RE: VTTC provisional results

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

Original poster: "Herwig Roscher by way of Terry Fritz <twftesla-at-uswest-dot-net>" <herwig.roscher-at-gmx.de>


James wrote:

> The arc would smoke the primary and short it (large carbon
> track).

James,

Sorry to read that you faced the same problem.

> I rewound the primary as a funnel. It will be a pain to do 65 turns. 
- Before taking this trouble I would like to make an other approach: 
I am planning on substituting the PVC insulated house wire by 
magnet wire of the same copper cross section. This would half the 
height of the coil and reduce the voltage difference between the 
uppermost turn of the primary coil and the secondary coil (as the 
voltage of the latter increases with height).

As I suspect that the sharp edge of the flush screw, I used to fix 
the wire, contributed to the effect, I shall try to find a better 
solution. How did you solve this problem?

As PP has got a smaller dielectric factor than PVC it should create 
smaller rf surface currents which are the reason for these carbon 
tracks and flashovers IMO. Unfortunately I could not find a 8" PP or 
PE form (should have thin walls!) up to now.

Regards,

Herwig