Topband: water saturated ground effect MA160V

[k3bu at optimum.net]

N0AH wrote:

> Today, all test were at the feedpoint, without the UnUnm 
> including trying two different short feedlines of a few feet- 
> They both showed the same- the minimum SWR is finally creeping 
> up a bit, from 1:1 yesterday to 2.1:1 today- then it rained 
> again- I feel the ground soaked earth is causing some 
> interesting measurements on the antenna. Very unexpected. In a 
> few days, once we return to a scortched earth, it will be 
> interesting to see what happens. If the SWR goes back up to 5:1 
> or so without the UnUn in line as things dry out, that is, just 
> measured at the feed point, this would be an interesting topic 
> to discuss- If it remains low, then I'll just look at the 
> loading coil - but since it rose up some today, I really feel 
> the drying out saturated ground is messing with things- thx for 
> all the awesome responses- This is a good topband antenna for 
> small back yards from our view-

I think you are seeing improvement in ground plane conductivity situation and it's effect on antenna.

One half of the vertical is in the radials/ground.
Using fewer and shorter radials handicaps the overall performance.
Watering the ground in vicinity of antenna/radials makes that other half less lossy, improves performance. Add some salt and you got even mo' RF.

Antenna system should be seen as ANTENNA in the ENVIRONMENT for the overall performance. Ground/soil is that RF mirror that affects the performance of antenna, forming the beam pattern - angles and magnitude.

Ocean front adds 10 - 15 dB. One or two elevated radials on the beach will beat 60 radials on dry ground, adding Fresnell zone for added efficiency and lower angle. 
This is approximated by the rain soaked neighborhood, modulated by the soil conductivity.

I used to fertilize and water the heck out of my backyard under the Big Bertha and Razors before the contest. No scientwific data, but felt good and scores were fixing some records.

73 Yuri
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