[TowerTalk] C-3 & TH7 comparison - a revision

L. B. Cebik cebik@utkux.utcc.utk.edu
Wed, 29 Apr 1998 17:21:58 -0400 (EDT)


> 
> No, hams are not crazy. Stacking antennas at HF is really done 
> not to get the 2 or so db of stacking gain it is to get
> a better take off angle pattern - it is this change in pattern
> that accounts for the 10 db changes in signals when switching 
> between the stacked antennas. 

If all someone needs is a better take-off angle, that is, lower, then a
stack is detrimental, since the antenna pair actually raise the TO angle
relative to the TO angle of the upper antenna alone.  However, the gain
does not hurt a bit and gives the operator a variety of TO angles using
the top only, the bottom only, and the pair together.  In variety, there
is success--but at the cost of erecting and maintaining the stack.

Although 2 dB is only 1/3 of an S-unit, in the margins or in the piles, it
can make the difference between being one of many or THE one heard.

-73-

LB, W4RNL

L. B. Cebik, W4RNL         /\  /\     *   /  /    /    (Off)(423) 974-7215
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