Tue, 02 May 2000 07:24:25 -0400
Peter Dodd wrote:
> Yesterday, Monday, I operated from GB2CPM, not on LF but at the HF
> permanent amateur station that forms part of the radio section of the museum.
> At the Electricity Hall a group of Telso Coil builders had converged
> for a Telsa coil session. This comprised two groups, an indoor
> exibition using small coils ranging from 10cm long to 1m long; and
> the second group with the big coils (up to 2m long) which had to be
> done outside because of the very high voltages they produced.
> The indoor goup had the advantage having a large room that could be
> darkened allowing the spectacular display to bee seen to its best
> advantage. The room had to be ventilated between sessions to clear
> out all the ozone!
> The outdoor group set up a test area in the afternoon, starting by
> digging a cruciform shaped trench and laying down a lot of copper
> tubing and soaking it in brine before filling it in. The components
> of three large coils arrived in special vans and I was able to watch
> and photograph these coils and the electrical control and power
> systems being assembled.
> The length of the main coils of the larger Telsa machines ranged from
> 1 to 2m with a length/diameter ratio of around 3:1. The inductance of
> the main coils ranged from 400mH to 1.2H depending on the size of the
> machine. All coils seemed to be close wound with 1mm enamelled copper
> wire. The primary coils were made of 10mm copper tubing with clip
> connections for 'tuning'.
> This main set of experiments had to be done after the museum had
> closed to the public and when it was getting dark. The corona
> discharge from 1meV machine was truely spectacular and made our hair
> stand on end!
> I was much taken with the technology of these machines, particularly
> the care with which the coils had been wound and the construction of
> high capacity high voltage capacitors. Some members of the group were
> interested in our activities in a similar technology.
> If you want to know more about the Telsa Builders activities see
> Regards, Peter, G3LDO