Re: COMMENT ON USE OF WOOD IN TC'S

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: FIFTYGUY@xxxxxxx 

In a message dated 10/3/06 6:59:37 P.M. Eastern Daylight Time, 
tesla@xxxxxxxxxx writes:

>It could be the non-monolithic surfaces

    On one hand, surface imperfections and dirt tend to cause 
tracking problems? But on the large scale, HV insulators are designed 
with ribs to increase the surface tracking distance. Why is a subtle 
intermediary surface finish advantageous with RF?

>the trapped air content of wood that gives it it's edge.

    IIRC from the discussion we had not too long ago regarding 
insulating between magnifier primaries and secondaries seemed to 
indicate that any trapped air or voids in the insulation only served 
to concentrate voltage gradients and contributed to failure from 
corona. Same reason cap makers go through pains to vacuum their 
creations. Why does trapped air help wood insulate RF?

    If these two properties of wood make it a superior material, can 
these properties be duplicated in a plastic? A very high-density 
foam, perhaps? Something possibly cheaper or easier to form bulk 
structures with?

-Phil LaBudde