Re: 833A tube coils (fwd)

---------- Forwarded message ----------
Date: Thu, 21 May 1998 22:41:54 +0200
From: Pete <casius-at-cyberserv.co.za>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: 833A tube coils (fwd)

Hi John,

Am very pleased to make your aquaintance. Thanks very much for the info re
833A tubes in coil work. Am quite far with the construction. The filaments and
grid resistors/capacitors are wired up. The tube mounts are fixed in place
(vertical orientation). Have mounted a 0-100mA meter on the front panel. Still
have to mount the capacitors for the resonant part of the circuit.
Played with my 812AW coil last night. Have 3 of these tubes running. Optimised
the resonance. Get 500mA at 1.5kV. (+/-750 watts). The discharge was +/-160mm.
Wow it really churns up the medium wave band. The coil operates at +/-570kHz.
I will have to put in a really good earth I think.
I would really appreciate the info on getting 42" sparks from a 12/30 NST.

Thanks once again

Tesla List wrote:

> ---------- Forwarded message ----------
> Date: Wed, 20 May 1998 11:36:40 EDT
> From: FutureT <FutureT-at-aol-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: 833A tube coils (fwd)
> In a message dated 98-05-19 16:27:43 EDT, you write:
> << Hi out there,
> > I am busy busy building a tube coil using two 833A tubes. Has anyone out
> > there done this and what can I expect. Are there any special
> > considerations.
> > I also have a three tube coil using 812AW tubes. Gives me a 4"  brush.
> > I also have a 4" x 19.5" convensional coils powered by a 12/30 neon
> > transformer, gives me 12" sparks. Don't think this is optimum as yet.
> > Best wishes and happy sparking
> > Pete >>
> Pete,
> A 12/30 NST coil can give at least 42" sparks, I can send you the
> specs if you'd like (they're in the archives of this list also).  I use
> a synchronous rotary spark gap in the design.
> The 833A tube is commonly used for VTTC's.  One 833A can give
> about 23" sparks, and two can give about 31" sparks.  In one test,
> using three (?) of these tubes, I obtained about 42" sparks. The plate of
> the 833A tube will run a orange color.  For best results, quite a lot
> of plate voltage is needed, at least 4.5kVAC.  Specs for various 833A
> powered tube coils are in the archives also.
> Happy sparking to you too,
> John Freau