RadioBanter - View Single Post

January 31st 05, 01:37 AM

On 30 Jan 2005 16:51:17 -0800, wrote:

Well...Depends on what part of town...On the coast, it's great. A 30...
But in town, they rate it as about a 15. But that would vary greatly
I'm
sure...I'm in a suburban area, so I might be maybe a "20" ???
I know that I had very mediocre results using ground mounted verticals.
I had one with 32 full length radials, and it was poor compared to my
ground plane at 36 ft, with 4 radials. It was probably about as good as
Cecils vertical he ran....LOL...:/ MK

Hi Mark,

You have to think deeper into the ground than the thickness of
concrete or asphalt. Unless the project developer scraped off the top
6 feet and dumped it into Galveston Bay for fill, and then backfilled
your neighborhood with industrial waste.... RF and your antenna is
looking at a BIG foot print below it from your antenna's elevation
(probably a greater boon than ground mounted - your experience seems
to support this).

This means that when your RF first strikes earth at a DX angle of 5 to
10 degrees, it is a vastly bigger surface than that seen with a ground
mount because that ray strikes further away. (About half a mile away,
if I did my Trig right.) Instead of illuminating your driveway and
street, the elevated vertical is lighting up 100s of acres that
averages the ground conductivity over lawns, streets, gardens, homes,
lots....

Off hand, I would say the modeler with higher ground settings is
validated by your experience and conforms to your environment.

73's
Richard Clark, KB7QHC