[TowerTalk] Power ground

[Tom Rauch]

Interesting that "silver solder" is rated to a higher temp
than compression fittings. >>

Who cares anyway? Lightning isn't a long pulse, so unless
you have an actual arc the heating is minimal in any good
connection with wide surface area. It is small contact area
pressure connections that are the problem with heating.

Failures are typically in areas like we find when arc
welding. The heat is all in high resistance areas and
hundreds or thousands of times worse at an arc area. I have
holes burned completely through the top strike area of a DB
Products 150-MHz metal dipole array at my tower top, and the
steel bracket and clamp areas are perfect despite the lack
of cadweld or other "superconnections".

Everyone should follow codes, but from a practical
experience standpoint I've never in my life seen a good
silver-solder connection fail. My radials, which essentially
are all that grounds my towers, are #16 wire. They are
soldered to a copper flashing. My tall tower (318ft with a
20ft VHF antenna on top) gets whacked several times a year.

At BC stations, we would braze and silver solder and did so
for years and years and I never once saw a connection fail.
Cad weld was unheard of, just like all these lightning
suppressors. The damage then wasn't any different than it is
now with all the new expensive devices. I don't have a
single polyphasor anywhere and even the GAsFET preamp
remains undamaged hit after hit.

99.9% of protection is from common grounds and common sense.
I've seen people cadweld and polyphase the heck out of
installations and attach guy lines right to the house, or
bring cables off a tower ten feet up and straight into a
house with no common to the power line. Almost silly when
you think of it. The cheap important stuff is neglected
while the .1% expensive stuff is attended to.

We'd be better off telling people how to avoid the serious
mistakes.

73 Tom