[TowerTalk] Take off angle of yagi vs a wire antenna at about 30 ft
Earl Morse
kz8e at wt.net
Thu Nov 6 10:38:43 EST 2014
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 at gmail.com>
To: <towertalk at 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 at contesting.com] On Behalf Of David Gallatin via TowerTalk
Sent: Thursday, November 06, 2014 7:27 AM
To: TowerTalk at 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
_______________________________________________
More information about the TowerTalk
mailing list