Re: A new tuning idea?

["Mark Broker" <broker-at-uwplatt.edu> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Steve and list,

While tuning my own coil, I used a friend's clamp-on anolog AC ammeter that
operates the same way as is described below.  These can be purchased at
hardware
stores for very little money.  I believe I ran across one at a True Value for
about $40-50.  And it's good from 6 to 300A (the max settings).

While running the coil, I clamped it over the ground cable, and was unable to
get a reading.  I may have had it set too high, but the needle should have
jumped a little even on 30A (or whatever the setting was).  When I had
attempted
this, I was running two of my three 15/30's with an LTR cap (~28nF) and SRSG.
It was not in great tune, but was kicking off some decent 3 foot streamers.

I never did try to get a measurement after I got it in better tune with the
third NST and 42 nF cap - I was too busy watching the purdy blue 5' sparks :-)
I'll probably try the next time I fire it up (which won't be soon, as it's on
the other side of the state :-(  )

Mark B.



> How about this as an alternative, it's used by radio hams for monitoring
> earth current. Feed the lead through a ferrite ring. Wind a number of turns
> of thin wire through the core to form a secondary. Connect a lowish value
> resistor across this, and then measure the induced voltage using an analogue
> ac voltmeter. I can't remember any values, but in any case it would depend a
> lot on your particular coil. i only give this as an idea that might be worth
> playing with, come to that I might have a go myself over the next few days.
> Steve