David,
As mentioned, the same antenna at different heights has different patterns. I
have high dipoles and low dipoles, high yagis and low yagis and the ability to
switch between them as needed. One antenna is never always superior to another
depending on the location of the station you are trying to listen to, the path,
and the time of day. Model up the antennas you can put on your property and
install the ones that look like they do what you want to do. Having the
ability to switch between two different antennas on the same band (especially
if they have distinct properties such as high and low angle of radiation or
horizontal or vertical polarization) always gives you the opportunity to
select the antenna that might work better under certain conditions.
Earl
N8SS
------------------------------
Message: 8
Date: Thu, 6 Nov 2014 08:55:30 -0600
From: "Matt" <maflukey@gmail.com>
To: <towertalk@contesting.com>
Subject: [TowerTalk] FW: Take off angle of yagi vs a wire antenna at
about 30'
Message-ID: <000401cff9d1$b5f272c0$21d75840$@gmail.com>
Content-Type: text/plain; charset="utf-8"
Hi David,
A dipole in the optimum direction at about 85' will produce similar transmitted
low angle ERP as your Mosley at 30', but should provide some advantage in
hearing low angle signals. I once had the opportunity to directly compare a
33JR @ 30' to a dipole @ 95' (dipole was fed with ladder line). The high
dipole would almost always hear DX much better than the low beam - I suspect
because it offered increased signal strength at low angle with decreased noise
at higher angle as compared to the low antenna. TX is about forward gain @
the required wave angle, receive is all about S/N... which are not always
the same thing. As an aside, the high dipole also made a significantly better
receive only antenna on the low bands as compared to a ground mounted vertical.
Hope this info is beneficial to you.
73
Matt
KM5VI
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of David
Gallatin via TowerTalk
Sent: Thursday, November 06, 2014 7:27 AM
To: TowerTalk@contesting.com
Subject: [TowerTalk] Take off angle of yagi vs a wire antenna at about 30'
Hello group and once again I thank everyone who helped with my previous post
about the concrete.
My set up: Mosley TA 33 JR tri-bander that will be at about 31 feet. The
question: I've been debating ways to get at 40-80 meters. I have a very small
lot so cant run the usual wire suspects and was thinking about making a mag
loop.
But I've also thought about an end fed Chameleon or 33' Ultimax at about 28
feet as I do have room to run one of those horizontal to a tree. These are
multi-banded antennas but I've never given considered using them on 20,15,10 of
course.
But then a thought occurred to me. Might the take off angles of the wire
antenna be different enough as to be beneficial for transmitting on those bands
and hitting different spots of the globe that the Mosley is skipping over?
73,
David, AA9G
ex W5DCG and KC9EEV
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