Quoting Ed Sonderman:

 ES> You said you have seen in excess of 60 amps in the RF ground 
 ES> line at the bottom of your coil - when measuring for tuning.

Well not really tuning, I was attempting to measure coil
efficiency. I was at high power in perfect tune.

 ES> I know there must be a lot of current to pump the ground up  
 ES> like it does but how does a 22 guage wire carry 60 amps?

22 guage wire really can't; which is why I terminate the 22 guage
wire directly at the bottom turn of the secondary winding by
soldering it to a 3/4 inch wide by 2 inch long strip of copper
sheet. The copper strip is glued with epoxy to the coil form
directly beneath the secondary winding, and a heavy piece of
ground strap makes the connection to system ground. The ground
strap is held in place with a few strips of electrical tape or a
heavy rubber band for quick easy connects and disconnects.

The idea is that the coil does not see any 22 gauge wire in the
ground path. The maximum current is produced right there at the
coil base, and the heavy ground strap leading directly to a heavy
ground provides a low impedance path that can handle the current.

If you have sections of high impedance wiring in the ground path
(like a few inches of #22 guage wire at the base) you have choked
down your current flow, and also reduced your performance. At
power, the coil will push past this some, and RF leakage across
the floor or whatever may result.

This is yet another reason why I harp, and harp, and harp, about
heavy, dedicated, low impedance grounds and ground paths. This
thinking starts directly at the bottom turn of the secondary. 

Richard Quick

... If all else fails... Throw another megavolt across it!

... If all else fails... Throw another megavolt across it!
___ Blue Wave/QWK v2.12