>> Does anyone have any ideas of how I can solve this
> There is some controversy or difference of opinion on this,
> but my experience, everything I can measure or simulate, and
> any data I get from other sources indicates the noise is
> from corona discharge from sharp points in or around the
> antenna. This corona discharge is caused by voltage gradient
> between the earth and clouds around the antenna during
> inclement weather.
> The other opinion (that I do not find evidence to support)
> is that charged droplets or particles hit the antenna and
> discharge, making noise.
I think you will find that precipitation static is neither.
It's basically the a charge building from many droplets, or snow flakes
removing electrons from the ungrounded elements, or wires. The charge
builds to the point where it arcs over.
Snow is particularly bad with this and the stronger the wind the more rapid
I've never had precipitation static from a grounded antenna.
> Regardless of the actual effect behind the noise grounding
> the antenna or the fact it is a log periodic has nothing to
> do with causing the problem or with sensitivity of the
> antenna to noise. I have that problem with gamma matched
> yagis just as much as with insulated elements. It occurs
> with dc grounded elements the same as with floating
That has not been my experience. However if there is an ungrounded antenna
near by, closeline, guy lines, or electric fence they will generate a spark
just like the old ignition systems with solid wires. Those things could be
heard for hundreds of yards.
> We spent weeks working on repeater and other communications
> systems on tall buildings trying to eliminate that type of
> noise. Lowering the antenna, making protruding antenna ends
> blunter or more rounded or using insulated element tips,
> installing something higher above the antenna to divert
> charge to that other point and away from the antenna
> elements, and eliminating sharp points on the tower and
> antenna often help.
The worst antenna I ever had for precipitation static was a 1/4 wave, ground
mounted vertical on 40 made out of 1 1/2" steel masting. On a windy day
when it was snowing that thing would develop an arc across the end of a
PL-259. It wasn't straight across either. The arc would extend as much as a
half to three quarters of an ench forward from the tip of the connector and
it'd pop like a small firecracker. It was a nice *thick* bright blue arc
about every 5 to 10 seconds.
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
> When I have that noise here I switch to a lower antenna.
> 73 Tom
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
> Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> any questions and ask for Sherman, W2FLA.
> TowerTalk mailing list
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
TowerTalk mailing list