Hi Ed,
I have a 72 ft self supporting crank up tower with 20 foot of mast
protruding from the top of the tower. A Cushcraft 2 el 40m beam (shorty forty)
is just above the base of the tower at 73 feet. A Create 80 meter dipole is
mounted 9.5 feet above
it (at 82 feet) On the very top of the mast is a SteppIR 4el (20m-6m - 32 foor
boom) at 92 feet.
This means that the 80m dipole is mounted about in the middle of the two beams.
I originally had the 40m beam and SteppIR on the tower. Later I added the 80m
dipole
with the elements parallel to the beam elements. After I installed it I noticed
some interaction
to the 40m beam but not very much. There seemed to be nearly no interaction with
the SteppIR. However both the SteppIR and the 40 beam did not seem to perform
quite as well as before the 80m dipole was added. It was just one those things
that you notice by instinct and experience I have been a ham for 50 years and
have
played with many antennas over the years. I then decide to switch the 80m
dipole
so that it was parallel to the boom of the other beams. Everything seemed to
fall back into place (like before I installed to 80m dipole). The two beams
work as well
expected and the 80m dipole works well too. Also it seems the 80m dipole
performs
better when it is parallel to the beam booms (again "seems"...I was never of
course
able to compare it to being parallel to the elements).
If you are able to mount your dipole 15 feet above the SteppIR this might be
enough
to eliminate / minimize any interaction. I however, based on my experience I
would mount
it parallel to the SteppIR boom.
If possible (probably not so easy to do) try to rotate the 80m dipole 90 degrees
(from parallel to the boom to a right angles it) while monitoring the SWR
and your SteppIR on different bands to see if there is any change in the SWR.
Also at the same time monitor the SWR on the 80m dipole. If there is any change
it of course means some interaction.
Anyway the above is my experience..hope it is helpful...Good luck...
Lets us know what you decide on and how it works out.
73,
Dan, WA6URY
---------------------
----- Original Message -----
From: navydude1962@yahoo.com
To: Scott & Sherry Souva ; Robert Harmon ; towertalk@contesting.com ;
steppir@yahoogroups.com
Sent: Monday, February 07, 2011 3:19 AM
Subject: [SteppIR] 80 mtr dipole spacing above Steppir
This is an offshoot of a previous thread. I currently have an 80m rot. Dipole
five feet above my steppir and parallel to the boom.
I want to raise the 80m dipole about 15' above and have it parallel to the
steppir elements. Would look cleaner. Good or bad idea? Steppir would be at 70'
and dipole at 85'.
Pls advise. Thanks.
Ed NI6S
Sent from my Verizon Wireless BlackBerry
-----Original Message-----
From: "Scott & Sherry Souva" <ssouva@twcny.rr.com>
Sender: towertalk-bounces@contesting.com
Date: Sun, 6 Feb 2011 10:23:41
To: Robert Harmon<k6uj@pacbell.net>; towertalk
reflector<towertalk@contesting.com>
Reply-To: Scott & Sherry Souva <ssouva@twcny.rr.com>
Subject: Re: [TowerTalk] 40 mtr dipole spacing above tribander
?Bob,
I have a D40 sitting about 5 feet above my Tennadyne T-6 on a TX-455 tower.
The D40 elements are parallel to the T-6 elements and I have not detected
any issues with either antenna. The D40 is at 60 feet and delivers
outstanding performance.
73,
Scott
KG2S
-----Original Message-----
From: Robert Harmon
Sent: Sunday, February 06, 2011 1:14 AM
To: towertalk reflector
Subject: [TowerTalk] 40 mtr dipole spacing above tribander
I have been looking though the archives
in tower talk for info and haven't found anything as yet about my spacing
question.
I also emailed Force 12 but haven't received a response yet.
I have a Force 12 C3 and just acquired a used Cushcraft D40 rotatable dipole
for 40 meters.
I want to mount the 40 meter dipole above the C3 on the same mast. I would
like to know
the minimum spacing to avoid interaction and also if I should orient the
dipole so it is
parallel with the boom of the C3. Anyone have experience with spacing the
same or similar
antennas ?
thanks,
Bob
K6UJ
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