Re: Building a 3-1000z VTTC

To: tesla-at-pupman-dot-com
Subject: Re: Building a 3-1000z VTTC
From: "Jeff W. Parisse" <jparisse-at-teslacoil-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Thu, 02 Sep 1999 05:17:21 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Ross (et. al.),

> 1.  What is the largest diameter secondary that this tube can power?

Same general rules for spark coils. I'd say 10".

> 3.  The tube specs state the the filament needs 7.5V at 21.3A.  The
> filament transformer that came in the box is a 7.5V, 25A.  Is this OK or
> do I need to drop the current somehow (add series resistance?)

The tranie is OK. The filament "pulls" 21.3 A and the transformer is
able to supply 25A.
 
> 4.  Any hints on appropriate component values will be greatly
> appreciated.

Add RF bypass caps (.01uf) to ground on both filament leads.

Place the plate transformer after the filament "on" switches to prevent
turning on the plate before the filaments are warmed up.

Grid RC should go between feedback coil and tube grid (although
that way you have should work anyway).

Plate choke (LR) may be unnecessary in a Tesla Coil.

Use a variable resistor for the grid feedback RC network. Use
twice recommended wattage (for an AC system) because you're
using unfiltered DC.

Jeff