On 1/25/17 7:23 PM, john@kk9a.com wrote:
This is a half sloper so the tower is a radiator. Whether it works well or
not depends on the tower and other mounted antennas. I imagine that this is
addressed in the Antenna Handbook. You would likely have better results
shunt feeding the tower or using a wire vertical.
John KK9A
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 160m Slopers
From: jimlux <jimlux@earthlink.net>
Date: Wed, 25 Jan 2017 17:41:36 -0800
On 1/25/17 4:42 PM, Chuck Dietz W5PR wrote:
I have a 140' tower with several beams on it and I want to get back on
160m. I want to put up a 1/4 WL sloper, but my experience has been that it
will only barely cover 1/2 the band. I have measured out two slopers, one
133' long and the other 127' long. Can I feed both together with the same
feedline? (Adjusting the longer one first.)
Yes, and both might need adjustment.. There's something in the Antenna Book
about this kind of antenna. You also need to space the two wires apart a
bit.
Isn't this where it's a sort of V dipole, tower is half the V, the
sloping wire is the other half of the V. You adjust the length of the
wire to make the match "reasonable".
So, if you have two of those wires, you might be able to get a broader
band (or two humped) resonance.
You can certainly do it with a weird fan dipole - I had a inverted V
with two sets of wires for different bands (12 and 17)... one wire fell
off leaving the 17 meter wire on one side, and the 12 and 17 on the
other. Yes, it was detuned, but when I swept it, it still showed two
resonances..
Mind you, it was an evil beast to tune with lot of interactions (in it's
original and altered form).. Those sorts of experiences are what made me
a convert to tuners at the feedpoint - get the wire the approximately
right length and let the tuner worry about the exact match. The pattern
difference on a 6-8 meter long dipole as you go through 10,12,15,17,and
20m is not very much..
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