Original poster: "resonance" <resonance@xxxxxxxxxxxx>Most copper ground rods are 6 feet long which means the lower 30 inches is usually in soil that has some moisture and, especially in a mild winter like we have had the past 4-5 years, the lowest 30 inches of the copper rod lie in unfrozen soil.
When driving a new ground rod try this: drive the rod in approx 30 inches, then wiggle it and remove it leaving the hole. Pour approx 4-5 tablespoons of salt into the hole, add approx 1/4 cup of water, and then redrive the ground rod all the way in. The sodium ions will slowly migrate outward and help to produce a larger ground area "field" that helps the electic RF currents link up with the moist, conductive earth. We usually spec this for science museums and ask them to drive two ground rods approx 15-20 feet apart and then interconnect them with a 2 AWG fine stranded copper welding cable. A single 2 AWG welding cable goes directly inside the museum wall using the shortest possible path to the Tesla transformer. This provides an excellent ground for the RF currents and helps minimize interference while maximizing the coils performance. We spec the connection is covered liberally with grease to help prevent corrosion and oxidation of the copper rod connection.
A great ground can usually improve a medium size coils performance with 4-6 inch more spark than a poor ground or an electrical ground through the conduit.
Dr. Resonance
Beware the Frozen Ground. If an outdoor 'ground' be used, once the dirt at the ground level freezes the ground gets worse. Documented in notes here, past. Also well documented in professional (power line, RF) ground studies. Most significant on 'hi power coils', typically. Sometimes goes away after 'some' operation, as the current melts the ice. If dirt 'ground' be deep enough: not an issue. Physics: Once the water is no longer liquid, the ions that allow current flow are trapped, more or less immobile. If natural warming, or warming from current from coil melts water around 'ground electrode', thing simprove.