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Old April 17th 05, 02:46 PM
Fred W4JLE
 
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Ed, this comes from years of practical experience in trying to achieve a
broad antenna.

With all due respect to the various "NEC" programs as well as Reg's program,
they are great for comparing antennas. In the real world environment of most
hams, results do not agree with the predicted on 75.

Why?, because few of us can get a 75 meter antenna any where near a half
wave length high and in the clear. While one may be able to model the real
antenna environment, I am not smart enough. I would suggest that you model
your particular 75 meter antenna, and then measure actual results as a fun
exercise.

Now to the original question, in spite of the data in QST, I have found
spreads of less than 15 feet in a practical environment will not achieve
your goal. YMMV.

We have got to the point in ham radio, we are measuring with a micrometer,
marking with a crayola, and cutting with an axe. I doubt that anyone in the
history of the world has calculated a 75 meter dipole, put it up, and made
no adjustments unless they mis-measured.


Heck for years we have used 468/F to cut our antennas and that is incorrect
as well! Don't rob yourself of the fun of trying something based on a
program. Last night, for example, I had an enjoyable ragchew with a fellow
in England, running my barefoot Icom 706 MKIIG on 75. My antenna is 40 feet
up at it's highest point. Anecdotal evidence for sure, but the QSO was fun
anyway!

Sorry to get so long winded... Good luck on your broad antenna experiments,
the journey is the fun part.

73 Fred W4JLE



"Ed" wrote in message
. 93.175...


Some things that do not work, "the bazooka", dual wires spread less
than 15 feet, and any of the antennas that are terminated folded
dipoles.


Fred, I appreciate your comments on my questions. Could you elaborate

on
your statement (above) that "dual wires spread less than 15 feet" do not
work? The QST article, Table 1, seems to indicate they do work, with a
spread of only 6 feet, or even 3 feet, for 75M dipoles.


Ed K7AAT