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ARRL Has Another New CEO |
Posted by: VE3WI Dave - 2020-08-27, 20:57:02 - Forum: Opinion
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The ARRL Board of Directors has elected David Minster, NA2AA, as ARRL’s new Chief Executive Officer. He replaces an interim CEO who has been at the helm since January when the BOD turfed Howard Michel, WB2ITX.
http://www.arrl.org/news/board-of-direct...ster-na2aa
Good luck to you David. Hopefully you can lead the ARRL out of the pit of infighting and strife that has characterized leadership and member relations in the last few years.
73
Dave, VE3WI
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Zoom Saturday's different topic each week |
Posted by: Guest - 2020-08-23, 19:40:32 - Forum: Upcoming Events
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There is a zoom program with different topics each Saturday morning at 10:am Held by the Manitoulin Island club, but any one wishing to join is welcome. To get on the list first download the zoom Icon, then set your calendar for Sat Aug 29th 10 am -12pm event is meeting the place Zoom .To get your name on the list you have to add your name and call sign then send a message to ve3ajb@vianet.ca On Saturday morning you will have a message in your mail box it will let you know what to do next. the topic this coming Saturday Aug 29th will be about satellite tracking. we would enjoy you being there, you don't have to stay in there is you don't want too, check it out. thanks ve3mio (Maureen) mnight@bell.net
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Grasswire Antenna |
Posted by: VA3KOT John - 2020-08-03, 12:34:50 - Forum: Antennas
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The conventional wisdom is: "get your antenna up as high as you can". But, as Mike Toia K3MT has demonstrated and published, a wire antenna laid directly on the ground also works. Mike calls his antenna a "Grasswire". Critics dismissed the idea as ridiculous. Ground losses will completely wipe out your signal, they say. But anyone who has tried a Grasswire (many, including myself) knows, it does work, with some limitations. Here is how it works.
The signal in the antenna will induce a reflection in the ground. The reflected wave in the ground exactly cancels the signal in the antenna - up to about a half-wavelength. Because the reflected wave travels more slowly than the above ground signal, the phase relationship between the two changes with antenna length. If the antenna is at least a full wavelength long, less of the signal is cancelled by the reflected wave. At some point, the phase relationship results in zero cancellation and the signal is radiated as though no ground is present (see attached diagram).
K3MT measured the current in the antenna wire along its length and determined that the current (and therefore the radiated power; remember P=i^2R) diminishes rapidly and that any antenna over one wavelength long is unnecessary. In contrast, the US Marine Corps used very long wires (5 wavelengths) for field expedient antennas in Vietnam, but they kept the wire at least 1 metre above ground, thereby reducing ground losses.
A very long wire (aka Wave Antenna) radiates a vertically polarized signal off its ends. At a certain angle between the incident wave and the ground (known as Brewster's Angle) the signal is reflected instead of being refracted into the ground. You can observe Brewster's Angle by going to the Huron coast in the evening and watching the sun get lower in the sky. At a certain height above the horizon the sunlight will reflect brightly off the surface of the lake. This is the effect that takes place with a Grasswire Antenna.
I have experimented with Grasswires for several years with limited success. My devotion to QRP ended with the poor propagation conditions accompanying the latest solar minimum. According to EZNEC, a Grasswire will result in a gain of about -12dB. A 5 watt signal will be attenuated down to milliwatt level but a 100 watt signal into a Grasswire will still radiate 12.5 watts.
So why use a lossy antenna? Stealth! A Grasswire is invisible. Lay it down anywhere and operate. It can be deployed in seconds and you're on the air. And fun. I enjoy the experimental side of ham radio.
Here are my results from today's test (interrupted by rain before I could get a QSO so I tried WSPR):
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United Nations Amateur Radio Club (4U1UN) |
Posted by: Tom VA3TS - 2020-07-31, 10:13:43 - Forum: Antennas
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https://www.facebook.com/United-Nations-Amateur-Radio-Club-4U1UN-169357566427247/
Greetings from UNARC/4U1UN. As most are aware, UNHQ has been shut down for some time due to COVID-19. As a result, basic maintenance of equipment has been postponed until the building is reopened to staff. The Secretary General has implemented a multi-phased approach based on state and federal guidelines. As such, we hope to regain access in October or November. It's at that time that maintenance activities will be scheduled with the appropriate departments in order to address pressing equipment failures. This includes repair to our Acom amplifier control module as well as the beacon antenna.
On other news, I've been testing and evaluating a Flex Radio Systems 6600M which was kindly loaned to us by our friends at Flex Radio. The Flex SDR system has proven more than capable of performing in our constrained operating environment, and is something as current club president, hope to implement into our station as soon as possible. Many thanks go to Flex Radio, especially, Matt Youngblood for his generosity and willingness to work with the United Nations Amateur Radio Club 4U1UN.
I'll try to update you with more news as it's made available to me by senior management and our administration.
Until then, be safe. Be well.
73,
James K2QI
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Amateur Radio on the Moon |
Posted by: VE3WI Dave - 2020-07-13, 20:05:42 - Forum: Opinion
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Found this on the ARRL website:
73, Dave VE3WI
AMSAT-DL Submits Lunar Lander Proposal to European Space Agency
07/13/2020
Germany’s amateur satellite organization AMSAT-DL has submitted a comprehensive proposal to the European Space Agency (ESA) for its Lunar Amateur Radio Transponder (LunART) lunar lander — a communications platform on the Large European Lander to support communication and payload experiments. AMSAT-DL’s Peter Gülzow, DB2OS, and Matthias Bopp, DD1US, say that a LunART (called “LunaART” in the AMSAT-DL proposal) would support direct communication with Earth via amateur radio, support university and student payloads and offer direct access to their experiments, and expand the reach of radio science. It could also provide backup communication capability and capacity during an emergency, or when the ESA network is busy.
The comprehensive radio platform would use the European frequency protocol of 2.4 GHz up and 10.45 GHz down (approximately 100 W), pioneered in the QO-100 satellite, the first geosynchronous amateur radio payload. The platform would also include a VHF/UHF transponder. AMSAT-DL would develop and build the necessary hardware and software and provide ground station support via the 20-meter dish at AMSAT-DL headquarters in Bochum, Germany. They envision developing a smaller ground station with an approximately 1-meter dish to support groups, including schools and universities. Low-power beacons would transmit on various frequencies from VHF (145 MHz) through SHF (up to 24 GHz or even 47 GHz), AMSAT-DL’s proposal says.
“This transponder would also be an ideal platform to develop new transmission schemes with novel modulation and coding techniques optimized for long-distance communications with the corresponding high latency (long delays),” AMSAT-DL said. “This would provide essential knowledge in preparation of a future Mars mission.” In addition, LunART could include the capability to transmit still or slow-scan television images and video to schools “from cameras attached to the lander monitoring the moon surface and perhaps the Earth in the background [which] would be ideal stimuli for getting school kids and STEM organizations further interested in space.”
The proposal is on open access at the ESA website and is now being evaluated. AMSAT-DL’s LunART follows the Lunar Amateur Radio Interaction Experiment (LARIE) proposal from Andy Thomas, G0SFJ. Both refer to weak signal modes and suggest the same frequency bands. Thomas said he welcomes LunART as a well-developed proposal and hopes ESA will support it as well. — Thanks to Southgate Amateur Radio News, AMSAT-DL, and ESA
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Cabot Head Future Uncertain |
Posted by: VE3WI Dave - 2020-07-13, 08:55:04 - Forum: Upcoming Events
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Searching for info on Cabot Head, I found this:
https://www.owensoundsuntimes.com/news/l...lar-refurb
I particularly like the bit about the folks who built houses at Dyers Bay along the road and now are complaining about the traffic (duh!)
Future looks uncertain to say the least. Road needs expensive repair & lighthouse has serious water damage. Municipality obviously wants the Feds to pay it all. It would be a shame to lose it after DFO just spent 1.3 M$ of our tax money to "make it safe".
I enjoyed doing ILLW up there, be a real shame if we can't operate there any more.
73
Dave, VE3WI
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