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Re: VTTC



Start with a height to dia ratio of 11:1 or 12:1.    A 2-3 inch dia tube
works well.  Use around 40 turns on the primary so you can tap between 15
and 40 turns at any point.  You usually end up with 18-25 turns for best
performance.  Use a very small gauge wire like #30 or #32 if your power
level is under 1 kw.  Use a 200 degree C magnet wire with heavy armor
insulation like Beldon Polythermalize.

Tube circuits like a lot of primary inductance to get the impedance match.
Use a very small 1/4 inch brass ball on top or a needle.   Sometimes a ball
with a needle sticking out of it works good too.  Experiment with this.

Coeff. of coupling should be very tight --- most primaries are wound
solenoid style on a large 6-8 inch dia PVC tube.

Dr. Resonance


-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Monday, February 21, 2000 9:02 PM
Subject: VTTC


>Original Poster: "Herwig Roscher" <herwig.roscher-at-gmx.de>
>
>
>Hello,
>
>I'm planning on building a DC driven, CW operated VTTC. In
>contrast to spark gap excited systems, both, the primary and the
>secondary circuit, are parallel resonant circuits here. Therefore I'm
>assuming that the L/C ratio of the primary coil should be different
>from the "standard design". The turns ratio primary coil/secondary
>coil and the coupling factor between these coils are responsible for
>suiting the plate resistance to the discharges.
>
>Up to now the planned system looks like this:
>Primary circuit: C = 2 nF, form = 6", turns = 25, AWG = 12
>Secondary circuit: Form = 3", turns = 900, AWG = 28, corona
>shield, some " apart
>Grid coil: Form = 6", turns = 12, AWG = 22, distance from primary
>coil about 1"
>
>Does this sound good?
>
>Q: Terry found out, that the streamer load for disruptive systems is
>equal to 220 kOhms in series with about 2 pF per foot of streamer
>length. Does anyone know similar figures for the "brush" of CW
>systems?
>
>Q: Are there any figures for the number of primary turns, the L/C
>ratio and the coupling to get me in the ballpark (in case, the a. m.
>concept is totally wrong)?
>
>I know, there's a long way to go and would appreciate some help.
>
>Regards Herwig
>
>
>