"Richard Clark" wrote in message
...
On Thu, 09 Sep 2004 13:11:02 GMT, "Jimmie"
wrote:

VSWR
reading for my antenna is 1.25:1 at the resonant frequency of my antenna.
Given the inaccuracies of SWR meters I figure I have a ground resistance
some where between 3 and 10 ohms.

Hi Jimmie,

How do you figure that?

73's
Richard Clark, KB7QHC

Mostly an educate guess, my AC test blows a 10 amp fuse to smithereens so I
figure less than 10. SWR is 1.25 to 1 This equates to about 40 ohms
impedance seen at the antenna base. This also agrees with my antenna
analyzer. Antenna is a full length 1/4 wl antenna on 20m. I was figuring 37
or soo for this. I know its a lot of by guess and by golly and I am aware
that there are better ways of finding out what the ground loss really is
but I'm not so anal that I reallly care. Given the SWR reading I figure
closer to 3 and a neighbor recently had lightning rods installed and the
installers measured theire ground resistance at 2.5 ohms so I am pretty
confident of my educated guess .

When I get my tower up 20 meters will be on a beam on top of the tower and I
plan to use the ground plane with a 40 M vetical 1/4 wave antenna. Ground
plane is made of 12 wires 12ft long connected to a 10 ft ground rod at the
base of the antenna. Do you think I should modify the ground plane. I was
thinking of at least adding 4 wires 1/4 wl long for 40, I really think this
may be a waste of time though. Also would existing ground plane be good for
80M.