RE: More facts: Coil size to faraday cage size ratio

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Steve Conner" <steve.conner@xxxxxxxxxxx>

>So, maybe something to kill the HF content in the primary circuit

The coil Finn is working on is an OLTC. It should be far less electrically
noisy than a spark gap coil. If the primary current did have too much HF
content (unlikely as the large IGBT is fairly slow switching) then it could
be reduced to any desired level by adding resistance to the gate circuit to
slow the switching even more.

I still think that the noise is being generated when streamers strike the
inside of the cage. It's well known that an arc between two metal objects
produces lots of high frequency RF, since the metal objects and arc channel
together resonate as a half-wave dipole with capacitive loading on the ends.

The first radio transmitters by Hertz, Bose, et al. worked just this way and
gave output in the UHF to microwave region with arcs a few cm long between
metal spheres.


Steve C.