What is the best way to set up phased crossed yagis ?
Have an electric coax switch in the middle to switch from left to right circ polar ?
---------------------------------------------------------------------------- Andrew Rich VK4TEC vk4tec@people.net.au http://www.tech-software.net
Andrew, Simplest way is to use relay or switch to add a 1/2 wavelenght of coax to one antenna phasing line. This will shift the phase by 180 degrees added to the 90 degree phase shift will reverse the rotation. You can also swap the phasing line connections to the antennas, but this requires more contacts. For 70 cm and shorter wavelengths a coax type of relay should be used for best performance.
Art, KC6UQH ----- Original Message ----- From: "Andrew Rich" vk4tec@people.net.au To: "Amsat-Bb@Amsat. Org" amsat-bb@amsat.org Sent: Sunday, December 23, 2007 7:39 PM Subject: [amsat-bb] Crossed yagis
What is the best way to set up phased crossed yagis ?
Have an electric coax switch in the middle to switch from left to right circ polar ?
Andrew Rich VK4TEC vk4tec@people.net.au http://www.tech-software.net
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
To add to Arts reply: this is illustrated in Fig. 8-11 (page 8-10) of The Satellite Experimenter's Handbook - Martin Davidoff, 2nd Ed. and available from the AMSAT Store. This book provides in-depth information on a wide range of subjects from Leo to Heo. There are a fair number of example formula to assist one in just about any question one can ask about satellites.
This is timely question as I am about to retrofit my M2-436CP42U/G to switch polarity. My Heo array has been down for two years and now going back into service. I Love to work on antennas when its 10F and snow is on the ground ;-)
A very best to everyone at Christmas and in the New Year! Ed & Janet Cole KL7UW
At 09:51 PM 12/23/2007, kc6uqh wrote:
Andrew, Simplest way is to use relay or switch to add a 1/2 wavelenght of coax to one antenna phasing line. This will shift the phase by 180 degrees added to the 90 degree phase shift will reverse the rotation. You can also swap the phasing line connections to the antennas, but this requires more contacts. For 70 cm and shorter wavelengths a coax type of relay should be used for best performance.
Art, KC6UQH ----- Original Message ----- From: "Andrew Rich" vk4tec@people.net.au To: "Amsat-Bb@Amsat. Org" amsat-bb@amsat.org Sent: Sunday, December 23, 2007 7:39 PM Subject: [amsat-bb] Crossed yagis
What is the best way to set up phased crossed yagis ?
Have an electric coax switch in the middle to switch from left to right circ polar ?
Andrew Rich VK4TEC vk4tec@people.net.au http://www.tech-software.net
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
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
73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep dubususa@hotmail.com ======================================
Andrew, Yes to have the Yagis switchable is (almost) essential particularly on 2M where the polarization can change during a pass. I have a control box (homemade) which switches the Polarization and the pre-amps (on/off). Robin Haighton VE3FRH
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Andrew Rich Sent: December 23, 2007 10:40 PM To: Amsat-Bb@Amsat. Org Subject: [amsat-bb] Crossed yagis
What is the best way to set up phased crossed yagis ?
Have an electric coax switch in the middle to switch from left to right circ polar ?
---------------------------------------------------------------------------- Andrew Rich VK4TEC vk4tec@people.net.au http://www.tech-software.net
_______________________________________________ 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
participants (4)
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Andrew Rich -
Edward Cole -
kc6uqh -
R.Haighton