Re: The death of a classic

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

HI Barry,

On 16 Aug 2002, at 12:40, Tesla list wrote:

> Original poster: "B2 by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<bensonbd-at-boo-dot-net>
> 
> Hi Malcolm:
> > "What are the values of the surrounding resistors? 
> > How did a pulsed application kill the MOX reistors Barry mentions?
> > 
> > Regards,
> > malcolm"
> 
>     The MOX resistors that I used in a 300 KV Marx had the conducting
> material laid down in a back-and-forth pattern, resembling switchbacks on a
> mountain road.  Arcing (tracking) occured between the switchbacks.  The
> arcing blew the coating off between the switchbacks.  Since then, I have
> only used carbon composition or carbon film resistors in pulse work.  The
> ceramic resistors with the conducting material laid down in a helical
> pattern will work, but I now treat them as iffy and too expensive.
> 
> Cheers,
> Barry

I realized after sending my query that the Philips resistors are in 
fact metal film, not MOX.

Regards,
malcolm