[TowerTalk] stacking xm240 cushcraft

[David Hachadorian]

----- Original Message ----- 
From: "jorge rios" <jorgerios18 at hotmail.com>
To: <towertalk at contesting.com>
Sent: Tuesday, January 25, 2005 2:48 PM
Subject: [TowerTalk] stacking xm240 cushcraft


hi im jorge xe2www from mexico ,im looking for some
help about the stacking subjet.
i have a xm240 in the top of my 120feet tower and i
have another one i its box but im thinking to install
it on the tower below the first one that i have on the
top ,i know that my tower doesnt turn but 85% of the
times i work pointing to north east i have the wxob
stack mach from array solutions it gives me the option
to match 3  antennas or two or just one ,i would like
to know if someone here can give me more information i
want to insatll the second antenna below the other
(looking for the correct  distance betwen the two of
them) i will use it only when i have my antenna
pointing to the north east ans if a need to turn my
upper antenna to another direction i will work only
with the one of the bottom,anyway im only looking for
comenatries,because i want to experiment with them
because i have the equipment lying arround in my
house,thanks for your comentaries
-------------------------------

That 120' antenna is at a perfect height for your
location, especially at this part of the sunspot cycle.
I'd put the second one at about 80'. I think if you put
it any lower, you will be unhappy with it when your
high antenna is pointed in another direction. 40'
separation between the two antennas should give you a
dB or two of stacking gain when they are fed in phase.
10 minutes of analysis with the program YT is behind my
advice. Perhaps someone will put more effort into a
better model.


Dave Hachadorian, K6LL
Yuma, AZ