Re: Vacume tube TC

On Sun, 8 Dec 1996 12:25:19 -0700 Tesla List <tesla-at-poodle.pupman-dot-com>
>>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 
>using a pair of 811a's (triodes) and was able to produce a nice 3" 
>discharge off the top of the coil ( tall thin candlestick variety).  I 
>switched to a 4-500z with the intent to produce greater output....
>Unfortuneately, the same circuit doesn't produce *any* brush output, 
>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 
>controll grid in the 4-500z is causing the problem and that what I 
>need is a 3-500z triode.
>Does anyone have any ideas or suggestion about this?

  Tie the two grids together, this will simulate a 
high-mu triode, which is what a 3-400 or 3-500 is.

 If a 4-400 or 4-500 is used as a tetrode without screen
voltage, the amplification factor will be very low.

			Mark Graalman TCBA#1399