Re: rf ground?

[Terry Fritz <twftesla-at-uswest-dot-net>]

Hi John,

At 06:24 AM 7/18/00 -0500, you wrote:
>
>Hey everyone,
>
>I sent this msg out last Friday but never received any answers so I'm trying
>one more time.
>
>

Thanks for asking again.  Sometimes when a lot is going on we don't get to
every ones questions...

>
>Hey folks,
>
>I havent done any coiling in 10+ years.  Back then the largest system i had
>was powered by a 15/60 NST.  At the time i just ran a long piece (15') of
>#18 stranded wire from the base of the secondary with the other end clamped
>to any electrical conduit I could find.  It seemed to work fine.  I have
>been reading some posts in the archives about the secondary being a
>different ground.  An rf ground.  My question is this, was what i did a
>BADDDD thing?  Also, had i driven multiple pipes into the ground and
>interconnected them and used them as my secondary ground would i expect to
>get any improvement in discharge length?

I use two grounds.  The first is a pure 60 HZ AC line type safety ground
that is designed to take short circuits and other typical AC line faults.
The switches, variacs, and control equipment all rely on this ground for
electrical safety.  Rarely is the AC line ground able to take high current
RF pulses since house wiring simply is not designed for this.

The second ground is the secondary RF ground.  The base of the secondary
coil and anything the streamer can hit is grounded to this.  The RF ground
should be short and thick to handle the ~15 amp ~250kHz RF from the coil's
secondary.  Ideally, this ground should also be able to take AC line faults
too.

So everything "I" touch is grounded to the AC wiring ground and everything
the streamer can hit is grounded to the RF ground.  This works well for me
and keeps the RF from getting into the house wiring were it can do bad
things to other stuff in the house.

Cheers,

	Terry


>
>
>Thanks again,
>John M.
>