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Re: coil setup



Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> 

Hi Richard,

If I understand what you are saying here, I think you got it correct given
the following assumption:

The NST is located underneath or just next to the TC coil in an area
considered unsafe because of exposed TC primary and streamer reach,  then I
would connect the NST chassis, strike rail, and bottom secondary to the RF
ground.  The RF ground should have a good connection to a well staked rod in
the ground.  The Terry filter center ground should be directly connected to
the NST chassis for best protection of the NST.

The following describes the basic charging connections without mention of
the Terry filter for simplicity.  The Terry filter of course in inserted
between the NST bushings and the TC primary/sparkgap circuit.

If the NST has a two bushing output (a center tapped secondary),  both will
be used for charging the primary circuit and the primary coil will NOT be
grounded.   One bushing (A) will drive Cp in series with the TC primary coil
and the other side of the TC primary coil will be connected to the other
bushing (B).  The spark gap will then be from the Cp/bushing (A) node  to
the other side of the TC primary/bushing (B) node and be physically close
the the TC primary because of the high current path the spark gap is part
of.

Only for the case of a one bushing NST (where one side of the NST secondary
is grounded to chassis), will the TC primary be grounded.  This bushing will
drive the charging (Cp in series with the TC primary coil) and the other
side of the TC primary coil will be grounded to RF ground (as well as the
NST chassis).

The line ground should NOT be connected to the NST, given the above
assumption, but should be connected to the line filter and variac (items
located in the operators vicinity).

Gerry R.


 > Original poster: "Richard Modistach" <hambone-at-dodo-dot-com.au>
 >
 > i was going to connect the bottom of the
 > secondary to the strike rail and to the center
 > of the terry filter and to the center tap\case of
 > the nst to a ground rod, not planning on
 > connecting to the primary.
 > i thought i did my homework,
 > does this sound right ?
 >
 > regards
 > richard
 > aus
 >