[TowerTalk] Stacking Supplement

[L. B. Cebik]

A while back, I asked if anyone knew the whereabouts of a note on stacking
as related to antenna gain from Roger Cox.  My own--and similar searches
by a number of very helpful folks on the list--turned up nothing from the
archives, so I can only conclude that Roger must have sent the note to me
alone at the time.

My interest in the note was to give credit where it is due for the
original development via his modeling for the conclusion that the proper
stacking spacing for maximum gain (which may not coincide with
spacing for max F-B) depends upon the gain of the individual antennas 
involved, with the general progression that the higher the gain, the wider
the vertical spacing needed in a stack of 2 for max gain from the stack.

I had misplaced/misfiled my note from Roger and so cannot give you the
summary he gave of his modeling work.  However, to make the progressions
more generally available, I have placed a note on the subject--with credit
to Roger as the developer of the original idea (I do not know if the data
progression has an earlier source, although I have some papers that I am
beginning to work though on related subjects)--at my site on
"Supplementary Stacking" info.  It records a group of 11 antennas I
modeled for their nice sequence of gains and yields some interesting bar
graphs which may be useful to stackers.  I do not really expect anyone to
have a stack of 7 element Yagis on 120' booms on 20 to achieve the
theoretical 21+ dBi gain over ground, but they do show where the
progression leads--and they do generate all kinds of pleasant dreams.

I hope the info is useful.

My thanks also to those who led me--despite a warped memory of of the
first few paragraphs rather than the main thrust of the article--to the
October, 96 CQ and W6NGZ's 5-element beam.  It is an interesting 45' boom
model to go with Frank Donovan's 48' boom antenna and both 40' and 48'
boom models found in YA by K6STI.

-73-

LB, W4RNL


L. B. Cebik, W4RNL         /\  /\     *   /  /    /    (Off)(423) 974-7215
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37938-4443     USA      /  \   \   \ \       ||              cebik@utk.edu
         URL:  http://funnelweb.utcc.utk.edu/~cebik/radio.html




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