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Re: Hot Tubes (Was "Tubin

Hello all:


> >T>am able to get a wonderfully bizarre brush discharge of five inches.
> >T>These babies are a sensitve lot though. Ok, so now for the qustions: How
> >T>hot is to hot for the 803's? I can run them for about two minutes before
> >T>they get to hot to touch, this is with a 2400 Volt -at-~500mA (actually not
> >[ ...]
> >
> >T>David Trimmell
> >
> >
> >
> >        How hot do like it, baby?  Most transmitting-class vacuum
> >        tubes can =at minimum= run all day with their plates dull red.
> >
> >        Some are designed to run with bright-orange-hot plates.
> >        The general rule seems to be: if the plates are metal, then
> >        stick with red-hot as a maximum.  If the plates are graphite,
> >        then bright-orange is okay.   They can (and should) be air-
> >        cooled (like with a fan) for max. life.   The higher power
> >        tubes fit (and require) special ventilated sockets.
> >
> >        Hey -- these aren't transistors, you know.   They date from
> >        an era when men were really men, and you could literally
> >        warm your lunch on your electronic equipment.
> >
> >                                In a fever,
> >
> >                                Robert Michaels
> 
> Your Tell 'em Robert!!!
> 
> And none are more manly than John Freau, the white plate/ white knuckle
> champ!  I have always been amused at how John uses the absolute max ratings
> on the spec sheet as a starting point for design.  Luckily John is a veteran
> hamfester and buys up tubes like popcorn. (good thing too).  The secondary
> electron emission from his 833 plates exceed that from many tube's
> cathodes!!!!  John could use radiation warning labels on his gear because of
> intense IR output from his systems.  Anyone can operate a tube on spec in a
> Tesla coil, but it takes a manly guy like John to experiment with gathering
> data on stressed tube lifetimes while also doing Tesla coil experiments.
> 
> We have captured a lot of this Freauian boldness on tape and his
> incandescent plate mode oscillators are a real hoot!  The electron density
> in the cathode/ plate space vacuum must approach that of a conductive jelly!
> The plates are the targets in these oscillating electron accelerators.
> 
> A little humor is always held in high esteem amoung us Tesla types.
> Actually John's timely admonition about not proceeding beyond dull red
> paltes is not advice from someone who hasn't vaporized a few plates and sent
> more tubes than you or I will ever own to an early grave.  Heed his words
> unless you have lotsa' toobz layin' around!
> 
> Richard Hull, TCBOR
> >
> >

Actually, with a little play'in round, I'v been able to get 4" HOT Neon
signish arks to a metal rod in my hand, and 6 to 7" stabbing arks into
the air! These babys are cool! If only metaphorically. After two and a
half hours of testing, the microwave trany was getting a bit warm, but
the plates of the Tubes never even got close to being orange. I ran them
for five minuts with the hot six inchers stabing into the ether, and the
plates still didn't show any color (yes, I'v melted sparkgaps in less
time). Thanks again to all the Tubers that helped me, these guys
definatly put out the amps!

David Trimmell