Category Archives: AM

Radio Waves: Broadcast v Ham Radio, Marjorie Stetson’s Secret Wartime Work, Czech Republic MW Switch-Off, and PV RFI

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

Alike, but Not Alike: Broadcast vs. Ham Radio (Radio World)

Experience in amateur radio can be a boon to the radio engineer

Starting in the 1920s and through the ’60s, almost every broadcast engineer was a licensed amateur radio operator. That has changed a bit, but the importance of being a ham has not.

Both environments involve getting an RF signal from Point A to Point B. But it is interesting to note that radio broadcast and amateur radio are similar and yet so different.

For those who don’t know much about ham radio, I’ll tell you that communicating locally or internationally, via licensed amateur radio, can be a fascinating and challenging hobby. There are about 700,000 hams in the U.S. and an equal number worldwide.

Physics

Broadcast and amateur radio operate under the same laws of science. Transmitters, transmission lines, antennas and receivers make up an RF path to convey a message.

Broadcast engineers know that signal propagation on AM and FM bands is dramatically different. It is because our FM band is roughly 100 times the frequency and 1/100th the RF wavelength of that on the AM band. Engineers also know that 950 MHz STL signals are line-of-sight and roughly a 10-times jump in frequency from FM broadcast frequencies. Each band has its own challenges in getting a useable signal through. [Continue reading…]

A Canadian opens up about her secret wartime work — eavesdropping on Japan (CBC)

Retired sergeant remembers what it was like on the ‘front line of the radio war’

At age 97, Marjorie Stetson has never told anyone her secret code number — until now.

That’s the identity code — 225 — that she typed on every page of her highly classified work for the Canadian Armed Forces during the Second World War.

The retired sergeant’s wartime work was so covert, she said, she had to sign 15 separate copies of Canada’s Official Secrets Act.

“Nobody knew where I worked,” Stetson told CBC News from her home in Massachusetts ahead of Remembrance Day. “Nobody knew what we did. Even my parents never knew what I did in the service.”

Her husband, an American sailor she met at a celebration marking the end of the war, passed away a decade ago. She never told him what she really did during the war.

Today, Stetson herself is only now learning about the true scope of her role and the significance of all those sheets of white paper she filled with encrypted messages from Japan. [Continue reading…]

Czech Republic: MW Switch-Off by 2021 (Radio Reporter)

Czech public radio ‘?eský Rozhlas‘ is stepping up its information campaign for listeners receiving mediumwave programmes, ahead of the planned switch-off of transmitters by the end of 2021. Since 1 November, more announcements have been broadcast to warn users and a call centre has been set up to explain the possible listening alternatives (from FM to DAB). In the run-up to Christmas, public radio will launch an intensive advertising campaign in the print media and online magazines on 22 November to promote the purchase of digital DAB receivers to replace analogue radio. [Continue reading…]

The impact of photovoltaics (Southgate ARC)

Seamus Ei8EP reports on the IARU Region 1 website that the 358 page Final Report on the Study on the evaluation of the Electromagnetic Compatibility Directive has now been published.

It is publicly available, free of charge, from the Publications Office of the European Union. The Political Relations Committee of the IARU Region 1 responded recently to a European Commission Roadmap on the environmental impact of photovoltaics.

The radio spectrum is an important finite natural resource which must be protected. While PV technology of itself is to be welcomed, the IARU submission pointed out the inherent problems of non-compliant installations, particularly the installation or retro-fitting of optimisers which can produce significant spectrum pollution for very limited efficiency increase.

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Radio Waves: Radio and Education, Border Blasters, FM Switch Delayed per DCMS, and A Quick Temporary AM Antenna

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Radio Waves: Stories Making Waves in the World of Radio

Can Radio Really Educate? (JSTOR Daily)

In the 1920s, radio was an exciting new mass medium. It was known for providing entertainment, but educators wondered if it could also be used for education.

It was mid-1922 and America was in the midst of the radio craze. Commercial broadcasting had emerged in a handful of cities in 1920, but at that time, few people had a receiving set—except for amateur radio operators, who knew how to build one. It wasn’t even called “radio” back then—newspapers referred to it as “radiophone” or “wireless telephone.” But only two years later, there were several hundred radio stations on the air, and you could purchase a radio in a store—although hobbyists still had fun trying to build their own, with varying degrees of success. Meanwhile, the word “radio” had become the common term for that wonderful new invention that everyone wanted in their home.

Today, we tend to take radio for granted; it is one of many ways to hear music or news or sports. But in 1922, radio was unique: it was the first mass medium to take people to an event in real time, and listeners were amazed by it. Suddenly, they could hear a popular orchestra coming through the radio set. Without leaving their home, they could listen to a baseball game, or an inspirational talk from a preacher; some stations even had the latest news headlines. In an era when traveling from one city to another could take hours (the popular Model T Ford had a top speed of 40-45 mph, and superhighways had not yet come along), listeners could travel by radio, hearing stations from distant cities. Before radio, only the wealthy could attend a concert featuring a famous vocalist, but now, anyone who had a receiving set could hear that singer’s music. And in an America that was still racially segregated, radio gave some musicians of color the opportunity to be heard by thousands of listeners. In magazines and newspapers, radio inspired “utopian hopes and bold predictions.” Writers referred to it as a cure for loneliness—especially for people living in rural areas or on the farm. It was also praised for helping the blind gain greater access to the world around them. More than one writer claimed radio would bring world peace, since everyone would unite around their favorite programs. And of course, as a sign of American progress, it was something no home should be without, not even the White House: President Harding was an enthusiastic radio fan, and had a set installed near his desk, so he could listen whenever he wanted to. [Continue reading…]

Psychics once ruled the airwaves thanks to the Texas-Mexico border and the magic of radio (KUT)

A new book includes details of how powerful radio stations along the border helped former vaudeville actors reach larger audiences.

In the 1920s and ’30s, some of the most popular radio programs in the United States featured radio psychics. The most successful among them made hundreds of thousands of dollars reading the minds and predicting the futures of eager listeners. To do it, they took advantage of a new and mysterious medium: radio. Continue reading →

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Radio Waves: X-Class Flare & Halloween CME, Ham Callsign History, 2/3 UK Listeners Now Digital, AM/FM Until 2030, and Rampisham’s New Plan

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Radio Waves: Stories Making Waves in the World of Radio

Significant X-class solar flare (Southgate ARC)

There was a global eruption on the sun today. It started with a powerful X1-class solar flare from sunspot AR2887.

The blast created a massive tsunami of plasma in the sun’s atmosphere, which rippled across the entire solar disk. A CME is probably heading for Earth, raising the possibility of a geomagnetic storm on Halloween. More information and updates @ Spaceweather.com.

Solar Flare Alerts: Sign up for Space Weather Alerts and get instant text notifications when solar flares are underway.

History of the Ham Radio Callsign (Southgate ARC)

In this video Mike Ritz W7VO looks at the history of amateur radio call signs in the United States

Every legal amateur radio operator in the world has a unique callsign assigned to them by their government, and many of us are better known by our callsign than our given name. But what world event was it that caused these monikers to be? Why are they constructed the way they are? Continue reading →

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Gary DeBock’s XHDATA D-808 loopstick model

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Many thanks to SWLing Post contributor, Gary DeBock, who shares the following:

The 7.5 inch (19cm) loopstick XHDATA D-808 model was designed to be the ultimate AM-DXing (or Longwave DXing) travel portable, and can be built for a construction cost of around $30 US. It has already been used by numerous DXers to track down transcontinental and transoceanic AM-DX during overseas travel, and the orange plastic loopstick frame allows full operation of the whip antenna for FM and Shortwave reception.

The modification procedure isn’t difficult, and the full construction article is posted at

https://dreamcrafts.app.box.com/s/5d0pi85jfptgmrj4pd0jsmaybgb6gteh

A video demonstration of its daytime DX performance (compared to the stock model) has been posted on YouTube:

Build one, and join the fun! 🙂

Many thanks for sharing this, Gary! Your ultralight DXing creations are simply amazing!

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Radio Waves: FM CB, Radio Listeners in Zimbabwe, Tom Clark SK, and SAQ Grimeton UN-Day Transmission

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Radio Waves: Stories Making Waves in the World of Radio

Biggest change for CBs in four decades as FM mode gets approved by FCC (CCJ Digital)

The biggest change for CB radios in the U.S. since the late 1970s is coming and it looks to be a good thing for improved voice quality and cutting through frustrating background noise common at the peak of day.

The Federal Communications Commission (FCC) recently approved FM to join alongside AM and single-sideband (SSB) modes on CBs. It’s a big change to old technology that offers some clear advantages.

On the plus side, FM will provide users with improved audio quality and greater ability to circumvent background signal noise typical on CB’s long-standing AM side. The Department of Electrical Engineering and Computer Sciences at U.C. Berkeley reports that FM will provide an “improved signal to noise ratio (about 25dB) with regards to man-made interference” over AM. That kind of reduction in background noise could prove popular with truckers who remain among the top users of CBs in the U.S.

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Guest Post: A synchronous detector crash course!

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Many thanks to SWLing Post contributor, 13dka, who shares the following guest post:

Revisiting the Belka’s “pseudo-sync detector”: A sync detector crash course!

by 13dka

“It’s usually hard to assess whether or not a sync detector helped with a particular dip in the signal or not, unless you have 2 samples of the same radio to record their output simultaneously and compare.”*

That’s what I wrote about the “pseudo sync detector” in my review of the Belka DSP last year.

Since I was recently upgrading to the Belka DX in order to pass on the Belka DSP to a friend, I had briefly two examples of almost the same radio on the table at the dike. I tuned them to the same stations and recorded some audio clips with one radio on sync detector, the other in regular AM mode, to answer the question whether or not sync has “helped with a particular dip in the signal”. Then I thought that demonstration would be an opportunity to try an explanation on what exactly (I think) sync detectors are all about anyway, hoping to find a middle ground between “technical” and “dumbed down beyond recognition”.

The trouble with sync detectors

Perhaps no component of a shortwave receiver is surrounded by so much misconception and confusion as sync detectors. Full disclosure: Until quite recently, I had an, at best, vague concept on what they do myself. It seems it’s not so much that people don’t know how they work, what they actually do when they work is where the ideas often diverge. Continue reading →

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Radio Waves: “Shady” 5G, Chip Shortage Affects Radio Tech, CW Contesting’s “Secret Storm,” ARRL to Cover Youth FCC App Fees, and ARRL Response to Insulin Pump Story

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Radio Waves: Stories Making Waves in the World of Radio

Many thanks to SWLing Post contributors Wilbur Forcier, Dan Van Hoy, and the Southgate ARC for the following tips:

Special operators are already dealing with a shady piece of Chinese technology the US has been warning about. (Business Insider via MSN)

The spread of 5G mobile communications technology is creating new problems for the US military.
Compromised networks could give adversaries an opportunity to monitor and attack US personnel.
See more stories on Insider’s business page.

In an increasingly interconnected world, the US military is facing new challenges in old stomping grounds.

Even though the US isn’t at war with China, competition with Beijing is already raging, and conventional and special-operations troops deployed around the world are exposed, either directly or through proxies, to Chinese technology that could hinder them in a conflict.

The worst offender is 5G, the same mobile communications technology ordinary people use or will be using in the future.

[…]However, Chinese firm Huawei – which is suspected of stealing its 5G technology from a Canadian firm through cyberattacks – has been deploying its 5G technology worldwide.

Given China’s peculiar national security laws, which require individuals and companies to cooperate with the Chinese security services, any Huawei technology around the world is a potential threat to privacy and national security. Through Huawei, Beijing could spy on or disrupt infrastructure and operations during peace or war.

Governments have realized the danger and have been banning Huawei from their networks. The British government did so in 2020, and the US Federal Communications Commission designated Huawei a national security threat in 2021, following several Chinese cyberattacks.[…]

Chip Shortage Hits Radio Technology Marketplace (Radio World)

The severity of the global computer chip shortage has broadcast equipment manufacturers finding creative ways to manage supply channels while trying to meet product demand.

Despite the semiconductor shortages, people in the radio technology marketplace who spoke with Radio World say products are still being shipped, with mostly minor delays, thanks to prior planning. Equipment suppliers said they hope the semiconductor shortage will ease soon, perhaps by early 2022.

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