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
