It's not off topic at all. And an important question.
I owned a 50-6 and used it for many years. I thought it work reasonably well
but I never modeled it. Later I found out that it has less gain than a dummy
load but at 87 feet that wasn't obvious. This is a very old design NOT done
by computer and is a bad antenna. The 50-6S on the other hand is computer
designed by I believe Joe Reisert W1JR when redid all those bad Cushcraft
designs when he became chief engineer some years ago. The 50-6S works just
fine as is. If you use a modeling program to redesign the spacing and
element lengths on the 50-6 you can make a decent antenna out of it. But
don't use it as is.
I covered how to look at VHF commercial yagis in my column. Unfortunately
you have to know who designed it and when it was designed. You are looking
for a computer design done by someone with reputation for designing decent
antennas. Most recent designs done in this century or most of those in the
1990's work well. Those done before that often do not work well. There are
lots of good designers out there K1FO, K6MYC (M2), W1JR and VE3BQN (more
recent Cushcrafts), K1JX (Ariane Arrays, C3I 6 meters), WB0DGF (HyGain more
recent designs), anything made by Wimo in Germany [DK7ZB] and K1WHS
(Directive Systems) are among those who come to mind though there are others
as well especially in Europe.
All that said, you probably don't have time to fix that antenna before the
CQ contest. Put it up and hope for the best. But don't leave it up. Fix it
before next spring/summer Es season.
73 Gene W3ZZ
World Above 50 MHz
FM19jd MD
50 => 10 GHz
Grid Pirates Contest Group K8GP
Member, CQWW Contest Advisory Group
-----Original Message-----
From: Darrell W4CX [mailto:w4cx@bellsouth.net]
Sent: Saturday, July 14, 2007 10:00 AM
To: vhfcontesting@contesting.com
Subject: [VHFcontesting] Difference between Cushcraft 50-6 and A50-6S ?
Pardon the (slightly) off-topic post....but I'm DESPARATE!! ;-)
Does anyone know what the diff is between the Cushcraft A50-6 and A50-6S 6
element beams? Or if there IS a difference? I have what I believe to be
the earlier A50-6 which has a 7-piece boom, and the current S model looks to
have a 3 piece boom. That's the only manual I can find on-line, but the
element spacings seem to be much different. There are no labels on my beam,
just faded black and red lines for element mounts. Desparately seeking
assembly instructions for the older A50-6 model to prep for next weekend's
CQ VHF contest. Thanks!!!!! Darrell W4CX
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