On Tue, 20 Sep 2011 17:17:58 -0400
Guy Olinger K2AV <olinger@bellsouth.net> wrote:
> I share the frustration over the very minimal amount of
>data out there.
>
> However...
> Erection of a 260 foot vertical in a testing
> environment...
G'Day Topbanders,
I am not sure how general a conclusions could be drawn
from my experience, but I have a set up that is somewhat
relevant to this thread, and have done some on the air
testing with it.
I have two verticals, about 2 meters apart. One is 21
meters tall and the other one is 28 meters tall with a
high Q center loading inductor to make it resonate at 1900
kHz (this is my 160 m antenna). This antenna is fed via a
low loss antenna coupler. The two antennas share a common
ground system, which is salt-water to the east and a
buried field of 40 radials of varying length between 30
and 120 feet long to the west. On 80 meters the shorter
antenna is a 1/4 wave vertical, while the longer one could
be considered to be a half-wave vertical.
I have done extensive tests on 80 meters, comparing the
two antennas towards the east. I have used the reverse
beacon network, and a couple of friends' SDR-s in Europe
for these comparisons. In tests from my Florida QTH,
towards the east (towards Europe) and the side where the
salt water is, the taller antenna has almost always been
better by 2 to 3 dB. Towards the west (and the land side)
I have not done enough testing to draw conclusive results,
but I feel that the 1/2 wave vertical is better in that
direction too.
I understand the 80 meters is not 160 meters, but...
I would be happy to set up a test sched with anyone to my
west or north-west, who is interested in carrying these
studies further.
73,
George, AA7JV
PS: BTW, I almost always use the 1/4 vertical on 80
meters, even towards the east, as going through the
coupler is a PITA (as Guy has pointed out).
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