Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>
I agree that a counterpoise would benefit by a connection through an RF
choke to safety ground, to establish a path for fault currents.
I have two separate RF grounds that I connect together when running my
coil. In the front of my garage is a simple 8 foot copper clad ground
rod, with 6 inches above the ground.
About 10 feet away from that ground rod, on the side of the garage, we
had an addition built, so I buried a horizontal 8-foot length of 3/4"
copper pipe on top of the concrete foundation footing, about 5 feet
deep, with a vertical 3/4" copper pipe up to the surface, in contact
with the foundation wall.
Our breaker panel is grounded to the water pipe entering the house, plus
an independent ground rod.
If I try to read the resistance between either of my buried RF grounds
to the mains ground, I get a reading of over 4 Meg Ohms. If I try to
read the resistance between the two RF grounds (about 10 feet apart), my
DMM reads open circuit! I live in Eastern Massachusetts, and the soil
about my house is rocky fill and well drained, but by no means a desert.
It's not at all clear what benefit such a high impedance connection has
to 60 Hz concerns.
I think my RF grounds are fairly reasonably constructed by most
standards, but I have no faith that they would safely ground a fault
condition. So this brings me to my point (thank you for reading so
far!) - How to construct an RF choke between the RF and green-wire
grounds that can support a fault current and still isolate RF from the
mains ground?