Dan Richardson wrote:

Jay,

We just replace them more frequently than dry desert dwellers. After
about five years (sometime sooner) they are about shot.

My two-meter omni is incased in a fiberglass radome and my wire
antennas are made with insulated wire with ends sealed.

How close to the ocean are you? It sounds like you are right in the spray!


- Mike KB3EIA -

On Sun, 10 Apr 2005 23:58:12 -0400, Mike Coslo
wrote:


How close to the ocean are you? It sounds like you are right in the spray!


About a half mile. I live in the northern California "Mendocino"
coast. We have a lot of rain too and that combination is a killer for
aluminum exposed to the elements.

Danny

The (inappropriately named) Pacific coast where Danny lives has
fair-sized waves almost constantly, particularly in the winter. When
they break along the shore, a very fine mist of salt water droplets is
created, and those drift for a long distance. In the winter, the
prevailing wind direction is from the west, so the salt water mist is
blown farther yet. The result is that the air itself contains a
suspension of salt water. Aluminum corrodes fairly quickly, and good
sized bare copper wire turns into a blue powder in a year or less. Where
I live, in the Willamette valley of Oregon which is about 70 miles
inland, it rains pretty constantly from about October through June --
not an extraordinary amount, but everything outside stays wet for the
whole winter because of the lack of direct sunshine and the frequent
rain. But aluminum lasts forever and so does copper, which only gets a
thin, dark oxide coating. It's the salt water suspension that's the
killer on the coast.

Roy Lewallen, W7EL

Dan Richardson wrote:
On Sun, 10 Apr 2005 23:58:12 -0400, Mike Coslo
wrote:



How close to the ocean are you? It sounds like you are right in the spray!



About a half mile. I live in the northern California "Mendocino"
coast. We have a lot of rain too and that combination is a killer for
aluminum exposed to the elements.

Danny

On Mon, 11 Apr 2005 10:48:54 -0700, Roy Lewallen
wrote:

It's the salt water suspension that's the
killer on the coast.

Yea, but those launch angles to the west. G

Danny, K6MHE

Once long ago I was driving down highway 101 in my VW squareback,
operating mobile CW late at night on 40 meters. Rig was homebrew, about
8-9 watts output (10 watts input). Antenna was a CB mobile whip on a
bumper mount, base loaded with a coil wound on a powdered iron toroid
core, Q about 200 - 250. Worked JA, solid copy. Yea, that salt water
does wonders for a vertical.

Roy Lewallen, W7EL

Dan Richardson wrote:
On Mon, 11 Apr 2005 10:48:54 -0700, Roy Lewallen
wrote:


It's the salt water suspension that's the
killer on the coast.


Yea, but those launch angles to the west. G

Danny, K6MHE

On Mon, 11 Apr 2005 06:47:14 -0700, Dan Richardson
wrote:
On Sun, 10 Apr 2005 23:58:12 -0400, Mike Coslo
wrote:

How close to the ocean are you? It sounds like you are right in the spray!

About a half mile. I live in the northern California "Mendocino"
coast. We have a lot of rain too and that combination is a killer for
aluminum exposed to the elements.

Has anyone done any testing (RF resistance) on squirting some NOALOX
compound (or other anti-corrosion sealants) between the aluminum
elements and scrubbing them clean to remove the oxide film before
bolting them together? Should help a lot, especially along the coast.

Works great on AL power wire at 60Hz...

-- Bruce --

(KBPY-8540 - wait, they discontinued those calls. Oh well...) ;-)
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.

The problem with aluminum at the coast isn't an oxide that has to be
removed. It's just the opposite -- the problem is that salt water
removes the oxide that needs to be kept intact. Aluminum is a very
active metal, which oxidizes almost immediately on exposure to air. The
oxide is a hard, non-porous ceramic which, after forming a very thin
layer, prevents any further contact of the aluminum with air. The
problem is that aluminum oxide is slightly soluble in salt water and
other acids. So the oxide coating is removed by the salt water, exposing
more aluminum to salt water and air, allowing it to corrode. It does
help to coat metals with grease, but only because it prevents the salt
water from contacting the metal or, in the case of aluminum, the oxide
coating. But the last thing you want to do is intentionally remove the
oxide coating.

Roy Lewallen, W7EL

Bruce L. Bergman wrote:

Has anyone done any testing (RF resistance) on squirting some NOALOX
compound (or other anti-corrosion sealants) between the aluminum
elements and scrubbing them clean to remove the oxide film before
bolting them together? Should help a lot, especially along the coast.

Works great on AL power wire at 60Hz...

-- Bruce --

(KBPY-8540 - wait, they discontinued those calls. Oh well...) ;-)