On 06/09/2018 17:22, Jeff Liebermann wrote:
On Thu, 6 Sep 2018 14:46:33 +0100, Gareth's Downstairs Computer
wrote:

Interesting because between the house TT earth, a steel rod and the
copper RF earth is now about 0.4 volts, making the ohmmeter go haywire
trying to measure the resistance between them.

That's only true if there's an electrolyte between the copper and
steel. When bonded together, there's no galvanic action or voltage.
If you're using two or more ground rods, all electrical codes specify
that they need to be connected together with some heavy gauge wire.

Separate RF earths to reduce noise on RX and protect family members from
RF hazard if touching central heating radiator 1/4 wavelength away.