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

Roberto iw5bsf at alice.it
Tue Apr 26 01:52:41 PDT 2011


Hello,hi support link W1GHZ Paul website:
http://www.w1ghz.org/small_proj/hna.zip
73 de iw5bsf Roberto
----- Original Message ----- 
From: "i8cvs" <domenico.i8cvs at tin.it>
To: "John Kopala" <jkopala at gmail.com>; "Amsat - BBs" <amsat-bb at amsat.org>
Sent: Tuesday, April 26, 2011 2:16 AM
Subject: [amsat-bb] Re: Arrow and ELK comparative antenna tests


> 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
>>
>
> _______________________________________________
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