Topband: One wavelength Beverage

[Tom Rauch]

Hi Jerry,

> Actually you should use insulated wire because bare wire is more
susceptible
> to extra noise from rain and snow static.

There is a myth that claims charged moisture droplets hitting the antenna
are responsible for precipitation static. I've actually dome experiments to
try to prove that, and have never been able to create or verify that effect.

All my initial Beverages were insulated wire, now all of mine are bare wire.
There was never any difference between them under any condition.

Precipitation static is caused by corona discharges from pointed high
objects, where high charge gradients tend to leak off during inclement
weather.

People with stacked Yagi's will testify that the upper antennas are almost
useless during bad weather, while lower antennas are often dead quiet. This
is despite the fact that the upper and lower antennas are being struck by
the same moisture. My own antennas behave that way, so do VHF repeater
antennas. Fiberglass antennas like Stationmasters are just as noisy as
exposed bare dipoles, and unless the antenna is sidemounted down from the
tower top "precipitation" noise is a problem.

Another way you can tell is by listen during a lightning strike. The
sizzling and rushing noise will build up to a very strong level, then "pop"
a distant lightning hit makes it all immediately stop. If was charged drops
hitting the antenna, there would either be a delay in noise abatement or no
change at all.

There is a way insulation can help, and that is if the insulation covers
sharp points. Other than that, it's folklore.

73 Tom