I think the seemingly oxymoronic term "multi-monoband"
was coined to describe the concept used by Force 12
whereby multiple monoband yagi antennas share a common
boom. The concept is a little different than an "interlaced"
yagi in the sense that with the F12 antennas, the high frequency
elements are up toward the front end of the boom and the low
frequency yagi elements are in the back (imagine taking two
3 element monobanders, one for 15, and one for 10 and lining
them up with their booms placed end-to-end). This staggering
of the elements reduces the interaction found in traditional
"meshed" interlaced designs where high frequency elements
are stuck between low frequency elements and comes closer
to acheiving true monoband performance with a multi-band
antenna. At least thats my meager understanding of how it
works. Anyway, it seems like a very good design concept.
73 de Mike, W4EF......................
----- Original Message -----
From: "John Tait" <bravo@iol.ie>
To: "Mike" <W4EF@dellroy.com>; "force12e" <force12e@lightlink.com>;
<towertalk@contesting.com>; "Force12Talk" <force12talk@qth.com>
Cc: "Tom Schiller" <force12@fix.net>
Sent: Friday, February 01, 2002 9:43 AM
Subject: Re: [TowerTalk] Everything Works QST Article by N6BT
> WHAT in the name of the divine Dinny Flaherty is a "multi-monoband
> yagi"....??????
> WHY do people take such liberties with the Greek, Latin and English
> languages..??
> Multi means MANY......and mono means ONE...!!!
> Make up your minds guys...It's either a MULTI band antenna OR a MONO
band
> antenna
> It can NOT be both..
> It could however, be an "interlaced" yagi...which I suspect it is..
> Who's going to be the first to produce a square circle I wonder..???
> 73s
> de
> John EI7BA
>
>
> ----- Original Message -----
> From: "Mike" <W4EF@dellroy.com>
> To: "force12e" <force12e@lightlink.com>; <towertalk@contesting.com>;
> "Force12Talk" <force12talk@qth.com>
> Cc: "Tom Schiller" <force12@fix.net>
> Sent: Friday, February 01, 2002 6:48 AM
> Subject: Re: [TowerTalk] Everything Works QST Article by N6BT
>
>
> >
> > >
> > > 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
> > >
> > > --------------------
> > >
> > >
> > >
> > >
> > >
> > >
________________________________________________________________________
> > > Where do you get ICE bandpass filters & beverage matching boxes? The
> > > same place that pays for the hosting of this list: The eHam Store.
> > > Order online at http://store.eham.net.
> >
> -----------------------------------------------------------------------
> > >
> > > -----
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> > >
> > >
> >
> >
> >
> >
> > ________________________________________________________________________
> > Where do you get ICE bandpass filters & beverage matching boxes? The
> > same place that pays for the hosting of this list: The eHam Store.
> > Order online at http://store.eham.net.
> > -----------------------------------------------------------------------
> >
> > -----
> > FAQ on WWW: http://www.contesting.com/FAQ/towertalk
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> >
> >
>
>
________________________________________________________________________
Where do you get ICE bandpass filters & beverage matching boxes? The
same place that pays for the hosting of this list: The eHam Store.
Order online at http://store.eham.net.
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