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Re: Need advice on circular polarized antennas
by Wendy and Terry Osborne 26 Dec '23

26 Dec '23

Hi Joe, The late Domenico I8CVS, designed a switcher that used horizontal and vertically polarised yagis to obtain circular polarization, both RHCP and LHCP as well as horizontal and vertical. It was described in the AMSAT Journal March/April 2007 and May/June 2007. I've put the articles in dropbox here: https://www.dropbox.com/scl/fo/ne4o6ham0xfwovfdz004a/h?rlkey=sl2jswt7mlf1fn… Many years ago I made up a couple of these for the FM Broadcast band and can confirm that the switching system works fine. Merry Christmas and 73, Terry Osborne ZL2BAC On 25/12/2023 6:08 am, Joseph Amato via AMSAT-BB wrote: > I’m looking for some advice on antennas for 2 m/70 cm satellite operation. Presently, I have home-brew yagis for each band, horizontally polarized. To eliminate fading due to satellite rotation, I want to replace these antennas with circularly polarized ones. But the new antennas need to be relatively lightweight, because I have to lug them up on a ladder to mount them, and, well, I’m not as young as I used to be. I have been considering the WiMo circular polarized antennas (#18010 and 18011), but would first like to hear from people who have experience with them. I like to build things myself, but the WiMo design looks cleverer than anything I’ve been able to come up with so far. Any advice? Thanks! > > Joe K1MNY > > ----------------------------------------------------------- > > Sent via AMSAT-BB(a)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. > Acceptable Use and Privacy Policies available at https://www.amsat.org/about-amsat/ > > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/[email protected] > To unsubscribe send an email to amsat-bb-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org

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Re: Need advice on circular polarized antennas
by Bill Booth 26 Dec '23

26 Dec '23

On 25/12/2023 5:57 p.m., Pat Kilroy via AMSAT-BB wrote: > */RHCP <=> LHCP switching/* is not worth the added complexity I agree. I have a set of KLM 2m/440 sat antennas that have the switching but never hooked up nor used preamps. These antennas are 20+ years old and worked on early AO6 and all the ones today just fine. -- Bill Booth VE3NXK Sundridge ON, Canada Lat: 45.741290 (45° 44' 28'' N) Long: -79.457431 (79° 27' 26'' W) Grid Square FN05gr Visit my weather WebCam athttp://www.almaguin.com/wxcurrent/weather.html Organ and Tissue Donation - The Gift of Life Talk to your family. Your decision can make a difference.

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Re: Need advice on circular polarized antennas
by Pat Kilroy 25 Dec '23

25 Dec '23

I HAVE FOUND that *RHCP <=> LHCP switching* is not worth the added complexity, RF losses, cost, and lack of reliability for most Amateur Radio applications. Exception: If you are running an official ARISS Telebridge ground station, an AMSAT OSCAR command station or perhaps a Primary SatNOGS ground station. My 2 USD cents. Just sayin'! DE Pat N8PK-FM19 On Sun, Dec 24, 2023 at 2:20 PM Eduardo PY2RN via AMSAT-BB < amsat-bb(a)amsat.org> wrote: > Just make it polarization switchable: vertical / horizontal, simpler and > almost same result. > > 73 > > Merry Christmas to all. > > Ed PY2RN > > On Sunday, December 24, 2023 at 02:08:32 PM GMT-3, Joseph Amato via > AMSAT-BB <amsat-bb(a)amsat.org> wrote: > > > I’m looking for some advice on antennas for 2 m/70 cm satellite > operation. Presently, I have home-brew yagis for each band, horizontally > polarized. To eliminate fading due to satellite rotation, I want to > replace these antennas with circularly polarized ones. But the new > antennas need to be relatively lightweight, because I have to lug them up > on a ladder to mount them, and, well, I’m not as young as I used to be. I > have been considering the WiMo circular polarized antennas (#18010 and > 18011), but would first like to hear from people who have experience with > them. I like to build things myself, but the WiMo design looks cleverer > than anything I’ve been able to come up with so far. Any advice? Thanks! > > Joe K1MNY > > ----------------------------------------------------------- > > Sent via AMSAT-BB(a)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. > Acceptable Use and Privacy Policies available at > https://www.amsat.org/about-amsat/ > > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/[email protected] > To unsubscribe send an email to amsat-bb-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> > Virus-free.www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> > <#m_-8443413110256803103_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > > ----------------------------------------------------------- > > Sent via AMSAT-BB(a)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. > Acceptable Use and Privacy Policies available at > https://www.amsat.org/about-amsat/ > > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/[email protected] > To unsubscribe send an email to amsat-bb-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org -- Pat Kilroy 1

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**News Bulletin** 2023 Year End SSTV Event!
by Frank Bauer 25 Dec '23

25 Dec '23

December 25, 2023 - Amateur Radio on the International Space Station (ARISS) announces a special SSTV experiment to be held this week. The ISS Voice Repeater will be our downlink and several ARISS selected ground stations around the world will serve as SSTV uplink stations. Two special images will be sent on 437.800 MHz using PD120 formating. This limited experiment will be conducted on several passes over Europe, Australia and the USA between Wednesday Dec. 27 to Saturday Dec. 30, 2023. We hope radio enthusiasts will download the images and follow along with the event. We appreciate all hams holding off from using the repeater for voice contacts during the event. Watch www.ariss.org <http://www.ariss.org> and ARISS social for pass information and more beginning on Tuesday Dec. 26. 73, Frank, KA3HDO

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Re: m^2 436 cp antenna
by Paul Andrews 25 Dec '23

25 Dec '23

Nick, To loosen the shorting bar set screws, carefully heat the shorting bar with a propane torch. As the aluminum expands, the set screw will free. Use an allen wrench to maintain mild torque on the set screw as the shorting block is heated. Good luck. 73 - Paul - W2HRO On Mon, Dec 25, 2023 at 8:09 AM nick via AMSAT-BB <amsat-bb(a)amsat.org> wrote: > I am trying to refurbish my M^2 antenna and the se screws on the shorting > bar are frozen. Any suggestions how to free up the set screws? > > > > > > > > > > > > > > nick > > > > Cell 337 258 2527 > > > > *Helping UL become a world Class Engineering and Educational School* > > *Disagree I Learn* > > > > > > ----------------------------------------------------------- > > Sent via AMSAT-BB(a)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. > Acceptable Use and Privacy Policies available at > https://www.amsat.org/about-amsat/ > > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/[email protected] > To unsubscribe send an email to amsat-bb-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org

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Re: m^2 436 cp antenna
by J. Hunt 25 Dec '23

25 Dec '23

Try using Liquid Wrench spray - it works very well with corroded / rusty fasteners. Thanks n 73,JamesKI5DQ. On Monday, December 25, 2023 at 08:25:19 AM CST, mikflathead--- via AMSAT-BB <amsat-bb(a)amsat.org> wrote: When all else fails drill out the set screw and drill and tap the other side or tap the side you drilled out with the next larger size. A little heat may expand the aluminum? Good luck and Merry Christmas On Monday, December 25, 2023 at 09:05:17 AM EST, Tim Campbell via AMSAT-BB <amsat-bb(a)amsat.org> wrote: I will second Joe's suggestion. It's the best penetrant I have ever used. If you can't get them loose after soaking them for a while, you can try the appropriate size LEFT hand drill bit. Sometimes the left hand bit will spin the set screws out. Drill carefully or you will quickly mess up the aluminum threads. Worst case scenario is carefully cut them off the elements and install new shorting bar kits as part of the refurbishment. M2 sells them as replacement parts. Merry Christmas es 73,Tim KB2MFS | | Virus-free.www.avast.com | On Mon, Dec 25, 2023 at 7:16 AM Joseph B. Fitzgerald via AMSAT-BB <amsat-bb(a)amsat.org> wrote: https://www.kroil.com/ de KM1P Joe ----------------------------------------------------------- Sent via AMSAT-BB(a)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. Acceptable Use and Privacy Policies available at https://www.amsat.org/about-amsat/ View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/[email protected] To unsubscribe send an email to amsat-bb-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org ----------------------------------------------------------- Sent via AMSAT-BB(a)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. Acceptable Use and Privacy Policies available at https://www.amsat.org/about-amsat/ View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/[email protected] To unsubscribe send an email to amsat-bb-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org ----------------------------------------------------------- Sent via AMSAT-BB(a)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. Acceptable Use and Privacy Policies available at https://www.amsat.org/about-amsat/ View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/[email protected] To unsubscribe send an email to amsat-bb-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org

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Re: m^2 436 cp antenna
by mikflathead＠aol.com 25 Dec '23

25 Dec '23

When all else fails drill out the set screw and drill and tap the other side or tap the side you drilled out with the next larger size. A little heat may expand the aluminum? Good luck and Merry Christmas On Monday, December 25, 2023 at 09:05:17 AM EST, Tim Campbell via AMSAT-BB <amsat-bb(a)amsat.org> wrote: I will second Joe's suggestion. It's the best penetrant I have ever used. If you can't get them loose after soaking them for a while, you can try the appropriate size LEFT hand drill bit. Sometimes the left hand bit will spin the set screws out. Drill carefully or you will quickly mess up the aluminum threads. Worst case scenario is carefully cut them off the elements and install new shorting bar kits as part of the refurbishment. M2 sells them as replacement parts. Merry Christmas es 73,Tim KB2MFS | | Virus-free.www.avast.com | On Mon, Dec 25, 2023 at 7:16 AM Joseph B. Fitzgerald via AMSAT-BB <amsat-bb(a)amsat.org> wrote: https://www.kroil.com/ de KM1P Joe ----------------------------------------------------------- Sent via AMSAT-BB(a)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. Acceptable Use and Privacy Policies available at https://www.amsat.org/about-amsat/ View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/[email protected] To unsubscribe send an email to amsat-bb-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org ----------------------------------------------------------- Sent via AMSAT-BB(a)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. Acceptable Use and Privacy Policies available at https://www.amsat.org/about-amsat/ View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/[email protected] To unsubscribe send an email to amsat-bb-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org

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Re: m^2 436 cp antenna
by Tim Campbell 25 Dec '23

25 Dec '23

I will second Joe's suggestion. It's the best penetrant I have ever used. If you can't get them loose after soaking them for a while, you can try the appropriate size LEFT hand drill bit. Sometimes the left hand bit will spin the set screws out. Drill carefully or you will quickly mess up the aluminum threads. Worst case scenario is carefully cut them off the elements and install new shorting bar kits as part of the refurbishment. M2 sells them as replacement parts. Merry Christmas es 73, Tim KB2MFS <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> Virus-free.www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Mon, Dec 25, 2023 at 7:16 AM Joseph B. Fitzgerald via AMSAT-BB < amsat-bb(a)amsat.org> wrote: > https://www.kroil.com/ > > de KM1P Joe > > > ----------------------------------------------------------- > > Sent via AMSAT-BB(a)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. > Acceptable Use and Privacy Policies available at > https://www.amsat.org/about-amsat/ > > View archives of this mailing list at > https://mailman.amsat.org/hyperkitty/list/[email protected] > To unsubscribe send an email to amsat-bb-leave(a)amsat.org > Manage all of your AMSAT-NA mailing list preferences at > https://mailman.amsat.org >

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Re: m^2 436 cp antenna
by Joseph B. Fitzgerald 25 Dec '23

25 Dec '23

https://www.kroil.com/ de KM1P Joe

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m^2 436 cp antenna
by nick 25 Dec '23

25 Dec '23

I am trying to refurbish my M^2 antenna and the se screws on the shorting bar are frozen. Any suggestions how to free up the set screws? nick Cell 337 258 2527 Helping UL become a world Class Engineering and Educational School Disagree I Learn

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