All,
I have found this thread
(http://lists.contesting.com/_towertalk/2012-09/msg00356.html) about the
Force 12 Delta 240 performance in terms of F/B gain and I would like to
share my experience with the list.
The antenna is actually a Force 12 Delta 240/230 however the two extra
elements for 30 meters should not affect performance when comparing to the
Delta 240.
The antenna is located in the roof of a 7 stories building in city downtown,
(Bilbao, Spain) however the antenna is only 18 feet above the roof (waiting
to raise it). The SWR is 1.1 at 7029. I did not changed the factory settings
(I mean I use the pre-drilled settings)
For measuring the F/B gain I have used the most valuable tool I have found
in my 30 years as ham: the reverse beacon network
(http://www.reversebeacon.net/index.php) .So I have transmitted (around
7029, 100 watts) some minutes with the antenna beaming the USA (260 degrees
from my location) and then I have rotated the antenna 180 degreases beaming
80 degrees (Europe - Asia). As you can see in the results there is a good
F/B gain ratio in all the cases.
As I am not sure if the mailing list can tabulate properly the data I prefer
not to include the data in the mail but to include a link to an Excel file:
http://www.qsl.net/ea2bsn/Force_12_Delta_240_FB_ratio.xls
A picture of the antenna:
http://qsl.net/ea2bsn/Montaje/INSTALACION%20DE%20JOSE%20ANTONIO%20SHERATON%2
0051.jpg
73, EA2BS
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