[TowerTalk] Improving 6-mtr setup.....

[Avila, Edward]

LB, excellent feedback........just what I was looking fer.......many thanks!
73...ed

-----Original Message-----
From: cebik [mailto:cebik@utkux.utcc.utk.edu]
Sent: Thursday, November 09, 2000 8:55 AM
To: Avila, Edward
Subject: RE: [TowerTalk] Improving 6-mtr setup.....


>===== Original Message From "Avila, Edward" <EAvila@caiso.com> =====
>Okay guys, I've read the good book so don't bother with "flaming" me with
>theory, what I need is real-world experience improving my 6-mtr signal --
>wannabe "Big Gun!" HI....currently using 5-element yagi, so, in your
>experience, would I be better off stacking two 5-el yagis or going with a
>single, much larger beam? Height, power and receiver all remain constant!
Ed,

Actually, you can go either way.  On average, a director adds about a dB
when 
properly spaced, while a stack will add--with the right spacing for the 
beams--between 2.5 and 3 dB more gain.  Possibly, for the same gain, the
stack 
might be a bit less of a mechanical oad, since the boom length for the 2.5+
dB 
gain on a single antenna would make a very long antenna--even at 6 meters.
My 
experienece with studying separation for max gain suggests that 5 elements
may 
like a space of about a full wavelength in a stack, but the array should be 
modeled so as to also locate the stack separation that also gives the best 
F-B.  In a stack, as you change separation in small increments, the gain
peaks 
and F-B peaks do not always occur atr the same separation--hence it pays to 
analyze before making permanent changes.

Hope this helps a bit.

-73-

LB, W4RNL

L. B. Cebik, W4RNL      /\   *    \   \  \           tel: 865-938-6335
1434 High Mesa Drive   /  \/\ /\   \---\--\      e-mail: cebik@utk.edu
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