Stan, this stack should work!
I have 2 fullsize 3 EL yagis (40' boom) stacked at 140' and 70'. It is
sometimes difficult to notice sharp effect on RX but on TX the stack is the
best 99% of the time!
Have you asked A-B-both reports from guys in the air?? If they tell you that
they don't notice difference there is something wrong with your system. I
get constantly reports like: lower-59, upper-59+10, both-59+20. I do not
tell them which is which before!!!
Even closer range EU stations give me best reports on stack usually.
But on RX I notice greatly improved pattern for the stack versus single
antenna. The modelling confirms that. The stack has much better F/B and F/S
what concerns high angle local signals. It is remarkable!! When beaming to
US I can hear a Russian station on upper antenna 59 but with stack he is
down in the noise.
The stack is too good for contest as a single antenna. I cannot work contest
without splitting some power to low dipole. As soon as I beam to US the
Russians will land on me to CQ and when beaming to JA, EU guys take the
frequency, impossible:)
Many guys told me beforehand that the lower antenna would not be much of
benefit at so low height and I would too just as well with the upper antenna
only as with stack - THEY COULD NOT HAVE BEEN MORE WRONG!
I know the modelling gives just 1-1.5 dbi advantage to stack but real life
is different!
73
tonno
es5tv
----- Original Message -----
From: "Stan Stockton" <stan@aqity.org>
To: <towertalk@contesting.com>
Sent: Sunday, February 15, 2004 6:41 PM
Subject: [TowerTalk] Stacking Problem
Any ideas on my dilemma would be appreciated.
I have a couple of 3L 40M yagis that are stacked at 150' and 70'. They are
gamma matched (will change to split feed in warmer weather) and are
switchable (upper, lower, both) with using an Ameritron RCS-4. The power
split is good but I have yet to see an instance of a station that was better
using both antennas as compared to the top one. In some cases they appear
to be the same but the two together are never noticeably better.
Is there any possibility that the RCS-4 is causing the problem with whatever
scheme is used to apply voltage in various configurations through the coax?
Am thinking seriously about replacing the coaxes this afternoon with long
enough ones that I can wind an RF choke at the feedpoint to each antenna and
also replacing the Ameritron with a high quality Transco switch I have
laying around.
Any feedback would be appreciated, especially if someone has reason to
believe the problem is in using that RCS-4.
Stan, K5GO
_______________________________________________
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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_______________________________________________
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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