New season of The Divided Dial dives into the world of shortwave radio

NINA MOINI: We've been talking a lot by Public Radio today, obviously, during our Spring Member Drive. But for this next segment, we're going to tune in to a completely different kind of transmission. Shortwave radio. It can travel much, much farther than FM and AM radio, as in across continents, rather than say, across the state. And the ability has made it a powerful tool for governments, extremists, or really anyone trying to get their ideas to a faraway audience.

Minneapolis based journalist Katie Thornton tells the story of shortwave radio in the second season of The Divided Dial. It's an award-winning series on WNYC. Their program, which is called On the Media, a wonderful program.

Katie joins me now on the line. Thanks so much for your time this afternoon, Katie.

KATIE THORNTON: So nice to be here with you, Nina. Thank you.

NINA MOINI: I listened to this episode. It's out now, the first episode here of the season.

Fascinating. I learned a lot. Tell our audience again, just, what really is shortwave radio, and why can it travel so far?

KATIE THORNTON: Yeah. Great question, and thanks for tuning in.

As you mentioned, this is a different type of radio than we're used to. Different from the AM and FM that we can pick up in our car, on our home radio set.

You need a different receiver to pick it up, but they're accessible. They're really cheap.

And basically, shortwave radio, it's very low fidelity. Like, it doesn't sound great. But thanks to the weird quirk of science, it can reach thousands and thousands of miles without the internet, without a data plan, without satellites.

And the way it does this is it uses a separate set of frequencies, higher frequencies. So if you picture your AM dial, and imagine it just keeps going off and off to the right and to higher and higher frequencies, that's where the shortwaves are.

And they work differently because with a normal, say, AM transmission, most of the time, what you're hearing is a transmission that's coming to you, basically, line of sight. From the top of a radio tower into your receiver, maybe 50, maybe up to 100 miles away.

But with shortwave, on these higher frequencies, shortwave broadcasters will actually shoot a radio transmission up into the sky-- It's called a sky wave-- and it bounces off this upper layer of the atmosphere-- it bounces off of the ionosphere, and it comes back down to Earth hundreds, even thousands, of miles away.

NINA MOINI: It's so fascinating. And in the podcast, I liked this, that you described, the early days of shortwave were like internet before the internet, and people were hopeful about the connection. What were those early days like?

KATIE THORNTON: Yeah. In the past, especially by the late 1930s, shortwave radio was ubiquitous. Most of your home radio-- most of your home radio sets had AM as well as shortwave on the dial.

And like you said, the early days were really, really optimistic. Broadcasting, radio broadcasting, as in from one to many, that really started in the early 1920s. Before that, radio was all one-to-one transmission. It was sort of long distance walkie talkies. So this is messages between ship captains, between the military.

And another group that was on the radio waves in those early days were amateur radio operators. People who were just sort of tinkering with the new technology and looking to reach as far as they could.

And during World War I, when all radio was still this one-to-one transmission, the federal government ended up sort of getting a little bit nervous about interference. Like, we don't want these amateurs, who are just sort of having fun, we don't want them interfering with our military transmissions, things like this.

And so the federal government ended up sort of setting aside a set of frequencies specifically for the amateurs. And they said, you can have these shortwave frequencies. At the time, people thought they were pretty much useless.

But in the late teens and early 20s, these amateur radio operators were experimenting on the shortwaves, and they realized that they could get really, really far, thousands and thousands of miles. And so a lot of the early AM stations operating out of the US in the 1920s and the 1930s were really excited about that potential.

And so American stations-- AM stations started sort of rebroadcasting their signal on shortwave, reaching as far as South Africa. Other stations sprung up in other parts of the world, and there was really this global community that was building. It was the first time that people could be heard instantaneously across vast, vast distances, without having to pay for a phone call across a scratchy copper wire. It really blew people's minds, and there was a lot of hope about it.

NINA MOINI: Yeah. And a lot of hope. Governments, though, did start to use shortwave, correct? And it can get kind of hairy when governments begin to do that.

KATIE THORNTON: Well, certainly. You know, there-- Pretty early on, a lot of governments recognized the power of this ability to communicate globally, instantaneously globally, for the first time. And there was this optimism, especially in the wake of World War I.

But during World War II and during the Cold War, the medium really became a platform for information warfare, for propaganda. This really started with World War II The German state broadcaster had been developing an audience around the world for years prior to the war, with things like orchestral music. But in the early days of the war, they started pushing out Nazi propaganda with, you know, bespoke messages tailored at different countries that they were beaming their signal to, in language. They're beaming this propaganda into the US in English.

And so, it's really during World War II that shortwave becomes a tool for governments and for warfare. This is the time when, what would come to be known as, the BBC World Service gets its start. And this is also the time when the Voice of America got our start broadcasting out of the US.

NINA MOINI: Say more about that because that's relevant to this series, too.

KATIE THORNTON: It certainly is, and it's relevant to the present, as well. And we can talk more about that.

But during World War II and during the Cold War, especially, a lot of government services, they were really a sort of fierce battleground in wartime. Especially during the Cold War, you have the Voice of America, you have the BBC World Service, and you have them competing with large entities like Radio Moscow and Radio Havana, which are of offering competing and complementary perspectives during the Cold War.

The Voice of America, the idea from the very beginning, this hasn't always been perfectly executed, but the idea from the beginning was that the free press is going to be the best advertisement that you can have for the US. And although it hasn't always been perfectly executed, it's been very valuable and effective tool over the decades at getting information and reportage out to parts of the world that aren't necessarily able to hear some of that information otherwise.

NINA MOINI: President Donald Trump's administration has announced some recent new plans for Voice of America, right?

KATIE THORNTON: Yes. That's right. I think the most important thing to note that is the rollback. The Voice of America has been operating since the 1940s. It did start as a shortwave program, but in the intervening decades, of course, they've expanded to different media. AM radio, television, the Internet.

But in March, the Voice of America was ordered to halt most of their operations and most of their broadcasts. And so, the VOA, until very recently, was on all sorts of these platforms, including shortwave radio. And a lot of the VOA's streams and shortwave broadcasts have been silent since March.

And just last week, Kari Lake, who is the person Trump picked to oversee the VOA, she said on X that she plans to send the feed of the ultra-politicized, pro-Trump, one America news over the Voice of America's existing platforms.

I do want to note, it is unlikely that she will be able to do that. She doesn't necessarily have the editorial power over site to do that. But I think that the threat alone is really notable, especially at a time when our public media domestically is under threat due to supposed bias.

NINA MOINI: And so a lot of what we're talking about was just the first episode. I don't know if you're going to talk about what's going on later in the series, current, present day. Where does the series go from here? And remind folks how they can listen?

KATIE THORNTON: Yeah. Thanks so much for asking.

It's a really far-reaching series. We tried to cover a century of history in just four episodes and also, look to the future.

NINA MOINI: Right.

KATIE THORNTON: So you're right. The first episode, we really covered the first sort of half century plus of the medium. Starting this next week, on episode two, we're going to look at how the medium of shortwave went from a propaganda tool for government to a propaganda tool for anti-government extremists, specifically within the US, and that was really in the '90s and into the 2000s, and really just how much this little known medium shaped a lot of the far-right movements that we're quite familiar with today within the US. And so that's kind of what we're looking at in episode two.

From there, we're taking a look at the strange trajectory that shortwave has taken in the internet era. And to do that, we're looking into one very particular station that I was able to go and visit last year. Quite an interesting story there.

And in the final episode, we are going to be talking about the present and the future, because even though a lot of people don't that shortwave radio is even a thing still today. There's a super fascinating battle taking place on the shortwave right now between radio fanatics and Wall Street, and it reveals a lot about how we regard our public airwaves that we all share.

NINA MOINI: Katie, thank you so much for stopping by. I learned so much.

KATIE THORNTON: Thank you so much for having me and for listening to the series through on the media.

NINA MOINI: Thank you, Katie Thornton is an award-winning print and audio journalist based in Minneapolis. You can hear The Divided Dial season two on FM radio by tuning in to WNYC. Their show called On the Media, it airs at 2:00 PM on Sundays, right here on MPR News, or you can find it in the podcast form. The first episode, again, is out now.