Nope, no jumping to conclusions here. And tnx for the info that so many of the
guys are running stacked yagi's on 80 now. Wow....... Things keep changing
faster than a fella can keep up with them.
-----Original Message-----
From: Jim Jarvis <jimjarvis@comcast.net>
To: towertalk@contesting.com
Sent: Sun, 3 Apr 2005 23:17:01 -0400
Subject: [TowerTalk] simultaneous Horizontal and Vertical antennas
TWO POINTS TO BE MADE HERE...
First...Jamesnf commented:
"Frequently, on 80 meters, they use
a four square vertical system and a low dipole yielding potent directional,
low angle radition for dx from the four square and an omni-directional high
angle signal to let the stateside crowd know they're using the freq! In
this
case, running the antennas in parallel means separate feeds from the shack,
possibly even from separate amps.
Note: please, no lectures directed at me folks. I don't condone this
practice, I just know it exists. Jim "
To which I respond:
Aachem's razor says the simplest answer is the most likely.
It IS true that some contest stations will take a low yagi and
aim it stateside, to help hold their dx frequency. Simplest way
to do it is to split the stack, and sacrifice 3dB. 3dB isn't
going to make a lot of difference on the dx side. I've done it from
several stations. It is sometimes effective.
Not only is it illegal to run multiple full-power amplifiers, it's
a lot of work to organize it. So much so, in fact, that nobody would
bother....to save those 3dB which don't matter. Methinks you jumped to
a conclusion. (besides, on 80, you won't get enough f/b on the array
to prevent the stateside competition from hearing you.)
The low antenna technique works well on 40 and 20...less so on 15 and 10,
because
there may not be short skip...and close-in guys won't hear you anyway.
Secondly....with respect to the original concept of running parallel
vertical and horizontal antennas to get multiple polarizations...
twaddle! The ionosphere will scramble the polarization, anyway...what
he's doing is simultaneously exciting high and low angles...(assuming
the vertical has a decent ground system.) He's also destroying the dipole
pattern.
I'd bet he'd get better results by switching between them and picking
the better antenna at any given moment.
n2ea
jimjarvis@ieee.org
_______________________________________________
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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