Shortwave listening and everything radio including reviews, broadcasting, ham radio, field operation, DXing, maker kits, travel, emergency gear, events, and more
Many thanks to SWLing Post contributor, Mike Hansgen, who shares the following article by Paul Litwinovich at WSHU:
In this article I’ll look at two things that, unless you are a serious ham operator or an absolute radio geek, you probably are unfamiliar with.
First, we will take a look at a very rare phenomenon first noted by radio listeners back in 1933. It generated several theories, but the correct one was only verified experimentally in recent times.
Second, we will look at a government-funded project that, while built for other purposes, was used to confirm the phenomenon 75 years later.
The Luxembourg Effect was first documented by electrical engineer and professor Bernard Tellegen. The professor is also credited with the invention of the tetrode vacuum tube. My past article, A Radio for the Roaring Twenties, features one of the first radios to use the tube.
One night, Mr. Tellegen was in the Netherlands, listening to a station transmitting from Beromunster, Switzerland, on 652 kHz. In the background of the Swiss signal, he could hear the audio of Radio Luxembourg, which normally broadcast on 252 kHz. He was far enough away from each station that neither station’s signal would have been strong enough to overload his receiver. The two signals seemed to be mixing somehow, but by what means?[…]
Many thanks to SWLing Post contributor, Mike Hansgen, who notes that Ken Burns’ film, Empire of the Air is now streaming on YouTube. This impressive documentary was originally broadcast in 1992. The following is a summary taken from the Empire of the Air website:
For 50 years radio dominated the airwaves and the American consciousness as the first “mass medium.” In Empire of the Air: The Men Who Made Radio, Ken Burns examines the lives of three extraordinary men who shared the primary responsibility for this invention and its early success, and whose genius, friendship, rivalry and enmity interacted in tragic ways. This is the story of Lee de Forest, a clergyman’s flamboyant son, who invented the audion tube; Edwin Howard Armstrong, a brilliant, withdrawn inventor who pioneered FM technology; and David Sarnoff, a hard-driving Russian immigrant who created the most powerful communications company on earth.
Against the backdrop of radio’s “Golden Age,” Empire of the Air relates the history of radio through archival photographs, newsreels of the period and interviews with such well-known radio personalities as Garrison Keillor, the late sports commentator Red Barber, radio dramatist Norman Corwin and the late broadcast historian Erik Barnouw.
As with many videos on YouTube, this film could be removed at any time without warning. I suggest watching this soon:
Many thanks to SWLing Post contributor, Mike Hansgen, who shares this news/media from the BBC World Service:
Could broadcasting school lessons solve Africa’s education crisis? The BBC spoke to a pupil in the Democratic Republic of Congo who is learning through the radio.
At Ears To Our World we’ve long appreciated the power of radio to spread information in rural and remote parts of the world: it’s effective, accessible and essentially free to the listener. Viva la radio!
As Low-Power Local Radio Rises, Tiny Voices Become a Collective Shout
SEATTLE — A knowledge of geography is essential if you are running a tiny, 100-watt radio station. Hills are bad, for example, as are tall buildings. Salt water, though, which lies at this city’s doorstep, can boost a radio signal for miles, like a skipped rock.
For a low-power FM radio station, anything measurable in miles is good.
But on a recent Thursday night, one station, KBFG, was struggling to even get on the air. The station’s signal, audible since November in an area measurable in square blocks, had flatlined. The Ballard High School basketball team was about to take the court and the live play-by-play was in doubt.
“We’re bootstrapping it,” said Eric Muhs, a physics and astronomy teacher. Headphones were slung around his neck, and a mop of unruly gray hair came further undone as he leaned into his laptop trying to fix a software glitch. But Mr. Muhs, 60, one of KBFG’s founders, admitted that the stakes for failure were relatively low. “Almost nobody knows that we exist,” he said.
Low-power nonprofit FM stations are the still, small voices of media. They whisper out from basements and attics, and from miniscule studios and on-the-fly live broadcasts like KBFG’s. They have traditionally been rural and often run by churches; many date to the early 2000s, when the first surge of federal licenses were issued.
But in the last year, a diverse new wave of stations has arrived in urban America, cranking up in cities from Miami to the Twin Cities in Minnesota, and especially here in the Northwest, where six community stations began to broadcast in Seattle.[…]
Many thanks to SWLing Post contributor, Michael Guerin, who shares this article at CNN by Dr. Don Lincoln, a senior physicist at Fermilab and researcher at the Large Hadron Collider:
Earth dodges a cosmic bullet — for now
Solar flares and related phenomena could cause tremendous damage to the Earth’s electric grids, writes Don Lincoln Read the full story
(CNN) Mother Nature has had a hectic past couple of weeks of hurricanes, an earthquake, wildfires and flooding. But while our attention has been turned to these humanitarian crises, Earth ducked a cosmic bullet the likes of which could have crippled human technological civilization.
Over the last week or so, the sun has experienced a series of solar flares, including the most energetic one in a decade. A solar flare occurs when magnetic energy in the vicinity of a sunspot is released, resulting in a bright spot on the sun that takes place over a time scale of perhaps 10 minutes — or even less.
[…]While solar flares can interfere with satellites, an even more dangerous phenomenon is called a coronal mass ejection (or CME). CMEs often accompany a flare and occur when some of the sun’s highly ionized material is ejected into space. Because a CME consists of matter and not the electromagnetic radiation of a flare, it can take a day or even more to travel from the sun to the Earth. Indeed, last week’s flares were accompanied by a CME, but it didn’t hit the Earth with its full fury.
If a CME happens to be aimed directly at Earth, the ionized particles can slam into the magnetic field that surrounds the Earth and distort its shape, a process called a geomagnetic storm. That’s when things can get dangerous. Moving magnetic fields can induce electrical currents on the Earth’s surface and damage equipment.
In 1989, a CME hit the Earth and knocked out power in Quebec and the northeast United States for nine hours. And in 1859, an enormous CME hit the Earth. Called the Carrington Event, after Richard Carrington, who observed and recorded it, this geomagnetic storm caused telegraph pylons and railroad rails to spark, shocked telegraph operators and was responsible for auroras visible at least as far south as Havana, Cuba, with some claims of auroras being observed near the Earth’s equator.
[…]A report by Lloyd’s of London in 2013 estimated that the damage to the US grid from a repeat of the Carrington Event would be in the range of $0.6-$2.3 trillion dollars and would require four to 10 years to repair.
“The total U.S. population at risk of extended power outage from a Carrington-level storm is between 20-40 million, with durations of 16 days to 1-2 years,” the Lloyd’s report said.[…]
Many thanks as well to Mike Hansgen (K8RAT) who also shares the latest space weather news from Tamitha Skov, reiterating how fortunate we were to miss this last barrage from our local star:
One additional note: I’m currently in the process of writing a lengthy article about how to protect your gear from an EMP (Electromagnetic Pulse) emanating from an event like this. In the past two weeks, I’ve had an uptick in inquiries about this, so I thought it best to consult an expert and produce a post. I’ll hopefully have this article published within a week or so. I’ll post it with the tag: EMP.
The AR-88 was a valve-based shortwave general coverage communications receiver, developed and built by the Radio Corporation of America (RCA) in the early 1940s. Although the receiver was initially intended as the successor to the AR-77 amateur receiver, the outbreak of WWII made it evolve into a professional high-end military-grade receiver for which cost was no object.
The AR-88 is a 14-valve (tube) receiver, which covers a frequency range of 535 kHz to 32 MHz. Unlike the National HRO receiver, which had pluggable coil packs for each frequency band, the AR-88 uses a six-position band selector. A special version of the receiver, the AR-88LF, was suitable for LF and MF, covering 70 to 550 kHz (continuously) and 1.5 to 30 MHz (continuously).
I’m sure I actually have a close up of this receiver somewhere. It also appears to be an RCA AR-88 based on dial and control configuration, though I certainly could be wrong.
Do any SWLing Post readers have an AR-88? Please comment!
The face which inspired hope to a nation during the dark days of WW2 will once again light up the White Cliffs of Dover.
Forces Sweetheart Vera Lynn turns 100 today with a special tribute to the singer and the song she made famous…They’ll be Bluebirds Over The White Cliffs of Dover.
(Source: The Mirror)
A 150ft image of the inspiring Vera is being projected onto the iconic white cliffs in Kent as she becomes the first centurion to release an album! [Continue reading…]
Mike adds:
“It is March 20, the 100th birthday of the wonderful Forces Sweetheart. Remember her boys who flew the Spitfires and the Lancasters. Remember her boys at Arnhem.
Remember them all.”
Mike knows I’m a WWII buff and also a fan of Dame Lynn.
