Tag Archives: OTH RADAR

Radio Waves: Who Will Pay, Ham Radio Culture, OTH Support, CarnationFM, Night of Nights, and 100 Years of Radio

Radio Waves:  Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Richard Cuff, Dennis Dura,
David Korchin, Roger Fitzharris, David Iurescia, and NT for the following tips:


In 1924, a magazine ran a contest: “Who is to pay for broadcasting and how?” A century later, we’re still asking the same question (NiemanLab)

Radio Broadcast received close to a thousand entries to its contest — but ultimately rejected them all.

After yet another day reading about audio industry layoffs and show cancellations, or listening to podcasts about layoffs and show cancellations, I sometimes wonder, “With all this great audio being given away for free, who did we think was supposed to pay for it all?”

I find some consolation in the fact that that question is more than a century old. In the spring of 1924, Radio Broadcast posed it in a contest called “Who is to Pay for Broadcasting and How?”The monthly trade magazine offered a prize of $500 (more than $9,000 in today’s dollars) for “a workable plan which shall take into account the problems in present radio broadcasting and propose a practical solution.”

The need for such a contest more than 100 years ago is revealing enough, but the reaction of the judges to the prize-winning plan turned out to be even more so — and it says a lot about why business models for audio production and broadcast remain a struggle. [Continue reading…]

The Rich History of Ham Radio Culture (The MIT Press Reader)

Drawing on a wealth of personal accounts found in magazines, newsletters, and trade journals, historian Kristen Haring provides an inside look at ham radio culture and its impact on hobbyists’ lives.

Every night thousands of men retreat to radio stations elaborately outfitted in suburban basements or tucked into closets of city apartments to talk to local friends or to strangers on the other side of the world. They communicate by speaking into a microphone, tapping out Morse code on a telegraph key, or typing at the keyboard of a teletypewriter. In the Internet age, instantaneous, long-distance, person-to-person communication seems ordinary. But amateur radio operators have been completing such contacts since the 1910s. The hobbyists often called “hams” initially turned to radio for technical challenges and thrills. As the original form of wireless technology became more reliable and commonplace in the 1930s, ham radio continued as a leisure activity. Hams formed a community through the same general practices of other social groups. They set conditions for membership, established rules of conduct, taught values, and developed a specialized vocabulary known only to insiders. What made hams’ culture different was its basis in technology. In her book “Ham Radio’s Technical Culture,” excerpted below, historian of science and technology Kristen Haring draws on a wealth of personal accounts found in radio magazines and newsletters and from technical manuals, trade journals, and government documents to illustrate how ham radio culture rippled through hobbyists’ lives. [Continue reading…]

CarnationFM: A Decentralized Radio Playing Songs With Encrypted Hidden Messages (Coin Desk)

CarnationFM emerged from EthBerlin 2024 and won the award for Best Social Impact.

Berlin, Germany: A music-focused radio FM which allows songs to act as a transport vessel for hidden messages has emerged from EthBerlin 2024. CarnationFM was created by five hackers and a mentor as a defensive, decentralized and encrypted communication tool enabling private messaging that safeguards anonymity.

The project, which won the award for the Best Social Impact at EthBerlin 2024, is focused on creating real world use cases factoring in privacy in the aftermath of the Alexey Perstev verdict. Alexey Perstev, one of the co-founders of Tornado Cash, was sentenced to 64 months in prison in May.

The verdict rattled the decentralized community because it suggested that a coder could be held responsible for everything that happens using that code. Perstev was found guilty because his open-source mixer Tornado cash allowed North Korea’s infamous Lazarus group to launder millions in crypto. [Continue reading…]

Nation’s last Morse code station comes back to life on annual ‘Night of Nights’ in Point Reyes (The Mercury News)

KPH, established in Point Reyes and Bolinas in 1913, will exchange messages with Morse code enthusiasts around the world

On July 12, 1999, the nation’s final message in Morse code was sent out to sea from a remote Bay Area radio station. The end of an era, the room’s mood was mournful. Grizzled old men wept.

“We wish you fair winds and following seas,” it said, offering a seafarers’ traditional farewell in a staccato stream of dots and dashes. And then the station went silent.

But every July 12, the golden age of maritime radio comes back to life. [Continue reading…]

Navy researchers ask Envisioneering to support over-the-horizon radar that relies on HF radio signals (Military Aerospace Electronics)

Over-the-horizon radar typically uses HF radio signals at frequencies between 2 and 30 MHz to reach beyond the horizon in open-ocean areas.

WASHINGTON – U.S. Navy researchers needed to help develop a new prototype High Frequency (HF) over the horizon (OTH) radar system. They found a solution from Envisioneering Inc. in Alexandria, Va.

Officials of the Naval Research Laboratory (NRL) in Washington announced a $45.4 million contract to Envisioneering Inc. on Monday for design, development and integration of a mobile over-the-horizon radar (MOTHR).

Over-the-horizon radar typically uses HF radio signals at frequencies between 2 and 30 MHz to reach beyond the horizon in open-ocean areas. HF signals bounce off the ionosphere to achieve long distances and operate beyond the curvature of the Earth.

Envisioneering will work alongside the NRL research team to support key areas such as refinement of system requirements; system and subsystem design; mechanical analysis; specifying and procuring long-lead items; integration; testing; and signal processing. [Continue reading…]

100 Years of 100 Things: Radio (WNYC)

Continuing our centennial series 100 Years of 100 Things, Matthew Barton, curator of recorded sound at the Library of Congress, walks us through the history of radio.

100 Years of 100 Things is part of WNYC’s centennial celebration. Each week, we’ll take listeners through a century’s worth of history of things that shape our politics, our lives and our world. Topics will include everything from immigration policy to political conventions, American capitalism to American socialism, the Jersey Shore to the Catskills, baseball to ice cream.

Click hee to listen via WNYC.


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Radio Waves: New Massive Over-The-Horizon Radar, Evolution of Receivers, Tour of Eisenhower’s Air Force One, and ABC on Cricket in 1930s

Radio Waves:  Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!


US Begins Installing ‘Mighty’ Over-The-Horizon Radar In Palau That Can Detect Objects Thousands of KMs Away! (The EurAsian Times)

The United States has begun work on the deployment of a new long-range over-the-horizon radar system for the United States Air Force, which will be placed on the Pacific island of Palau.

The sensor station, known as the Tactical Mobile Over-the-Horizon Radar, or TACMOR, will be set up on the highly strategic island of Palau. The sensor station intends to improve the situational awareness of US and allied forces operating in the region in the air and maritime domain.

The Department of Defense announced on December 28 that it had granted Gilbane’s Federal business a $118.4 million contract to develop the structural foundation of a new US Air Force radar station to be built in the Republic of Palau.

Gilbane Federal will build reinforced concrete pads and other foundational components as part of the firm-fixed-price contract to set up the Tactical Mobile Over-the-Horizon Radar system, the Department of Defense said.

The Naval Facilities Engineering Systems Command Pacific acts as the contracting activity for what is known as the TACMOR infrastructure project. The work is anticipated to be finished by June 2026. [Continue reading…]

The Evolution of Radio Receivers (Euro Scientist)

Radio receiver is one such gadget that people have been using for many generations. After the invention of radio communication by Guglielmo Marconi in 1895, the first radio receiver was also invented by Marconi. A radio receiver is an electronic device that can only receive radio signals and can convert the radio signals to audio and sound. A radio receiver can receive radio signals of various frequencies by tuning to a particular frequency. These frequencies are of two types – Amplitude Modulation (AM) and Frequency Modulation (FM). A radio receiver capable of receiving any analog audio on AM/FM frequency is called analog radio receiver and for many years people were using analog radio receivers.

Since the invention of analog radio by Marconi in 1895, many companies started manufacturing radio receivers. First came the De Forest RJ6 in 1916, and later many analog radio receivers like Sony TR-63 (1957), and H.H. Scott 350 (1961) came in the market, and they were the first analog radio receivers of that kind. After the emergence of digital electronics and digital radio transmission, digital radio receivers started to capture the market – receivers capable of receiving Digital Audio Broadcasting (DAB) – digital radio transmission. In 2003, Pure launched the PocketDAB 1000 and It was the world’s first pocket digital radio capable of playing DAB radio stations. However, radio receivers became diversifying when internet technology was implemented in them, which made it possible for the companies to introduce internet radio receivers. An internet radio receiver can be either an app of a computer or can be a standalone receiver, connected to the internet to receive internet radio stations. Kerbango internet radio receiver from 3com was the first standalone internet radio receiver of 21th century. This change in the technology of radio receivers even went beyond internet radio – after the arrival of Software Defined Radio (SDR).

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Looking at HF OTH RADAR

Many thanks to SWLing Post contributor, Trevor, who shares this link to a blog post from Daniel Estevez describing the characteristics of HF OTH RADAR:

Most amateur operators are familiar with over-the-horizon radars in the HF bands. They sometimes pop up in the Amateur bands, rendering several tens of kilohertzs unusable. Inspired by Balint Seeber’s talk in GRCon16, I’ve decided to learn more about radars. Here I look at a typical OTH radar, presumably of Russian origin. It was recorded at my station around 20:00UTC on 8 December at a frequency around 6860kHz. This radar sometimes appears inside the 40m Amateur band as well.

Above this post you can see a waterfall plot of the radar signal. It’s the wide red signal. It is 15kHz wide and pretty strong, but severely affected by frequency-selective fading. Looking at the IQ recording in Audacity, it is clear that the radar uses pulses with a 50Hz repetition rate. This explains the characteristic sound of this radar when received with a conventional SSB radio. It sounds similar to AC hum (here in Europe, of course).

Continue reading on Daniel’s blog…

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