap.

12AX7 - 29-4-2006 at 18:45

http://webpages.charter.net/dawill/tmoranwms/Elec_IndHeat6.h...
Also check out the other pages. You'll find that pic on the 2nd page or so.

In particular, I think that was a 12AT7 type.

Tim