>
> So, Tom (W8JI), where in the QST article do I state tribanders have
> negative 10dB gain
> and where in the article do I describe the ionosphere in such a manner?
>
My friend John and I were discussing this controversy this afternoon, so
when I came home from work, I decided to pull out the QST article and see
for
myself. On page 49 of the July 2000 issue of QST there is a graph (figure 2)
which plots relative "enjoyment" versus antenna gain for various types of
antenna ranging from a lightbulb up to "Large mono/multi-monoband stacks".
The horizontal scale is a little hard to interpret (I am not quite sure
where the
+8dBd point lies), but if you assume the horizontal scale is linear, then
this
graph shows that a "Low efficiency Trapped triband Yagi" at ">35 feet" is
around 5dB down from a "High efficiency trapped triband Yagi" at ">35 feet".
Likewise, using the same assumptions, this would put the "Low efficiency
trapped triband Yagi" at ">35 feet" 7.5 dB down from a "2 ele Yagi/smaller
multi-monoband" antenna at "> 35 feet" and 10.3 dB down from a "Larger
mono/multi-monoband Yagi" type antenna at ">35 feet".
Of course, the descriptors "Low Efficiency" and "High Efficiency" for the
"Trapped triband Yagi" are never clearly defined, nor is the size of the
"Trapped triband Yagi". A lot is left to the imagination (is he talking
about
a TA33JR or a TH7DXX?).
Several longtime hams (all of them EEs) who I know, all came away
with same impression that this article, although both very interesting and
very entertaining, was borderline advertising for Force 12. I had the same
reaction. I thought the article was generally interesting and informative. I
really enjoyed the story about the curtain array on Saipan, and Tom's
WAC exploits with the "illuminator". BUT I did come away with the
impression that the relative positions of the multi-monoband yagis (Force
12???) versus the trapped triband yagis (the competition???) were a bit
contrived. Although I surely couldn't prove it, this part of the article
smelled like a sell job to me.
As far as the reference to the non-linear ionosphere, I couldn't find
any. One could infer that this is weakly implied in Tom (N6BT's)
musings about the seemingly inexplicable huge differences between the
curtain array and the tribanders on Saipan, but in my opinion that would
really be a serious stretch. BTW, I suspect the huge differences between
the two antennas are a combination of poor S-meter calibration (very
common) and very a big gain advantage at very low takeoff angles for
the curtain array (it was, after all, very late in the evening on 15 meters
when you would expect takeoff angles to be very low). Perhaps
someone should model this?
73 de Mike,
W4EF.............................................................
> The answer is that W8JI's claimed statement from me is no place in the
> QST article, nor
> in any other of my writings. Fortunately, the QST article is in the
> public domain and every
> one can check it for themselves and not depend upon W8JI for
> information.
>
> BTW, my QST article was not written for fun, although the thought of
> using a lightbulb
> might strike some as humorous or at least entertaining. I did enjoy
> working ZD8Z to
> complete Worked All Continents in 2 days on 10 CW using 120 watts and
> the lightbulb, but
> it was a serious article to open our collective eyes on how important
> our antenna is to
> our enjoyment of amateur radio. On the other hand, the 3 element, phased
> lightbulb array
> I did after the article was done for fun and even though it was
> directive and could take
> a KW, it still was a lousy antenna! Thankfully, there were others with
> good enough
> antennas that enabled making some QSO's with both lightbulb "antennas."
> As the article
> was entitled, "Everything Works", the question remains, "How well and
> compared to what?"
>
> 73, Tom, N6BT
>
> --------------------
>
>
>
>
>
> ________________________________________________________________________
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