I have been clobbered every time I mention this.
Is there some one other than me that knows the following????
I had read in a Hand Book for the 1930's the 3 wire folded dipole and 2 wire
folded dipole had a couple factor of 1. This would make this antenna the
preferred driven element for a long yagi.
Folded dipoles are all so used when installations require long lengths of feed
line.
Back when the Bazooka or Double Bazooka or other wise now known as coaxial
antenna back around 1970 I think when I saw it in Ham Radio Mag.. Its coupling
factor was around 0.9
No some had told me that later on the coupling fact was really Velocity Factor.
Now how can the velocity factor gets interpreted as to how well a driven
element couples when compared to gamma match elements or Dipole or a folded
dipole or bazooka?
----See, "Ham Radio Techniques - 160-Meter Antenna Problems and Solutions," Ham
Radio magazine, Pg. 49, March 1990. A 3-wire version is also proposed to
increase the radiation resistance by 9x. In the single and multi-wire folded
versions the ground loss resistance remained constant. Note that Bill was
obtaining his results from the K6STI antenna modeling software he was using. I
am not familiar with that program's capabilities or accuracy and it is clear
from the article he believed the results he obtained from it. It was the early
days of NEC programs for PCs and many of us were just learning how to use and
apply the antenna simulation programs.
It is impossible to know the basis for his errors in this case. But Bill's
contributions to amateur radio were vast and valuable and greatly overshadow
this one slip-up.
'73, Thomas - ac7a (Tucson) -----
Stay on course, fight a good fight, and keep the faith. Jim K9TF/WA9YSD
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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