Re: Tubing, how bizarre they are!

To: tesla-at-pupman-dot-com
Subject: Re: Tubing, how bizarre they are!
From: Mark S Graalman <wb8jkr-at-juno-dot-com>
Date: Wed, 12 Feb 1997 08:50:05 EST
Subscriber: wb8jkr-at-juno-dot-com Wed Feb 12 23:02:30 1997


On Tue, 11 Feb 1997 23:25:56 -0700 Tesla List <tesla-at-poodle.pupman-dot-com>
writes:
>Subscriber: dwt-at-efn-dot-org Tue Feb 11 23:06:26 1997
>Date: Tue, 11 Feb 1997 17:17:23 -0800
>From: David Trimmell <dwt-at-efn-dot-org>
>To: tesla-at-pupman-dot-com
>Subject: Tubing, how bizarre they are!
>
>Hello, I want to thank John Freau publically for sending out the tube
>coil schematic. I threw together a coil this weekend using a modified
>version of the design john provided me with, and am pleased with the
>prelimanary results. With two 803's and a microwave oven transformer I
>am able to get a wonderfully bizarre brush discharge of five inches.
>These babies are a sensitve lot though. Ok, so now for the qustions: 
>How
>hot is to hot for the 803's? I can run them for about two minutes 
>before
>they get to hot to touch, this is with a 2400 Volt -at-~500mA (actually 
>not
>sure of the current rating of the transformer, the microwave was rated
>at 1.2 Kw). Next qustion: I have  two 4cx250b's, but could trade them
>for a pair of 813's, I like seeing whats going on inside, but the
>4cx250b's have a 250 watt PD and the 813'S only a 125, should I stick
>with the 4cx250b's? Thanks for any sugestions,
>
>David Trimmell
>


   Hi David,


  You have to move ALOT of air through the 4cx250 anode
cooler to reach the 250 watt rating, and the 250 is 
nowhere near as forgiving as far a over voltage or any
kind of overload condition. The 813 is a much larger tube
but I think for a tesla coil it would be a much better
choice.

			Mark Graalman