Re: rotary gaps

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Finn Hammer by way of Terry Fritz <twftesla-at-uswest-dot-net>" <f-hammer-at-post5.tele.dk>

Hi Bob!

Set the electrodes as close as you dare!

Depending on the general stability of the completed setup, you want to
have some clearance btwn. electrodes to avoid collision,(sp) crashing
the electrodes together. This generally tends to at least destroy the
electrodes.

But you also want the gap to start conducting at a low voltage, low
enough to enable tuning of the coil at low power.

I have found with my quadruble MOT powered coil, the RAT, which peaks at
around 11 kV (much like your radar transformer), that if I set the
electrodes 1/2 mm (20 thou) apart, then the coil starts to make
discharges from a breakout point at a comfortably low variac setting.

With the Museum coil, which peaks the cap to more than 30 kV, it is fine
to have the electrodes 1 mm (40 thou) apart.

Hope this helps some.

Cheers, Finn Hammer

Tesla list wrote:
> 
> Original poster: "bob golding by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <yubba-at-clara-dot-net>
> 
> Hi all,
>     I have almost finished my rotary gap and am at the stage of
> adjusting the gap spacing. Anyone suggest a good starting point for the
> gap. I am running a 8 kv 250 ma radar transformer with up to 97 nF of
> cap into a 10" x 42" secondary. It is drawing around 12 amps from my 240
> volt supply. The electrodes are 4.8mm tungsten. I am using 4 flying
> electrodes and 4 static.
> 
> cheers
> bob golding