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This Week in Amateur Radio News for Wednesday 11 January 2017
TWIAR News Feed
/////////////////////////////////////////// via HACKADAY: Did a Russian Physicist Invent Radio? Posted: 11 Jan 2017 03:45 PM PST http://ift.tt/2iaxEUh It is said that “success has many fathers, but failure is an orphan.” Given the world-changing success of radio in the late 19th and early 20th centuries, it’s no wonder that so many scientists, physicists, and engineers have been credited with its invention. The fact that electromagnetic radiation is a natural phenomenon that no one can reasonably claim to have invented sometimes seems lost in the shuffle to claim the prize. But it was exactly through the study of natural phenomena that one of the earliest pioneers in radio research came to have a reasonable claim to at least be the inventor of the radio receiver, well before anyone had learned how to reliably produce electromagnetic waves. This is the story of how a Russian physicist harnessed the power of lightning and became one of the many fathers of radio. /////////////////////////////////////////// Nevada ARES Standing Down as Flood Threat Abates Posted: 11 Jan 2017 03:35 PM PST http://ift.tt/2ijKOhO Amateur Radio Emergency Service (ARES®) volunteers and emergency operations centers (EOCs) in Nevada are now standing down as the threat of additional widespread flooding damage diminishes. Over the weekend, ARES members in Nevada stood ready to support the disaster response effort. Recent heavy rainfall, sparked by a weather system called the Pineapple Express, caused flooding along rivers and forced evacuations in some areas of Nevada and neighboring California. The flooding prompted Nevada Gov. Brian Sandoval to declare a state of emergency. In Reno the Truckee River crested above 12 feet on January 9, and at 19.5 feet in Sparks. The river is now below flood stage and, despite a forecast of more rain and snow, was expected to remain so. Carrying moisture-laden warm air from Hawaii, the Pineapple Express “atmospheric river” flowing across a narrow band of the Sierra Nevadas brought snow followed by rainfall of up to 15 inches to northern Nevada and California. While the rainfall may have broken the back of the region’s lengthy drought, it caused the snowpack in the Sierras to melt, initiating avalanches and mudslides, washing out roadways, and causing heavy flooding. /////////////////////////////////////////// via HACKADAY: Anatomy Of A Digital Broadcast Radio System Posted: 11 Jan 2017 03:35 PM PST http://ift.tt/2jawiqS What does a Hackaday writer do when a couple of days after Christmas she’s having a beer or two with a long-term friend from her university days who’s made a career in the technical side of digital broadcasting? Pick his brains about the transmission scheme and write it all down of course, for behind the consumer’s shiny digital radio lies a wealth of interesting technology to try to squeeze the most from the available resources. In the UK, our digital broadcast radio uses a system called DAB, for Digital Audio Broadcasting. There are a variety of standards used around the world for digital radio, and it’s fair to say that DAB as one of the older ones is not necessarily the best in today’s marketplace. This aside there is still a lot to be learned from its transmission scheme, and from how some of its shortcomings were addressed in later standards. /////////////////////////////////////////// New Digital Modes Gain Traction for Moonbounce, but Occasionally Show Up on HF Posted: 11 Jan 2017 03:35 PM PST http://ift.tt/2jfHl21 In December, Joe Taylor, K1JT, released the latest version (1.7) of his WSJT-X software suite, designed to facilitate basic Amateur Radio communication using very weak signals (WSJT stands for “Weak Signal communication by K1JT”). Version 1.7 included the new modes MSK144 and QRA64, as well as ISCAT (ionospheric scatter). MSK144 and QRA64 (and QRA64A) are finding a home within the VHF Earth-Moon-Earth (EME, or moonbounce) and meteor-scatter communities, but QRA64A signals also have turned up on 160 meters, which poses its own challenges to weak signals. “QRA64A QSOs are being made nightly on 160 meters, of all places, and QRA64 activity on 2-meter EME is becoming significant, especially on weekends,” Taylor remarked in a January 9 update posted to the Moon-Net reflector, pointing out that QRA64 is decoding signals down to about –28 dB signal-to-noise. /////////////////////////////////////////// via HACKADAY: Pumping Up An Antenna From A Stream Of Sea Water Posted: 11 Jan 2017 04:00 PM PST http://ift.tt/2jxArIQ Our Hackaday readership represent a huge breadth of engineering experience and knowledge, and we get a significant number of our story tips from you. For instance, today we are indebted to [sonofthunderboanerges] for delivering us a tip in the comment stream of one of our posts, detailing an antenna created by coupling RF into a jet of sea water created with a pump. It’s a few years old so we’re presenting it as an object of interest rather than as a news story, but it remains a no less fascinating project for that. The antenna relies on the conductivity of sea water to view a jet of water as simply another conductor to which RF can be coupled. The jet is simply adjusted by altering the flow rate until it is a quarter wavelength long at the desired frequency, at which point it is a good analogue of a metal whip antenna. The RF is coupled at the base by a ferrite cored transformer that clips around the nozzle ejecting the water, and a bandwidth from 2MHz to 400MHz is claimed. If you work with RF you will probably wince at the sight of salt water coming near the RF connector, as we did. The advantage of the system is that it allows antennas of multiple frequencies to be created at very short notice and using very little space or weight when not in use. The creator of the antenna at the US Navy’s SPAWAR technology organization points to its obvious application on Navy warships. Whether or not the sailors are using these antennas now isn’t clear, but one thing’s for certain, the idea hasn’t gone away. Early last year Popular Mechanics reported on a similar project under way courtesy of Mitsubishi, in Japan. /////////////////////////////////////////// UK Regulator Ofcom No Longer Listing Unassigned Amateur Radio Call Signs Posted: 11 Jan 2017 03:35 PM PST http://ift.tt/2jfMhnE UK Telecommunications regulator Ofcom no longer issues lists of unassigned — or unallocated — Amateur Radio call signs. This practice ended last fall. Replying to an inquiry, Ofcom’s Julia Snape explained, “We do not hold a list of call signs that are available. Due to a system change, the assignment of call signs is now done using an algorithm rather than ‘grabbing’ from a list.” |
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