Random ground measurements
On Sun, 17 Jun 2007 10:35:06 -0700, Tim Shoppa
wrote:
I kinda wonder why I spent money on all this heavy 6 AWG copper wire
to hook everything together, when the resistance of the ground itself
is bigger than the resistance of the wire. I mean, it wouldn't feel
right wiring it with 22 gauge hookup wire, but isn't 6 AWG overkill?
10 Ohms of 6AWG is like 5 miles of copper that I can't afford :-(.
Hi Tim,
The choice of 6 AWG, I suppose, was driven (or should have been
driven) by code.
The alternative to your 10 Ohms would be infinite Ohms. In that
sense, quite an improvement. Driving it down to 1 Ohm will take much
more effort (and grief).
Yet and all, it has nothing to do with RF ground (sorry). What you
have accomplished serves your safety from lighting strokes. On the
plus side (when we get beyond survival techniques) you also gain from
removing a lot of ground currents getting into your gear. This can be
especially painful in the sense of Signal to Noise ratio. Worse, if
untreated, it can lead to component failure or shock hazards (you DID
connect all these grounds together, didn't you?).
Laying radials would have reduced your ground resistance, faster, and
lower - but this is not conventional code. Radials will help with
near RF ground, but will not otherwise help with obtaining those low
DX launch angles (not, unless you invest in 5 mile radials).
The discussion of the benefits/pay-back for radials drives a lot of
discussion. Simple advice (if you are building a vertical) is to make
them as long as your antenna is high, and plant a dozen or two about
an inch below the soil, or beneath the grass above the soil.
73's
Richard Clark, KB7QHC
|