Dave,
Aside from the issue at hand, and perhaps sans the
"misguided", I'm certain this "our hobby has
several generations of very misguided members who
have squandered millions of dollars." is true ;-)
73, Phil W7OX
On 7/13/16 5:48 PM, David Gilbert wrote:
I've played around with VOACAP a lot in the
past. Possibly you want to argue with it's
validity, but I can tell you that the percentage
of time it shows signals optimally arriving at
45 degrees is much less than the percentage of
time they arrive closer to 10 degrees ...
certainly for any kind of DX work and most of
the time for domestic work here in the U.S.
That depends upon the band, of course, and also
the time of the opening (optimum angles are
lower at openings and closings versus
mid-opening), but in general the best TOA's area
lot lower than most hams assume.
If low takeoff angles weren't generally
desirable our hobby has several generations of
very misguided members who have squandered
millions of dollars.
Dave AB7E
On 7/13/2016 5:02 PM, Wes Stewart wrote:
Jim, I've looked at your stuff in the past.
But, "improvement" is in the eye of the
beholder. The ionosphere determines the
optimum TOA, not the antenna. Taking heroic
measures to get the max TOA down to 10 degrees
(a near impossibility over dirt) when the
signals are arriving at 45 degrees is hardly
optimum.
Anecdotal evidence is mostly worthless but for
what it's worth, I have 48 entities worked on
160 meters from here in the desert using no
more than 500 watts into an inverted-V, apex at
45' ends at 6'. Everyone "knows" that this
can't possibly work because it radiates
straight up. (Except that it doesn't)
Wes
On 7/13/2016 3:07 PM, Jim Brown wrote:
On Wed,7/13/2016 12:03 PM, Wes Stewart wrote:
Ok, but I'm unclear about what "improves
radiation pattern" means.
Wes,
Take a look at the links I posted to my NEC
studies. There can be no doubt as to the
meaning of "improves radiation pattern."
BTW -- I do NOT agree that elevated radials
have much to do with establishing the take-off
angle. AND, more to the point, I view take-off
angle as absolutely the wrong way to look at
the vertical pattern of an antenna. A FAR
better approach is the one I used in those
antenna planning applications notes, for which
I posted links a few hours ago.
73, Jim K9YC
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