----- Original Message ----- From: "John Marranca, Jr" KB2HSH@amsat.org To: amsat-bb@amsat.org Sent: Thursday, November 01, 2007 2:46 PM Subject: [amsat-bb] Quadrifilar Helices
Does anyone know of a website or of construction plans for an 70 cm Quadrifilar Helix antenna? I have heard that they work quite well for an omni-directional LEO antenna. I am looking for an improvement over my Eggbeaters, which have been excellent thus far.
Thanks
John KB2HSH
Hi John, KB2HSH
Radio Rivista 10/1998 pages 23 to 30 carries out an article specific for a Quadrifilar Helix Antenna designed for 70 cm. The article is in italian but you can follow the drawings and pics and since it is difficult for you to find Radio Rivista I have sent to you a zipped file of the article in a separate email wich is 2.71 MB long.
AMSAT JOURNAL May/June 2004 pages 6 to 10 carries out an article specific for a QFA at 2400 MHz but there are conversion factors in it to scale the antenna for 70 cm In addition there are general informations on how to wound both coils to get RHCP or LHCP as well to connect the loops to get backfire or endfire radiation.
Best 73" de
i8CVS Domenico