[amsat-bb] Re: quadrafilar helix for 70cm- ambiguous design specs

[Bryan Klofas]

http://polysat.calpoly.edu/earthstation/documents/helix-microwavejournal-dec1970.pdf
--
Bryan Klofas, KF6ZEO


i8cvs wrote:
> Hi Art, KC6UQH
> 
> I would like to receive from you copy of the Microwave Journal December 1970
> Pgs 49-54 By Doctor CC Kilgus about the QFH Antennas.
> 
> Tanks
> 
> 73" de
> 
> i8CVS Domenico
> 
> ----- Original Message -----
> From: "Art McBride" <kc6uqh at cox.net>
> To: "'i8cvs'" <domenico.i8cvs at tin.it>; "'AMSAT-BB'" <amsat-bb at amsat.org>;
> "'Franklyn A. Ballentine, jr'" <art.ballentine at gmail.com>
> Sent: Thursday, October 01, 2009 7:09 AM
> Subject: RE: [amsat-bb] Re: quadrafilar helix for 70cm- ambiguous design
> specs
> 
> 
>> The most comprehensive info on QFH antennas is the Microwave Journal
>> December 1970 Pgs 49-54 By CC Kilgus.
>>
>> Art, KC6UQH
>>
>> -----Original Message-----
>> From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
>> Behalf Of i8cvs
>> Sent: Wednesday, September 30, 2009 5:35 AM
>> To: AMSAT-BB; Franklyn A. Ballentine, jr
>> Subject: [amsat-bb] Re: quadrafilar helix for 70cm- ambiguous design specs
>>
>> Hi Frank, KB1QZH
>>
>> The best starting point is the original article of the inventor of QHA i.e
>> Walter Maxell, W2DU
>>
>> In a separate email I have attached the above fundamental article.
>>
>> 73" de
>>
>> i8CVS Domenico
>>
>> ----- Original Message -----
>> From: "Franklyn A. Ballentine, jr" <art.ballentine at gmail.com>
>> To: "i8cvs" <domenico.i8cvs at tin.it>
>> Cc: "AMSAT-BB" <amsat-bb at amsat.org>
>> Sent: Tuesday, September 29, 2009 6:45 PM
>> Subject: Re: [amsat-bb] Re: quadrafilar helix for 70cm- ambiguous design
>> specs
>>
>>
>> I have a question along the same line.  Is the QHA in the ARRL
>> Satellite Handbook \ Antenna handbook, a good starting place?
>>
>> Thanks,
>> Frank B.
>> KB1QZH
>>
>> On Tue, Sep 29, 2009 at 11:17 AM, i8cvs <domenico.i8cvs at tin.it> wrote:
>>> ----- Original Message -----
>>> From: "Tim Goodrich" <tim at timgoodrich.net>
>>> To: <amsat-bb at amsat.org>
>>> Sent: Monday, September 28, 2009 9:45 PM
>>> Subject: [amsat-bb] quadrafilar helix for 70cm- ambiguous design specs
>>>
>>>> Hi All,
>>>>
>>>> The house I just bought precludes me from even using my arrow inside as
>>>> there must be something un-RF friendly in the walls. Therefore, I was
>>>> looking for a roof antenna and the October QST article on the QFH
>> inspired
>>>> me to build one. However, after doing some research, I have come up
> with
>>> two
>>>> sets of design specs and I'm unsure which one is correct.
>>>>
>>>>
>>>>
>>>> I converted everything from you're the 146Mhz QST model to 436Mhz.
>>> However,
>>>> when I plug that info into http://www.jcoppens.com/ant/qfh/calc.en.php
>>>>
>>>> The values it puts out are different in the "compensated length" field.
>>> The
>>>> only difference is this model calculates for a full turn as opposed to
> a
>>>> half turn, but the lengths shouldn't be as different as it says. Under
>> the
>>>> QST model, I get a wavelength of 688mm, but under the website's model,
> it
>>>> gives me a "compensated wavelength" of 729mm.
>>>>
>>>>
>>>>
>>>> The values I used to calculate are:
>>>>
>>>> 436
>>>>
>>>> 1
>>>>
>>>> 1
>>>>
>>>> 15
>>>>
>>>> 2
>>>>
>>>> .23
>>>>
>>>>
>>>>
>>>> Can anyone tell me which specs to use and/or explain this compensated
>>>> wavelength issue?
>>>>
>>>>
>>>>
>>>> Thank you,
>>>>
>>>> Tim
>>>>
>>>> KI6VBY
>>>>
>>> Hi Tim, KI6VBY
>>>
>>> Read please the book "REFLECTION" Transmission Lines and Antennas by
>>> M. Walter Maxwell, W2DU Chapter 22 The Quadrifilar Helix Antenna pages
>>> 22-1 to 22-23 and also
>>> "Experimental Investigation of Quadrifilar Helix Antennas for 2400 MHz"
>> The
>>> AMSAT Journal May/June 2004
>>> In a separate email I have sent to you both articles as an attachement.
>>>
>>> 73" de
>>>
>>> i8CVS Domenico
>>>
>>>
>>>
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>>
>>
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> 
> 
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