I have a 3-stack of 4-el SteppIRs below a Cal-Av 2D-40A beam. The booms of
all the beams are aligned.
The Cal-AV is a 2-element beam with a shortened boom (16 feet) but, unlike
the JK402T, the elements are full-size and both elements are driven.
The top SteppIR is only 14 feet below the 2D-40A. I have done extensive
testing of interaction and have found none. I think you'll be fine with 20
feet between the antennas.
That said, there's likely to be some interference if you're running SO2R or
multi. I do have some, but haven't found it to be an issue as long as I stay
away from harmonically-related frequencies, use stubs and/or filters, etc.
73, Dick WC1M
-----Original Message-----
From: kstover@ac0h.net <kstover@ac0h.net>
Sent: Wednesday, October 24, 2018 8:07 PM
To: Towertalk@contesting.com
Subject: [TowerTalk] SteppIR interaction with 40m beam.
Hello all.
I seriously considering a 4el SteppIR 20-6m and a JK Antenna's JK402T with
the 402T above the SteppIR around 20 feet.
Obviously the elements of the SteppIR aren't going to be a problem for the
40m beam as they can be set to a non-resonant length, but the 32' boom might
be (1/4 wavelength on 40m).
Anybody with a 4el SteppIR and a shorty 40 notice and interaction?
Thanks
R. Kevin Stover AC0H
ARRL, FISTS, SKCC, NAQCC.
"If it doesn't work the first time you push the button it won't work the
20th.Just stop."
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