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Re: Quadrifilar Helices




> ------------------------------
> 
> Message: 5
> Date: Fri, 02 Nov 2007 10:33:09 -0700
> From: Dave Guimont <dguimon1@san.rr.com>
> Subject: [amsat-bb] Re: Quadrifilar Helices
> To: "R.Haighton" <ve3frh@cogeco.ca>
> Cc: amsat-bb@amsat.org
> Message-ID: <200711021733.lA2HX9s4008456@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
>> construction.
>> 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.
> 
> http://home.san.rr.com/doguimont/uploads/
> 
> Nice to hear from you, Robin....R U active on any of the birds??
> 
> 
> 
> 
>             73, Dave wb6llo@amsat.org
>                     Disagree: I learn....
> 
>                Pulling for P3E... 
> 
> 
> 
> 

I found WB6LLO's 435 version easy to reproduce with good results.

-- 
Jeff
KK7WR
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