The elements on the Cushcraft XM240 are loaded with a combination lumped
inductor and capacitance hat. I believe they are resonate at around 18 MHz.
73, Mike W4EF.............
On 1/3/2016 12:08 PM, john@kk9a.com wrote:
How about omitting the linear loading and converting it to loading coils,
which is probably a better option anyway. My High-Q coil loaded 40m beams
are not resonant on 15m, one is about 17 feet away from my middle 15m beam
with no noticeable interaction.
John Kk9A
To: "tower" <towertalk@contesting.com>
Subject: [TowerTalk] how does one accomplish a 'stud' for elements?
From: "StellarCAT" <rxdesign@ssvecnet.com>
Date: Sat, 2 Jan 2016 09:04:51 -0500
Specifically adding something to a 4 element 40 to eliminate 15 meter
interaction? I believe Optibeam does this – not sure how they do it. Is this
just using the element with a parallel line tuned through a cap for max
current
on 15? If so any suggestions on how long to make it and where specifically to
put it on each element 1/2?
Or is there a way to use a relay, open normally, closed when on 15 that would
add some impedance to the antenna causing it to be detuned at 15?
Alternatively I can rotate the antenna 90 degrees but boy it would be so much
better not to have to do that to avoid interaction on 15.
thanks in advance,
Gary
K9RX
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