Good answer, Greg. DC is certainly not the best way to measure an RF ground.
I wonder what the difference would be if we used 1.8 MHz instead of 100 Hz? I thoroughly soak the earth around the rods here with Epsom salt (magnesium sulfate). It *really* decreases the ground resistance! The difference between a newly-driven-in rod, and after applying that treatment, is immediately obvious by listening to the receiver. Of course, as N3OX once quipped, "I'm fond of adding elemental copper in thin filaments stretching radially away from the ground rod for some distance". ;-) 73 Mike www.w0btu.com On Nov 15, 2016 10:16 AM, "Greg - ZL3IX" <zl...@inet.net.nz> wrote: > I came across this problem when I first started using Beverages in 2008. I have come to the conclusion that the DC resistance measurement is corrupted by electrochemical effects between the grounds, ie potential differences. I then changed to an AC measurement. I made a simple 100-or-so Hz oscillator using an op amp and I put this between the two wires in parallel at the feed and the ground. There is a 100 ohm resistor in series. I measure the AC voltage across the Bev and the voltage across the resistor and thus deduce a loop resistance through the ground. _________________ Topband Reflector Archives - http://www.contesting.com/_topband