Author Archives: Thomas

Radio Waves: Quantum Sensors, Sinking Mi Amigo, Submarine Radio Network, and Video Games Over The Air

Radio Waves:  Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’sRadio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Kim Elliott and Dennis Dura for the following tips:


Scientists create quantum sensor that covers entire radio frequency spectrum (Phys.org)

A quantum sensor could give Soldiers a way to detect communication signals over the entire radio frequency spectrum, from 0 to 100 GHz, said researchers from the Army.

Such wide spectral coverage by a single antenna is impossible with a traditional receiver system, and would require multiple systems of individual antennas, amplifiers and other components.

In 2018, Army scientists were the first in the world to create a quantum receiver that uses highly excited, super-sensitive atoms—known as Rydberg atoms—to detect communications signals, said David Meyer, a scientist at the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory. The researchers calculated the receiver’s channel capacity, or rate of data transmission, based on fundamental principles, and then achieved that performance experimentally in their lab—improving on other groups’ results by orders of magnitude, Meyer said.

“These new sensors can be very small and virtually undetectable, giving Soldiers a disruptive advantage,” Meyer said. “Rydberg-atom based sensors have only recently been considered for general electric field sensing applications, including as a communications receiver. While Rydberg atoms are known to be broadly sensitive, a quantitative description of the sensitivity over the entire operational range has never been done.”[]

Forty years ago today Sheerness lifeboat crew rescued Radio Caroline DJs from the sinking Mi Amigo (Kent Online)

It was the original ‘ship that rocked.’ But 40 years ago today (Thursday)the Mi Amigo, home to original pop pirates Radio Caroline, finally disappeared beneath the waves in a violent force 10 storm.

In a daring rescue which lasted 12 hours in appalling weather, the crew of the Sheerness lifeboat saved the lives of everyone onboard – including the ship’s canary.

Leading the operation was colourful RNLI coxswain Charlie Bowry, who was later presented with the Institute’s coveted silver medal.

It was during the day that the radio station’s 60-year-old ship started dragging its anchor and drifted 10 nautical miles onto the Long Sand sandbank off Southend.

As the tide rose, the ship started to float free. But the bottom of the boat began being buffeted on the seabed with such a force the steel plates sprung a leak and water gushed into the engine room.

When the bilge pumps couldn’t cope, the three British DJs and a Dutch engineer called the Coastguard who dispatched Sheerness lifeboat the Helen Turnbull.[]

The Radio Network that Allowed Communication with Submarines (Interesting Engineering)

Communicating with covert fleets during WWII required some special equipment.

What do you do when you need to communicate with a crew of 50 sailors submerged in a submarine in an undisclosed location across the world’s oceans? That was a difficult question to answer for Navy leaders in WWII.

Radio waves don’t easily travel through saltwater, which meant that getting active communication with a submarine crew meant making the submarine surface an antenna. This was the obvious solution, but it made a previously covert submarine now a visible target.

[…]Engineers tasked with finding a more covert solution soon discovered that radio waves with low frequencies, around 10 kHz, could penetrate saltwater to depths up to around 20 meters. They realized that if the transponders on submarines were switched to these frequency ranges, then they communicate with leadership on land.

The problem with this idea was that creating and broadcasting these low-frequency radio waves required massive antennas. Essentially, the lower the frequency of a radio wave, the longer and larger the antenna is required to be.[]

You Could Download Video Games From the Radio in the 1980s (Interesting Engineering)

Certain radio programs broadcast the raw data to video games for viewers to download.

[…]In 1977, the world’s first microprocessor-driven PCs were released. These were the Apple II, the Commodore PET, and the TRS-80. All these machines had one thing in common – they used audio cassettes for storage.

Hard drives at the time were still quite expensive, and everyone at the time had access to cheap audio cassettes. Early computer designers actually flaunted cassette storage as it aided in the early adoption of personal computers. As PCs became more common, so to did the emergence of their use as video game machines.

As the 1980s rolled around, engineers at the Nederlandse Omroep Stichting, NOS, a Dutch broadcasting organization, realized something incredible. Since computer programs and video games were stored on audio cassettes, it meant that their data could be transmitted with ease over the radio. They started taking programs and video games and setting up broadcasts where people could “download” games onto their own personal computers.

The audio that was transmitted would’ve sounded reminiscent of a dial-up modem booting up.

[…]NOS started a radio program specifically for transmitting gaming data called “Hobbyscoop,” and it became incredibly popular. The company even created a standard cassette format called BASICODE to ensure computer compatibility.

Eventually, transmitting games through computers became so popular that radio shows popped up all around the world. A Yugoslovik station called “Ventilator 202” broadcasted 150 programs between 1983 and 1986. As the practice evolved, it became less of a novelty and rather a practical way for people to share calculation programs, educational tools, encyclopedias, and even flight simulators.[]


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“Sri Lanka turning ex-Voice of America relay station into COVID-19 hospital”

Google Earth view

(Source: Economy Next)

ECONOMYNEXT – Sri Lanka will turn the building of a former Voice of America relay station into a COVID-19 hospital, as part of efforts to accommodate an increase in patients, a high level task force that drive Coronavirus control activities in the country said.

Sri Lanka has designated 18 hospitals to accept COVID-19 patients, but most of the confirmed patients are treated at the main infectious disease hospital in Colombo.

Mulleriyawa hospital, which is close to the IDH has also been turned into a COVID-19 treatment centre.

Sri Lanka is turning decommissioned Voice of America facilities into a COVID-19 treatment centre with the help of the military, a statement from the anti-COVID-19 task force quoted, Director General of Health Service Anil Jasinghe as saying.

The Voice of America relay station in Iranawila was built under heavy opposition from the Catholic Church. The VOA paid rent for the land and handed over facilities free of charge to the government.

VOA also handed over its old transmitters in Ekala and the land to the government when the new relay stations was built.[…]

Click here to read the full article.

Ipsos survey explores Coronavirus impact on radio usage

(Source: Inside Radio via Dennis Dura)

Here’s How Coronavirus Is Impacting Work Habits And Radio Usage.

Scores of companies across the country are encouraging their employees to work from home to help limit the spread of the coronavirus outbreak. How this is changing American work habits and their usage of AM/FM radio is the subject of a freshly fielded study from Ipsos.

Commissioned by Cumulus Media/Westwood One, the national study of 1,027 persons 18+ was conducted from March 13 -15 “While the number of businesses, venues, and locations that have closed or curtailed visitation has grown sharply even since this study was fielded just two days ago, this data serves to quantify the state of the American workforce during a period in time,” Cumulus/Westwood One Chief Insights Officer Pierre Bouvard says in a post on the “Everyone’s Listening” blog.

[…]Importantly for radio, nearly one in five (18%) heavy AM/FM radio listeners, defined as those who listen to more than 5 hours a week, say they will listen even more to broadcast radio due to the coronavirus outbreak, while 79% said about the same and only 4% indicated less.

Additionally, 20% of heavy AM/FM radio listeners say they will be listening more to news reports on AM/FM radio. “The crisis has also turned many into news fanatics,” Bouvard says. “Nearly one-third say they will be consuming more news online and news on TV.”[…]

Click here to read the full article.

AirSpy YouLoop passive magnetic loop antenna now shipping

Many thanks to SWLing Post contributor, Michael Agner (KA3JJZ), who notes that AirSpy  now has the YouLoop passive mag loop antenna posted on their retail websites.  You can grab one for $30 – $35 US, depending on your location. That’s a fantastic deal in my book.

Click here to check out the YouLoop at Airspy.com.

Click here to check out the YouLoop at Airspy.US ($29.95 + shipping).

Click here to search for other AirSpy distributors.

Note that the YouLoop only works well with high dynamic range SDRs and receivers like the AirSpy HF+ Discovery.

Smithsonian Open Access: Take a deep radio nostalgia dive!

“Radio owned by Herman and Minnie Roundtree” (Source: Smithsonian Open Access)

Many thanks to SWLing Post contributor, Balázs Kovács, who shares the following announcement:

[Check out the] Smithsonian Open Access, where you can download, share, and reuse millions of the Smithsonian’s images—right now, without asking. With new platforms and tools, you have easier access to nearly 3 million 2D and 3D digital items from our collections—with many more to come. This includes images and data from across the Smithsonian’s 19 museums, nine research centers, libraries, archives, and the National Zoo.

As Balázs points out, there are hundreds of radio photos in the archive.

What a treasure trove! Since many of us are sheltering at home, it’s the perfect time to take a deep dive into the SOA archive!  Thank you for sharing!