[HomeBrew] DIY Vacuum Tubes!

[Robert Farmer]

This reminds me of the time, 1957, a friend and I grew our own crystal, 
ground it, and attached leads.  Thus was born a diode for our receiver.

73,

Robert, WB9UFM



Chickens are good for cleaning cat boxes.
Sage sayings of OneOldGoat
----- Original Message ----- 
From: "James Kearman" <jkearman at att.net>
To: <homebrew at mailman.qth.net>
Sent: Wednesday, January 09, 2008 4:01 PM
Subject: Re: [HomeBrew] DIY Vacuum Tubes!


> ** Please do NOT cross-post messages when posting to HOMEBREW **
>
> DavidE Benedict wrote:
>> DIY Vacuum Tubes!
>
> When I was a kid and didn't know it couldn't be done, I made what I 
> believe was a working "vacuum" tube diode. I used a Mason jar, in which I 
> rigged a circular anode around a nichrome-wire heater/cathode. I sealed 
> the holes in the cap with wax, and put a couple of birthday candles inside 
> to burn up the oxygen. Lit the candles and threaded on the jar.
>
> I know the candles did remove quite a bit of the oxygen. I could make the 
> heater very bright after they'd burned out, and when I unthreaded the jar 
> and let air in, the heater would burn out. I hooked up a voltage-doubler 
> supply built from a TV power transformer, so I had about 1700 V. I only 
> had a Simpson 260, but I could see current flow, that I couldn't duplicate 
> by running the heater at its maximum brilliance just short of burning out, 
> when the jar was removed.
>
> Of course, I had about 100 lb of tubes in those days, and if I'd been 
> smart I would have been making transistors. That had to wait until I went 
> to work at IBM's East Fishkill, NY, foundy in 1970. :)
>
> 73,
>
> Jim, KR1S
> http://kr1s.kearman.com/
>
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