Steve,
Just happen to be working on the same project myself at the
moment. Took down my 12 year old A3S to refurbish it and add
the 40 meter kit I acquired ten years ago while "horse
trading". You are right the instruction sheet could use
improvement. The QST review of the kit in March 1982 even
mentions that.
My observations follow:
First issue - My overall length for the driven element is
within 1/2 inch of what the chart says it should be for the
CW segment that I'm targeting. If looking for an error the
first place I would check is to make sure you got the "A2"
dimension correct. Note that it is measured from the CENTER
of the boom not the side. I missed that detail the first
time I put the antenna together. The other elements are also
within an inch or so. I guess I was willing to call that
close enough and instead rely on fine tuning it with the SWR
reading being what really matters.
Second issue - Another place where better pictures or even a
few words would have helped. Yes, the bracket gets mounted
under the hose clamp at the end of the tapered section of
the TK trap . My trap only measures 8 3/4" long from the end
of the trap to the end of the tube. However if you install
the angle bracket so its short end is pointing towards the
trap and the hat elements are mounted on the outside toward
the element tip then you do end up with the hat 9" away from
the trap end.
Hope this helps.
73
Patrick
W7TMT
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of
Clary, Steve
Sent: Friday, October 01, 2004 6:58 AM
To: towertalk@contesting.com
Subject: [TowerTalk] CushCraft Antenna measurements issues
A3S
Hello all. I was just wondering if any of you folks have
put together a Cushcraft A3S (10-15-20) or the 40 meter add
on (A743) recently and have run into any of these issues:
First Issue:
In the instruction manual, when assembling the elements, the
chart gives very clear measurements for all the distances
between the traps. It also gives a "Total" distance of the
entire element from end to end. Each element that I have
constructed and has exceeded the total distance (by an inch
or two), even though I have made precise measurements
between all of the traps.
It is as if the traps are actually longer than what the
instructions were originally written for. Please help me
understand.
Second Issue:
I have also purchased the 40 meter add on kit for this
antenna (A743). I can't really decipher from the
instruction manual how to attach the x-hat unit? Does it
get mounted to the element with a hose clamp, and if so,
should it be the same hose clamp that attaches the last trap
to the end of the element (tubing). It does seem like that
is the appropriate place for it, however, the instructions
call for a 9 inch separation between the x-hat and the last
trap. Even if you mount the hose clamp at the furthest
distance possible from the element (on the aluminum tubing
end), it comes within an inch shy of 9 inches.
Thanks
Steve
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