Gus, As long as one is twice or more the frequency of the other it should work fine. If you are using them as a feed for a dish the phase center of each one must be considered for best focus.73, Art,KC6UQH

-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Gus Sent: Wednesday, March 12, 2014 1:33 AM To: AMSAT-BB@amsat.org Subject: [amsat-bb] Question for the antenna gurus

Regarding axial-mode helix antennas, what happens if you build a helix for each of two different bands (like 2M/70cm), and mount them concentrically, on the same backplane? -- Gus 8P6SM The Easternmost Isle _______________________________________________ Sent via AMSAT-BB@amsat.org. 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