Re: [amsat-bb] Arrow modification
Doug,
I been thinking about this as well. One antenna (arrow) for those birds with antennas at 90 (SO-50), and another for those birds with them in line. I've been looking at parallel designs(think "trident") e.g. take my elk, use that for 2m, and have a clip-on parallel spot for a 432 or 1.2G beam.
Tired of doing the TX-90-degree-twist.
Bill W1PA
The various dual-band Moxon designs are in-line, too.
e.g. http://pp2rr.blogspot.com/2016/07/antena-dual-band-vhfuhf-moxon-yagi.html
Bill W1PA
Folks,
As we look at various designs, are we keeping the link budget in mind? If these are being used primarily with 5 watt HT's or an HT and a SDR how much gain on each band is required. Also, is there a requirement for a connection to each radio or a single connection for something like a D72?
John K4SQC
On Thu, Jan 3, 2019 at 2:23 PM Bill Acito w1pa@hotmail.com wrote:
The various dual-band Moxon designs are in-line, too.
e.g. http://pp2rr.blogspot.com/2016/07/antena-dual-band-vhfuhf-moxon-yagi.html
Bill W1PA
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I've built cheap yagi's with the 2m/70cm elements on the same plane ( http://www.druidnetworks.com/same-plane-cheap-yagi.jpg) and used them to work down to the horizon on all the FM birds - from a clear location of course. Check out the AMSAT facebook page from about a year ago, and my youtube channel for the videos if you're super interested.
According to WA5VJB's ubiquitous document ( http://www.wa5vjb.com/references/Cheap%20Antennas-LEOs.pdf) the plane alignment shouldn't matter so long as the elements aren't interacting with each other. He's a much smarter cat than me, and after building such gizmos based on his design, I have no reason to believe an arrow built in the same fashion wouldn't also do the trick.
-Dave, KG5CCI
On Wed, Jan 2, 2019 at 9:37 AM Bill Acito w1pa@hotmail.com wrote:
Doug,
I been thinking about this as well. One antenna (arrow) for those birds with antennas at 90 (SO-50), and another for those birds with them in line. I've been looking at parallel designs(think "trident") e.g. take my elk, use that for 2m, and have a clip-on parallel spot for a 432 or 1.2G beam.
Tired of doing the TX-90-degree-twist.
Bill W1PA
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Forgot to add - I've also built several 'sleeve driven' designs in my early days, and they only performed at a fraction as well as a proper driven for each band. If you're more interested in just straight up ease of construction without requiring a duplexer or 2 rigs, then it's certainly an option. But if you care about hearing the bird < 15° then you'll get superior performance using a individual band driven design.
-Dave, KG5CCI
On Wed, Jan 2, 2019 at 9:57 AM David Swanson dave@druidnetworks.com wrote:
I've built cheap yagi's with the 2m/70cm elements on the same plane ( http://www.druidnetworks.com/same-plane-cheap-yagi.jpg) and used them to work down to the horizon on all the FM birds - from a clear location of course. Check out the AMSAT facebook page from about a year ago, and my youtube channel for the videos if you're super interested.
According to WA5VJB's ubiquitous document ( http://www.wa5vjb.com/references/Cheap%20Antennas-LEOs.pdf) the plane alignment shouldn't matter so long as the elements aren't interacting with each other. He's a much smarter cat than me, and after building such gizmos based on his design, I have no reason to believe an arrow built in the same fashion wouldn't also do the trick.
-Dave, KG5CCI
On Wed, Jan 2, 2019 at 9:37 AM Bill Acito w1pa@hotmail.com wrote:
Doug,
I been thinking about this as well. One antenna (arrow) for those birds with antennas at 90 (SO-50), and another for those birds with them in line. I've been looking at parallel designs(think "trident") e.g. take my elk, use that for 2m, and have a clip-on parallel spot for a 432 or 1.2G beam.
Tired of doing the TX-90-degree-twist.
Bill W1PA
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (3)
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Bill Acito -
David Swanson -
John Kludt