[amsat-bb] Re: Quadrifilar Helices
jeffh at network-services.uoregon.edu
Fri Nov 2 12:15:34 PST 2007
> Message: 5
> Date: Fri, 02 Nov 2007 10:33:09 -0700
> From: Dave Guimont <dguimon1 at san.rr.com>
> Subject: [amsat-bb] Re: Quadrifilar Helices
> To: "R.Haighton" <ve3frh at cogeco.ca>
> Cc: amsat-bb at amsat.org
> Message-ID: <200711021733.lA2HX9s4008456 at ms-smtp-03.socal.rr.com>
> Content-Type: text/plain; charset="iso-8859-1"; format=flowed
>> The Satellite Experimenters Handbook by Martin Davidoff K2UBC (1990 Pages
>> 8-15 & 16) and it's successor The Radio Amateur's Satellite Handbook (1998
>> pages 10-13 to 10-15) both have details of this antenna, its use and its
>> I recommend this book to all satellite experimenters and users, it may be
>> nearly 10 years old but the principles and information contained therein
>> have not changed.
>> Robin Haighton VE3FRH
>> Immediate Past President AMSAT
> That's exactly where I started, Robin, on page 6-20 of the original edition.
> But Maxwell's measurement produced a horrible
> VSWR.....I saw Marty later on at a convention,
> and I believe he said the same thing happened to him...
> It took me 4 iterations to get the antenna flat
> with no matching device...I of course did it at
> 435. But those dimensions translated very
> successfully to 2M satellite, 2M repeaters, and
> believe it or not to 2.4 gigs....In front of a dish, of course!!!
> I had seen other pictures of the antenna, and was
> very interested prior to Marty's excellent
> depiction of the construction details...
> I used a combination of 435 and 2M versions fixed
> at about 45?, and rotated in AZ only and worked
> very well with strong signal birds...
> Quadfilxxxxxxxxx has the dimensions for the 3,
> but the 2.4 gig computation is left as an exercise for those interested.
> Nice to hear from you, Robin....R U active on any of the birds??
> 73, Dave wb6llo at amsat.org
> Disagree: I learn....
> Pulling for P3E...
I found WB6LLO's 435 version easy to reproduce with good results.
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