Some of you folks are confusing elements bent in a vertical plane with
elements bent in a horizontal plane. They are not the same.
Besides, the InnovAntennas claim that the rectangular loop elements give
lower noise, GREATER front-to-side, and "considerably" more gain than
conventional elements. Lower noise comes ONLY from a tighter pattern,
loop elements don't actually give greater gain unless they are open
enough (i.e., close to square) to act like stacked elements, and I'd be
surprised if anyone would even notice the effect of a side notch greater
than the 50 db or so that I've measured on my conventional four element
yagis.
It may indeed be, as the InnovAntenna web site claims, the use of loop
elements provides additional degrees of freedom to optimize spacing and
tuning of a yagi antenna, but I sincerely doubt that the result is as
significant as they claim ... and without them bothering to back up any
of their claims with data (modeled or measured ... I don't care) I will
persist in that disbelief.
73,
Dave AB7E
On 3/20/2013 5:26 AM, Joe Subich, W4TV wrote:
The Moxon is a good example of the effect of bent elements - gain and
front to back levels are more typical of a three element yagi but
front to side is not as good.
One has a two element yagi in which the designer has essentially traded
front to side and mechanical complexity for gain and feed impedance.
73,
... Joe, W4TV
On 3/20/2013 7:27 AM, David Robbins wrote:
yes, in a classic yagi with straight and parallel elements that is
true... but when you bend or make the driven element not a simple
half wave dipole then it can have an effect on the pattern by
itself.
Mar 20, 2013 01:18:45 AM, jim@audiosystemsgroup.com wrote:
On 3/19/2013 11:10 AM, Joe Subich, W4TV wrote:
They give the designer additional degrees of freedom with which to
control input impedance and side lobe structure.
I was with you until you said "side lobe structure." I don't claim
to know much a bout the design of Yagis, but I'm under the impression
that pattern is largely determined by the tuning and spacing of
parasitic elements. Am I wrong?
73, Jim K9YC
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