Re: Vacume tube TC

Tesla List wrote:
> >From DavidF4797-at-aol-dot-com Sun Dec  8 12:00:28 1996
> Date: Sun, 8 Dec 1996 09:46:18 -0500
> From: DavidF4797-at-aol-dot-com
> To: tesla-at-pupman-dot-com
> Subject: Vacume tube TC
> I've been tinkering around with a vaccume tube coil now for several months
> using a pair of 811a's (triodes) and was able to produce a nice 3" brush
> discharge off the top of the coil ( tall thin candlestick variety).  I then
> switched to a 4-500z with the intent to produce greater output....
> Unfortuneately, the same circuit doesn't produce *any* brush output, although
> if I get a flourescent tube near to the primary and secondary it lights up so
> there must be output of a sort.  I have heard it speculated that the extra
> controll grid in the 4-500z is causing the problem and that what I really
> need is a 3-500z triode.
> Does anyone have any ideas or suggestion about this?

If memory serves, you connect the control grid to the feedback
winding and bias the screen grid. Anyone else on the ball with
tube stuff?

- Brent