Category Archives: Mediumwave

Don Moore’s Photo Album: Loja, Ecuador

Iglesia San Francisco, Loja

Many thanks to SWLing Post contributor, Don Moore–noted author, traveler, and DXer–for the latest installment of his Photo Album guest post series:


Don Moore’s Photo Album: Loja, Ecuador

by Don Moore

A few months ago I did a two-part feature on my favorite small Latin American city, Cuenca, Ecuador.  This time let’s journey to a nearby smaller city that I don’t know very well but want to spend more time in.

Loja is about two hundred kilometers south of Cuenca on a paved highway that runs through a long valley before climbing into the mountains to twist and turn the rest of the way. Look at the route on Google Maps and you’ll see what I mean. Today it’s a picturesque four-hour bus ride but when I made the trip the first time in 1985 it was a tortuous twelve-hour journey on rough dirt roads.

The roads today may be smooth and paved but Loja is still the most isolated major town in Ecuador. The city is so far south that it is closer to the Peruvian border than it is to any other town of size in Ecuador. This isolation has both forced the region to be self-reliant and cushioned it from problems in the rest of the country. For three years in the mid-1800s the province of Loja even governed itself as a peaceful independent country while the rest of Ecuador was mired in a bloody civil war.

One of Loja’s many picturesque streets.

Loja’s population of around 200,000 (a third the size of Cuenca) makes it the twelfth largest city in Ecuador. But Loja is one of those places that has always punched above its weight. The economy is strong as it’s the center of one of the best coffee growing areas in South America and the city is the main transit point for the gold fields to the east in the Ecuadorian Amazon. Loja is widely thought of as the most cultured and educated city in the country. Two of its universities rank in the country’s top ten. And everyone agrees that Loja is the center of Ecuadorian music. One of the city’s several museums has room after room filled with displays about the many famous musicians that have come from (and continue to come from) Loja. Free concerts are held in the city’s plazas at least once a week.

Loja has always been forward-looking. In 1890 the city installed one of the first hydroelectric generators in all of South America. That was just eight years after the first plant was installed in the United States. A little over a century later, in 2013, the first windfarm in continental Ecuador was constructed on a ridge above the city. The eleven windmills produce sixteen megawatts and phase two of the project, which is now under construction, will add another forty-six megawatts. A recently approved third phase will add another 110 megawatts.

Windmills overlooking Loja

The First Visit

My first visit to Loja was in March 1985 after that long twelve-hour bus ride from Cuenca. I remember Loja as being a pretty but sleepy small city. We only stayed two nights and one day. My primary goal was to visit Radio Centinela del Sur and get a QSL for myself and several friends. I don’t recall anything from that long ago visit but I did get the QSLs. Radio Centinela was founded in 1956 so it wasn’t the first radio station in Loja. But it was the first one to last for more than a few years. On shortwave Radio Centinela del Sur was a station that changed frequency a lot. I first heard it in 1974 on 5020 kHz but most of my logs were made in the early and mid-1980s when 4890 kHz was in use. In the 1990s Radio Centinela del Sur used 4771 and 4899 kHz at various times. The station left shortwave for good by the late 1990s.

Radio Centinela de Sur in 1985

Business card from 1985

The second oldest station in Loja was Radio Nacional Progreso, founded in 1958. I have many logs of the station on its 5060 kHz (variable) frequency from the 1970s through the 1990s. I don’t remember why I didn’t visit them in 1985. Maybe the office was outside of town and difficult to get to. Loja’s other shortwave station was the Catholic broadcaster Radio Luz y Vida, founded in 1967. In the early 1970s the station used 4825 kHz on shortwave but around 1978 they switched to 4850 kHz. I last logged them there in 1997. Radio Luz y Vida was only a few blocks from our hotel and I stopped by several times but the inner door was always locked and I never got to see more than the entrance way. Continue reading

Radio Waves: The Discovery Dish Pre-Launch, China Radio International, Hackaday Prize, and Baseball 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 Dennis Dura and Ulis (K3LU) for the following tips:


Discovery Dish Pre-launch: A Lightweight Dish And Feed For L-band Weather Satellites And Hydrogen Line Reception (RTL-SDR Blog)

For the past few years we have been working on finding the best way to help beginners get started with L-band weather satellite reception and basic radio astronomy. We have now come up with a solution that we’re calling the ‘Discovery Dish’ – a lightweight 65 cm diameter dish and active filtered feed set.

The Discovery Dish will be crowd funded, and we currently have a pre-launch page set up on Crowd Supply. So if you are interested, please visit the pre-launch page and click on the Subscribe button for updates.

Discovery Dish is a 65-cm diameter aluminum satellite dish and active filtered feed designed for receiving GOES HRIT, GK-2A LRIT, FengYun LRIT, NOAA HRPT, Metop HRPT, Meteor M2 HRPT and other weather satellites that operate around 1.69 GHz. The dish is designed to weigh under one kilogram, and it splits into three petals, making it easier to ship worldwide. The 1.69 GHz feed contains a built-in LNA right at the feed point, as well as filtering, which means that there is almost no noise figure loss from cables or connectors.

Note that the prototype images show an early non-petalized prototype with rough laser cut wind holes. The production version will obviously be a lot neater looking! […]

Click here for more details about the Discovery Dish campaign.

How China’s Propaganda Infiltrated Radio Stations in Europe (The Diplomat)

State-owned China Radio International is airing its content without attribution on commercial radio stations in Europe.

China has consistently and systematically pursued the dissemination of its narratives on the global stage, with the primary aim of shaping the international landscape to align with its strategic interests and ideological perspectives. These endeavors encompass a diverse array of tactics, including the acquisition of media enterprises, active engagement by Chinese ambassadors in both mainstream and fringe media outlets, the utilization of paid supplements, collaboration with pro-Kremlin media, and the steadily expanding presence of China across various social media platforms.

Recently, China Radio International (CRI), an official Chinese state media outlet broadcasting in multiple languages, has garnered attention for its establishment of partnerships with and provision of content to radio stations worldwide. Remarkably, CRI has effectively outsourced the production of China-related programming to local partners, often without transparently disclosing the sponsorship of content creation to the listeners. This strategy, known in Chinese as “borrowing a boat to go out on the ocean,” plays a pivotal role in laundering Beijing’s propaganda and fostering the acceptance of its messaging among local audiences.

One illustrative case of this approach within Europe involves two Czech radio stations, namely Radio HEY, a nationwide commercial radio station airing rock music, and Radio Color, which positions itself as “one of the last independent radios.” From 2019 to May 2023, these radio stations broadcasted a program titled “Barevný sv?t” (Colorful World), a nearly 30-minute segment aired six times a week, with the objective of acquainting Czech listeners with Chinese culture, language, and history. [Continue reading…]

Hackaday Prize 2023: A Software-Defined Radio With Real Knobs And Switches (Hackaday)

When cheap digital TV dongles enabled radio enthusiasts to set up software defined radio (SDR) systems at almost zero cost, it caused a revolution in the amateur radio world: now anyone could tune in to any frequency, with any modulation type, by just pointing and clicking in a computer program. While this undoubtably made exploring the radio waves much more accessible, we can imagine that some people miss the feeling of manipulating physical buttons on a radio while hunting for that one faint signal in a sea of noise. If you’re one of those people, you’re in luck: [Kaushlesh C.] has built a portable, self-contained SDR system with real knobs and switches, called SDR Dock 1.0.

The heart of the system is a Raspberry Pi running GQRX, an open-source SDR program that supports many different RF modules. [Kaushlesh] used an Airspy HF+ Discovery, a compact receiver that can work the HF and VHF bands, but it’s easy to modify the SDR Dock to accept other types like those ubiquitous RTL dongles. A seven-inch LCD screen with integrated speakers forms the main output device, with everything powered by a 10,000 mAh lithium-polymer battery. [Continue reading…]

With the future of AM unclear, a look back at the powerful role radio plays in baseball history (Citizen Tribune)

Many baseball fans, especially older ones, originally fell in love with America’s pastime by listening to ballgames on AM radio

Click here to browse this gallery.


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The Great Medium Wave Grey Line Challenge

By Jock Elliott, KB2GOM

According to https://dx.qsl.net/propagation/greyline.html: (the image above comes from them)

The “grey line” is a band around the Earth that separates daylight from darkness.  Propagation along the grey line is very efficient.  One major reason for this is that the D layer, The “grey line” is a band around the Earth that separates daylight from darkness.  Propagation along the grey line is very efficient.  One major reason for this is that the D layer, which absorbs HF signals, disappears rapidly on the sunset side of the grey line, and it has not yet built upon the sunrise side. Ham radio operators and shortwave listeners can optimize long distance communications to various areas of the world by monitoring this band as it moves around the globe. which absorbs HF signals, disappears rapidly on the sunset side of the grey line, and it has not yet built upon the sunrise side. Ham radio operators and shortwave listeners can optimize long distance communications to various areas of the world by monitoring this band as it moves around the globe.

Elliott’s short version: Some funky stuff can happen with propagation when the grey line is passing through your location.

So let’s have some fun for a couple of hours chasing MW DX along the grey line.

Here are the rules:

  1. Frequency range is the medium wave band: 520-1710 kHz
  2. From one hour before Civil Twilight your local time on Saturday, October 14, to one hour after Civil Twilight at your location.
  3. Any radio with any antenna, but must be the radio at your location (no using remote internet radios)
  4. The listener must hear the signal in real time
  5. The stations must be ID’ed by listening to the signal.
  6. Your report should include:
    • Your name (or Internet handle)
    • Your receiver and antenna (stay with the same setup from beginning to end; if you use multiple setups, provide a separate report for each).
    • Your location
    • The time, the frequency, and the ID of each station heard
    • The total mileage of your top five most distant stations.

A final point: this is not a contest; it is a challenge. The reward for every participant will be fun and fellowship.

You can find when Civil Twilight begins at your location by visiting www.wunderground.com  . Enter your location, click on “Full Forecast” then scroll down to the “Astronomy” section.

Please Share: Introducing the “I listen” project

By Jock Elliott, KB2GOM

To paraphrase a line from John Fitzgerald Kennedy: “Ask not what your station can do for you, ask what you can do for your station.”

Think of this as a reverse QSL program . . . but I get ahead of myself.

I was perusing the news a while back, reading about the closure of radio stations in the U.S. and how e-vehicle manufacturers did not want to include AM (MW) radios in their vehicles . . . and . . . I snapped.

“The reason they are closing,” I snarled, “is that they think no one is listening . . . but WE listen!”

So I offer, for your consideration, a modest proposal . . . the “I listen” project.

Let’s do this!

All I ask is that each and every one of you who reads this is that you send a postcard or a letter to your favorite station – AM, FM, or shortwave – that says in BOLD letters at the top I LISTEN! Further down on the postcard or letter, you should explain what you listen to, and what you enjoy.

So here would be a sample from me:

From: Jock Elliott, Upstate New York

To:       Talk 1300 AM & 98.7 FM WGD, 11 Dennis Terrace
Schenectady, New York 12303

I listen!

To Talk 1300

To the Jack Catham show because I really like the calm way he presents the issues and interacts with callers.

That’s it. Of course, if you want to send more than one postcard or letter, great!

The point is to let the station know without a doubt that you listen. Why a postcard or letter? Because it is a physical piece of mail that is hard to ignore. By contrast, an email or a text is much easier bypass or ignore.

So make sure that your favorite station or two knows that you listen, and let me know here.

I’ll end by paraphrasing Arlo Guthrie: “Can you imagine fifty people a day, I said fifty people a day, sending “I listen” postcards to their favorite stations? And friends, they may think it’s a movement!”

And bear in mind, this is not the time to be asking for goodies in return.

How DXers can contribute to ionospheric research during the October 14, 2023 solar eclipse!

Many thanks to SWling Post contributor, Nick Hall-Patch, who shares the following announcement:


How DXers can contribute to ionospheric research during the 14 October 2023 solar eclipse

There will be an annular solar eclipse on 14 October, 2023 when, at totality, the size of the Moon’s disk will appear slightly smaller than the size of the Sun’s disk.  This eclipse will affect all of North America, as well as Central and part of South America, as seen in the map below.

AM Broadcast Band DXers know that the blocking out of radiation from the sun during a total solar eclipse can introduce temporary night time listening conditions over an area far beyond the path of totality.

The upcoming annular eclipse is expected to have a similar effect on daytime medium wave listening conditions as would a total solar eclipse, and should not be missed by DXers.  Live listening can be done during the eclipse, as well as recording the entire medium wave band, using SDRs (software defined radios).

There might be more to our DXing results than new and unexpected receptions of distant radio stations, however.  The rapidly changing listening conditions will be indicating a similarly turbulent ionosphere, and DXers’ documenting those listening conditions through SDR recordings could provide information that will be useful to scientists who want to gain a better understanding of the Earth’s ionospheric dynamics.

How can DXers contribute to ionospheric research?

HamSCI is an organization of volunteer citizen-scientists and professional researchers who study upper atmospheric and space physics, and will be interested in examining MW DXers’ wideband SDR recordings made during both eclipses, and indeed, in having DXers assist with HamSCI’s research.

It will be important to have many participants in this project.  To sign up, please go to https://hamsci.org/mw-recordings/ and discover how to make sure that those DX files will also qualify as scientific data that can become part of the public record.

Those interested in finding out about all the research that HamSCI will be doing during the upcoming eclipses, check out https://hamsci.org/eclipse .  Especially if you are also an amateur radio operator, there are several other ways that you might contribute to the project.

Don Moore’s Photo Album: Costa Rica (Part One) 

Radio Reloj, Costa Rica (1990)

Many thanks to SWLing Post contributor, Don Moore–noted author, traveler, and DXer–for the latest installment of his Photo Album guest post series:


Don Moore’s Photo Album: Costa Rica (part one) 

by Don Moore

Costa Rica is one of the most visited countries in Latin America. I only visited there once, for three weeks in May-June 1990 when the country was just beginning to become a major international eco-tourism destination. Visitors were few and prices very affordable. Except for a short trip to the Monteverde cloud forest, we spent all our time in the central valley, staying in San José and nearby Heredia. Rather than nature, our visit focused on cultural and historical sites … and a lot of radio stations.

Since the 19th century, Costa Rica has been one of the most literate and educated countries in Latin America. That quality is reflected in its radio broadcasting industry, which has always been very professional. Curiously that’s even reflected in station verifications. Almost every Costa Rican shortwave station that I’ve verified had a professionally printed QSL card.

Despite being one of the smallest countries in Latin America, Costa Rica had a lot of shortwave radio stations. I have fifteen in my logbooks and some of the most famous ones were already off the air when I started DXing. Unfortunately, shortwave broadcasting from Costa Rica ended almost twenty years ago so there’s no more to be had. It is still possible to log Costa Rica on medium wave but it’s not as easy as it once was. When I started DXing in the early 1970s, stations in the San José were spaced twenty-five kilohertz apart. That meant that every other station, such as Radio Sonora on 675 kHz and Radio Columbia on 725 kHz, was on a split frequency that fell between the normally assigned 10 kHz channels. I logged nine Tico stations on medium wave while DXing from Pennsylvania in 1972-1981 and only one of those, Radio Reloj on 700 kHz, was on an even channel.  Those split channels were eliminated in the 1980s so logging Costa Rica on medium wave is no longer a slam-dunk.

I visited a lot of radio stations and took a lot of photos on my one long-ago trip to Costa Rica. I’m going to focus on just five shortwave broadcasters in this first look at Costa Rica. The others will be featured in two or three future columns.

In the 1970s the first Costa Rican station most shortwave DXers heard was Faro del Caribe, or Lighthouse of the Caribbean. This religious station used two kilowatts on 9645 and 6175 kHz and got out surprisingly well as long as there wasn’t a more powerful international broadcaster also using the same frequency. In the late 1970s they added 5055 kHz in the sixty-meter band.

When I visited in 1990 the antennas were located right next to the studio building. The site was outside the city of San José when the station was founded but gradually a residential area built up around it.

Engineer checking one of Faro Del Caribe’s shortwave transmitters.

Fortieth Anniversary pennant from 1988. When Faro del Caribe began broadcasting on February 23, 1948, it was the first Evangelical Protestant radio station in Central America.

For DXers, Radio Reloj was one of Costa Rica’s best known radio voices for several decades. The station was founded as Radio Cristal by Roger Barahona in 1945. The shortwave frequency of 6006 kHz was added in the early 1950s. In 1958 the station was renamed to Radio Reloj when the format changed to focus on news and community announcements with very frequent time checks. (Radio Reloj means Radio Clock.) Roger’s brothers Isaac and Francisco had joined the broadcasting company and Radio Reloj was assigned the callsign TIHB for Hermanos Barahona (Barahona Brothers). Continue reading

Guest Post: A review of the Chaoyuan LC90 Hybrid Shortwave/4G/Internet Radio

Many thanks to SWLing Post contributor, Michael Ye (BD4AAQ), for the following guest post:


The LC90, a Great Radio Spanning Two Worlds

by Michael Ye (BD4AAQ)

It is an awkward era for radio receivers. Although technology becomes more and more advanced and increasingly sophisticated radios are made, there are fewer and fewer stations to listen to. But hardcore radio hobbyists, mostly hams and shortwave listeners, would not give up the hobby. They continue to look for and enjoy stations among noises in the airwaves. Although Internet radios have been around for a long time, I never thought seriously about them. Perhaps I was stubborn, but in my mind, radios were noises and noises were radios and it’s the stations among the noises that I enjoyed. Receivers without noises were hardly real radios.

Until I got my first full band radio with Internet features. The LC90 was a pleasant surprise, completely changing the way I look at radio receivers. The LC90, or “full band smart Internet radio”, is my first shortwave radio AND Internet radio in one. There may be other radios with Internet features, but I have heard of few receivers that integrate the traditional radio (shortwave in particular) and the Internet. The LC90 was launched in China in early 2023, and quickly became popular among hobbyists thanks to the unique combination. News has been confirmed that the overseas version of the LC90 will be launched later this year. It provides more options for users at a time when shortwave broadcasters continue to shut down transmitters and bid final farewell.

Chaoyuan Company

The manufacturer of the LC90 is Chaoyuan, an electronics company based in Shenzhen, China, known for mobile phone design and Hi-Fi equipment. In recent years they started to design and make radios. And they are serious about the business, too.

The LC90 full band smart Internet radio

The Radio at a Glance

The radio is of regular size. A computer mouse is placed in the picture above, so you have an idea of not only the radio’s looks but also its size. The exact dimensions are 200x122x40mm. Its weight is 640 grams. The radio has a built in 4G SIM card, with 3G prepaid data. You have to add credit to the card in time by scanning a QR code on the screen before the built-in SIM card expires. You can also use your own SIM card by inserting it to a slot at the bottom of the radio. And of course, you could use Wi-Fi at home.

Although the radio is a combination of the traditional radio and the Internet, it is very ingeniously designed and does not put off the user with too many bells and whistles – you could press the tuning button to change the shortwave band and the fine tuning button to change the band width. The tuning button also serves as an “enter” key. These are clever designs that effectively save extra buttons. I have not seen a similar design in other radios.

For those who do not read Chinese, the upper five buttons are, roughly, “Configure”, “Timer”, “Setup”, “History” and “Favorites”. The four buttons on the left: “Confirm”, “Stations”, “News” and “Menu”. The four buttons on the right: “Back”, “Sequence”, “Rewind” and “Fast Forward”. The button with a globe says “Internet”.

The radio has excellent audio quality, rich bass, with a well-balanced frequency response. It is powered by two 18650 rechargeable lithium batteries. The radio has no back stand.

Traditional Radio

All three modes (or bands) are available, FM, MW and SW, as shown in the three buttons on the upper right (to get LW just press MW again). The FM band covers 64-108MHz, which includes Japan’s FM band. During the FMDX season you could have stations from Japan and other countries to explore. The SW band covers 2300-26100KHz, continuous, almost the entire shortwave band, more than enough for broadcast listening. The antenna jack works for all three modes (or bands).

Excellent Shortwave Performance

As a shortwave listener of many years, I am most interested in the radio’s performance in shortwave reception. Well, it is indeed very good in terms of sensitivity, selectivity and audio quality, with no compromise although the radio has an Internet section which requires additional space and resources.

When you use the radio indoor, reception could be poor and you can insert an external antenna to the antenna jack. Unfortunately, I cannot connect my AOR LA400 loop antenna to it as the antenna jack is too close to the tuning knob and so there is not sufficient space for the plug (see picture). Generally, a 3.5mm plug with a wire should work well if you extend the wire outside.

The external antenna jack

If there is a disappointment, its shortwave reception does not decode SSB signals. If the user is not a ham radio hobbyist, SSB reception may not be really needed anyway and the buttons, circuits and space can be saved accordingly.

Fair FM Reception

FM reception is good, but there is no obvious improvement of reception when an external plug is inserted in the antenna jack.

Mediocre MW Work

Reception on the lower bands, e.g., the medium wave band, is always a challenge in cities. It is not surprising that medium wave performance of the LC90 is mediocre at best. I don’t do much MW DXing but nowadays for each MW frequency there is almost always an FM frequency. Let’s face it – we should perhaps forget about medium wave reception in cities where there is excessive low band EMI.

However, if you go outdoor with the radio, medium wave reception can still be a lot of fun. And, contrary to FM reception, an external antenna significantly improves its performance!

Internet Radio

Admit it or not, the best days of traditional radio are gone, and while we continue to have fun on the old time radio, we should not hesitate to embrace newer technologies such as the Internet. By launching the LC90 and combining the two, Chaoyuan has made a significant move.

The Internet radio is an integrator of many online stations on the Internet, and more. It is completely different from the traditional radio which receives radio signals transmitted on air. The Internet radio, which relies on the Internet, provides much better audio quality, no noise, customizable and replay-able.

If you want to kill time and look for signals from noises, turn to shortwave and enjoy DXing. If you feel like listening to solid content or enjoying noise-free music, the Internet radio is there for you. This Internet radio integrates major web stations in China and on that basis the user can further select and configure their own favorites. Among apps that are built-in is Ximalaya FM, the leading audio platform in China. Due to requirements of policies and regulations in China, the user does not have much discretion to include foreign stations in the radio. However, Chaoyuan has indicated that they are working in an effort to secure authorizations from Spotify, Alexa and Pandora which they hope could be incorporated in the overseas version of the LC90. The future overseas version is expected to give the user more discretion to include online stations of their own choice.

A closer look at the display of the Internet Radio

Two buttons, Ai1 and Ai2, are voice assistants. Activate and speak to them and the radio directly plays the content (Ai1) or displays their findings for you to choose from (Ai2).

Finally, this is a radio with the most accurate time. There is no need to set the time for it, as it is based on the Internet.