Jim I don't think that Tim is saying the 4sq is 6 dB better than his
beams. I read that as a 4sq is around 6dB of gain on a model. Maybe
I'm reading that wrong. Pretty sure if it was 6 dB better than a set of
tall stacks the entire world would be running 4sq on 40m and few would
be using beams.
73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com
On 27-Feb-19 3:02 PM, Jim Brown wrote:
On 2/26/2019 8:03 PM, Tim Duffy wrote:
With a good ground radial system (very important) here at K3LR - the
full size 4 square holds its own - almost 6 dB of gain over ground -
compared to a stack of W6NL Moxons (185 feet over 120 feet). The
vertical 4 square is a VERY good antenna for 40 meter DXing.
Soil quality also matters a lot for vertically polarized antennas,
while it does not matter for horizontal antennas. Radials help
verticals ONLY by minimizing losses in the ground they cover; soil
quality strongly affects the strength of the far field. K3LC wrote an
excellent tutorial on this that was published either in QEX or NCJ
something like 10 years ago.
This might, for example, explain why your analysis of the relative
effectiveness of your 4-square is different from Jeff's. My QTH in the
Santa Cruz Mountains has mostly rocky soil, so horizontally polarized
antennas are the winner on all bands except 160M. They're better on
160 because almost any horizontal dipole that could be rigged for 160M
is a LOW dipole. :) I had one at about 120 ft for several years when I
first moved here, and it rarely beat a Tee vertical with about 80 ft
vertical over on-ground radials, and the vertical was usually MUCH
better.
One blessing for 160 verticals at my QTH is that the 160M season
(winter) is our rainy season, and laying on top of that rock is a lot
of "duff," droppings from the trees that act like a big sponge to
retain the rain, temporarily improving soil conductivity. Once we've
had a lot of rain, my signal gets louder on 160M!
73, Jim K9YC
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