Re: async rotory gap?

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

Original poster: "Metlicka Marc by way of Terry Fritz <twftesla-at-uswest-dot-net>" <mystuffs-at-orwell-dot-net>

duncan,
(sniped)

Tesla list wrote:
> 
> Original poster: "Dr. Duncan Cadd by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <dunckx-at-freeuk-dot-com>
> 
> Hi Bart, David, All!
> 

are the disks notched at the edges to make and break the arc? if not
then how is the quench controlled?

> 
> There is one further variety, which AFAIK has not seen service since
> Marconi, but maybe there's someone out there who has done it and can
> comment, and I'm posting this in the hope they will step forth and do
> so!  It would be a particularly neat project for 2001 as it was the
> device used in the first successful transatlantic transmission a
> century ago.
> 
> The main problem which the rotary was designed to cure is quenching at
> high power, i.e. the prevention of continuous arc formation.  Whilst
> the rotaries used by most (all?) these days use fixed and flying
> electrodes, which limit the discharges to specific points on the
> timing cycle (or pseudo-random if asynch) Marconi's original idea,
> used in the Poldhu transmitter 100 years ago (the infamous
> transatlantic "S" signal) was to use two (or more) rapidly rotating
> disks spaced a short distance apart, their axes at right angles, with
> the spark taking place between the rims of the disks.
> 
marc m.