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Old March 7th 05, 08:36 PM
 
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Yes Richard that is exactly the case.
I have a case where F/B is at
the same frequency as max gain and I have not come across that before
so I asked those well versed in antenna design if this had been discussed
before,
Yes, it is an alternative to a yagi but nowhere as simplistic to build, for
that the yagi is hard to beat, As it happens the feed point impedance of
less than 2:1
at 50 ohms is easily obtained across the 20 meter band , the primary design
It compares to a 60 foot boom yagi and change of feed point can produce
higher impedance
but its beam width is not as narrow , the
elevation angle for max gain (TOA) is 10 degrees which is some what lower
than the norm
.. I have been working on this design for some time now and have all the
parts
made for a actual antenna, The winter has been
very harsh in the midwest but with good weather tomorrow I should be able
to put it together and put it up as there is no need to use the prop pitch
rotor
which is hard to install in cold or blustery weather as I get older.
.. The turning radius by the way is somewhat less
than a tight two element yagi and is of a design where frontal side lobes
have not
come into play. Because of mechanical difficulties I do not see it replacing
a yagi
but that was not the intent in the first place, I just like to explore and
experiment
and try to work from first principles rather than be tied to well known
paths of the past
As a point of interest Roy I use 300 segments per halfwave length. to double
check
my designs but who knows ,it may still be a case of garbage! If the antenna
is not
broken then I have not tried hard enough and I have broken many antennas in
my time
As a point of interest I would direct you to past postings where I describe
close coupling
to the driven element to attain for an impedance of choice and can be
adapted
for use in any array.You may remember Roy checking out one of my designs on
his page
( 13 elements on a 60 or 80 foot boom ) ere coupling achieved the 50 oihm
feed
as desired

Regards
Art