Re: BIG counterpoise

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

Original poster: "Mark Broker by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mbroker-at-thegeekgroup-dot-org>

I have a similar grounding issue.  The coil I built and left my physics 
department has gone
through 2 transformers, with properly set safety gaps and 
TerryFilter.  (Ok, so the ground
wasn't attached to the TerryFilter the last time.)  The coil is 6" 
secondary with 15/90 input,
SRSG, LTR MMC (Panasonics - long before the GeekMMC).  It is run almost 
exclusively
on the third floor of the physics department on the inner "square" of the 
building
(surrounded by classrooms, offices, or a hallway).  I've used mainly a cold 
water pipe for
RF ground, which seems to work, though I have no clue if the pipe is metal 
all the way to
the ground.  I've also used a big flexible steel conduit that was housed 
the lab power supply
feeds from the monster regulated power supply in one of the back 
rooms.  There was no
performance difference between the two.

Running a long dedicated ground out a window isn't an option for a variety 
of reasons.  The
best option is a counterpoise.  But I'm concerned that the concrete floor 
40 feet above soil
will be a good enough reference point to keep the counterpoise voltage 
sufficiently low.  I'd
hate to lose another transformer or even the spark gap motor due to 
excessive ground
potential....

Mark Broker
Chief Engineer, The Geek Group