Ed wrote:
A new commercial radio hilltop vault is being installed in my area....
and the contractor has installed the tower and vault ground ring with
aluminum wire/cable, I have been advised. I do NOT know the gauge of
the wire, but I am curious what your thoughts are on this issue. I have
been involved the past 35 years of my career in a number of ground
installations and every one of those used large copper cable... no
aluminum anywhere. The last of these I saw was 6 or 7 years ago.

QUESTION: Are aluminum ground systems becoming common? Are they
reliable, even after absorbing some heavy strikes? Any other comments?

Ed K7AAT on the Oregon Coast

My only experience with an aluminum wire ground system was one I laid
many years ago in Denver, with buried aluminum radials. It was pretty
badly corroded in a few years. But the soil there is alkali, not like
the acid soil you have on the coast. Interestingly, aluminum corrosion
is minimum at a pH of about 5.5 (see
http://www.tpub.com/content/doe/h101...015v1_121.htm), which is
likely roughly what your soil is. So while there might be a lot of
places where corrosion would be a problem your location might be one of
those where it wouldn't.

Roy Lewallen, W7EL