K5RC sez:
> Is rain and snow static the result of ionized particles discharging
> against
> the antenna or is it just an ionized field passing in close proximitiy
> to the
> antenna? I've heard both theories offered. If the truth is the later,
> then
> insulated wire will not make any difference.
>
And then there is wind-induced static. Those who are familiar with ESD
(electro-static discharge) may also be aware of the Triboelectric
Series. This is a list of many substances and is arranged according to
the tendency of each substance to either lose electrons or gain
electrons due to friction; another way to explain it would be that they
are arranged in order of their capability to hold an increasingly
positive or negative charge. The further away from eachother any two
substances are on the list, the greater the potential charge that may be
built up when those two substances rub against eachother. Human hands
and air are at one end of the chart, and teflon, silicon,
polyvinylchloride, polypropylene, polyethylene are at the other end of
the list. So, for instance, bare hands stripping teflon inulation from
wires can create a huge amount of static electricity. By the same
token, wind blowing on insulated wire will generate more static than
wind blowing on copper wire (copper is closer to the center of the
chart).
If the insulation is charged by the wind, the wire will become similarly
charged since it is in the charge field. I am only going on theory
here, not experience, but it would appear that insulated antenna wire
will become more charged by wind than non-insulated wire, FWIW.
73 / HNY!
Dave WD5N < DavidHarper@tx.slr.com >
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search
|