Radio W4KAZ

Thanks for stopping by the virtual KazShack. Feel free to comment - I often approve them.

Empirical Evidence On Longevity Of Bare AL Radials

Finishing up on the yearly mess of litter generated by the biological antenna supports was much more painful this year[literally]. The wet weather makes dragging large quantities of sopping wet leaves a real chore. Messy too. Using a leaf blower here is equivalet to bailing the Titanic with a teaspoon. Futile. The massive quantity ofvegetative miscreants combined with a gentle uphill slope renders the leaf blower useful only for clearing small areas. Maybe a chainsaw…..

During the process, two of the radials on the K9AY were “discovered” to be broken. [Ooops!] The radials were simple 17 ga. AL electric fence wire, purchased for a pittance in 1/4 mile quantities from the local farm supply. These radials were in direct contact with the soil. Soil testing a few years back showed the PH to be about 5, slightly acidic. No real idea of the chemical/mineral content, which I expectis probably a bigger factor than the acidity.

These radials have been in place for about four years. I broke both of them while raking leaves. A closer examination showed that the portions of the wire in direct contact had become quite brittle. It took little pressure to break them this year, although they withstood similar abuse over the past three seasons. A closer look showed the aluminum to be getting flaky in spots, and it had zero ductility. Even an easy bend was enough to break the wire in those areas of heavy oxidation.

Not too shocking a discovery, but worth documenting. Aluminum radials are good for about three or four years on the soil surface – in this yard.

Conversely, the three year old elevated radials on the inverted-L were inspected just before the 2009 ARRL 160m contest. These seemed to be in fine shape, with no visible signs of oxidation and no new breaks despite catching a few falling branches over the past year.

Sothe K9AY radials will be replaced with chunks of the equally cheap WD-1A surplus “field wire”. May as well see how long that lasts too.

Leave a Reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>