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" <[email protected]> > To: "'i8cvs'" <[email protected]>; "'AMSAT-BB'" <[email protected]>; > "'Franklyn A. Ballentine, jr'" <[email protected]> > 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: [email protected] [mailto:[email protected]] 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" <[email protected]> >> To: "i8cvs" <[email protected]> >> Cc: "AMSAT-BB" <[email protected]> >> 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 <[email protected]> wrote: >>> ----- Original Message ----- >>> From: "Tim Goodrich" <[email protected]> >>> To: <[email protected]> >>> 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 >>> >>> >>> >>> _______________________________________________ >>> Sent via [email protected]. Opinions expressed are those of the author. >>> Not an AMSAT-NA member? Join now to support the amateur satellite > program! >>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >>> >> >> >> _______________________________________________ >> Sent via [email protected]. Opinions expressed are those of the author. >> Not an AMSAT-NA member? Join now to support the amateur satellite program! >> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> >> __________ Information from ESET NOD32 Antivirus, version of virus > signature >> database 4468 (20090929) __________ >> >> The message was checked by ESET NOD32 Antivirus. >> >> http://www.eset.com >> >> >> >> >> __________ Information from ESET NOD32 Antivirus, version of virus > signature >> database 4471 (20090930) __________ >> >> The message was checked by ESET NOD32 Antivirus. >> >> http://www.eset.com >> >> > > > _______________________________________________ > Sent via [email protected]. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
