[amsat-bb] Re: Arrow and ELK comparative antenna tests

[i8cvs]

Hi John, N7JK

Since you are interested in accurate antenna gain measurements and
comparison I suggest you to read also the following articles:

ANTENNA GAIN MEASUREMENTS Part 1 : Technique- the fine points
of making accurate gain measurements without access to a professional
antenna range. by Fred Brown W6HPH
published on QST November 1982 pages 35 to 37

ANTENNA GAIN MASUREMENTS Part 2 :  Intrumentation- simple,easy
construction instruments permit a precise determination of antenna gain
by Fred Brown W6HPH
published on QST December 1982 pages 27 to 31

UHF ANTENNA RATIOMETRY : Inconsistent results in checking antenna
gain ? Here is a technique that can restore your faith in measurements and
speed up empirical designe by Richard T. Knadle W2RIW
published on QST February 1976 pages 22 to 25

73" de

i8CVS Domenico

----- Original Message -----
From: "John Kopala" <jkopala at gmail.com>
To: <amsat-bb at amsat.org>
Sent: Monday, April 25, 2011 11:29 PM
Subject: [amsat-bb] Re: Arrow and ELK comparative antenna tests


> One supplemental note on the testing of the Arrow and ELK antennas.
>
> I indicated that having both the transmit and receive antennas in the same
> plane with the ELK might have some advantages.
>
> I failed to mention that having the crossed yagi design of the Arrow
> isolates the 2 antennas from each other and may help to minimize UHF
> downlink desensing when transmitting on a VHF uplink.  This
> can vary greatly with the configuration and the radios used, but certainly
> would provide significant isolation when separate radios are used for the
> uplink and downlink.
> Recent posts on the Alinco DJ-G7 also highlight the fact that the radio
> itself my desense on one band when transmitting on the other.
> In that case, all the isolation in the world might not make any
> difference.
>
> John Kopala
> N7JK
>