I erected a 50 ft self-supporting grounded aluminum tower last fall,
with a triband beam as a top load. I installed 137 radials 30m long
(because I could!). I first shunt fed it on 160m and it works well. I
added 80m shunt feed this spring and it is superb. I modeled 40m and
30m in NEC4.2. It should work great shunt fed on 40m where it is ~1/2
wave, but the 30m pattern is terrible with a high angle main lobe - just
too tall.
On 7/3/2017 7:37 PM, Dale Putnam wrote:
The delta loop corner fed. Which corner? Makes a huge difference, doesn't it?
Make this a great day
Dale
On Jul 3, 2017, at 5:34 PM, Cecil Acuff <chacuff@cableone.net> wrote:
We've run balloon supported 1/4 wave and 3/8 wave wires over our buried radial
field with great results for contests. The balloon is a pain with any weather
or wind but loads of fun.
Cecil
K5DL
On Jul 3, 2017, at 6:00 PM, Herbert Schoenbohm <herbert.schoenbohm@gmail.com>
wrote:
Many have tried balloon or kite supported 5/8 wave verticals on 160 with
disappointing results. I used to have a 308 self supporting tower which i
could use at night on 160 but it never ever beat a corner fed delta loop
supported by the same tower.
On Mon, Jul 3, 2017 at 6:38 PM, Peter Voelpel <dj7ww@t-online.de> wrote:
Please check the pattern on 60 and 40m where the 37m high vertical is going
to be used.
You certainly will see the high angle lobes.
73
Peter
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Charles
Moizeau
Sent: Dienstag, 4. Juli 2017 00:10
To: Herbert Schoenbohm; TopBand List
Subject: Re: Topband: 160 meter 1/4 vertical
The free-space pattern of current in a vertical (and also horizontal)
antenna is crescent shaped with its maximum at the midpoint, and a minimum
at each end. It shows nothing that could be termed an extraneous lobe.
Any
such lobes would seem to be the result of improper matching, or more
likely,
the fact that in the real world such an antenna is in an environment that
is
certainly not free space.
higher angles.
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