Thanks guys, construction is under way
I have a question, directors 3 4 5 of the first yagi then displaced by 6.5 inches come very close to some directors of the second offset yagi 6.5 inches.
Is it ok to just jump forward a bit to stop the clash ?
They come withing mm of each other
Did you find this ?
---------------------------------------------------------------------------- Andrew Rich VK4TEC [email protected] mailto:[email protected] http://www.tech-software.net
-----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Michael Tondee Sent: Friday, 28 December 2007 11:08 AM Cc: Amsat-Bb@Amsat. Org Subject: [SPAM] [amsat-bb] Re: 70cm yagi design Importance: Low
I second this. These antennas are easy to construct and there is no matching section to fiddle with. You can also construct a pair offset on one boom for RHCP or LHCP, even switchable just like any other satellite yagi but then you have to start dealing with phasing harnesses. I don't have an SWR analyzer for that task so I've just got 11 elements and 4 elements vertically polarized on 70cm and 2 meters respectively. They worked quite well when I had a rig! I'm trying now to find one I can afford so I can get back in the game. I miss it! 73, Michael, W4HIJ James Duffey wrote:
The Cheap Yagis by WA5VJB work great and are easy to make:
< http://wa5vjb.com/yagi-pdf/cheapyagi.pdf >
< http://www.wa5vjb.com/references/Cheap%20Antennas-LEOs.pdf >
Precise measurements of element length at 432 are important. You should strive for measurements of at least +/-1/16" with +/- 1/32" better. For the metric inclined you should strive for +/- a mm. These tolerances are possible with a good metal rule, but a bit more difficult with a wooden rule or tape measure. Cut the element a bit long and then file or grind to the proper length checking often.
I have made the 3, 4, and 6 element 2M versions and the 11 element 432 version. They all work well with sharp patterns. They have close to 50 Ohm impedance without adjustment. Let me know if you have any more questions, and more importantly, let us know how it all turns out. - Dr. Megacycle KK6MC/5
-- James Duffey KK6MC/5 Cedar Crest NM 87008 DM65
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