My Descent into the World’s Strangest Radio Mystery
Numbers stations have confounded radio enthusiasts for decades. Are the broadcasts gibberish, or something more?
The shortwave radio arrived in a small cardboard box on the steps leading to my apartment. I was expecting some hulking thing—a bulky, outdated apparatus. But I picked it up with surprising ease, and inside my room, I opened the package to find a grey contraption the size of a large matchbox. The Radiwow R-108 looked like a kid’s toy with tiny, numbered buttons, an internal speaker, and dials on the side for tuning. A telescopic antenna laid across the top, and an additional wired antenna sat coiled inside its packaging.
My mission: use my Radiwow to pick up the signals that exist between most AM and FM broadcasts—those of the lesser-known shortwave spectrum. I looked down at this plastic $50 pocket radio and found it unimpressive compared to the vast walls of blinking dials and radar screens that agents use in the movies to track down spies and crack codes. It would have to do.
Among the rogue pirate broadcasts, weather transmissions, and air traffic signals that fill the shortwave radio band, there are stations of unknown origin that have confounded amateur radio enthusiasts for decades. Known by those in the community as numbers stations, these broadcasts stick to a familiar pattern, beginning with an identifiable signature—a string of notes from a song, a repeated word or a set of numerals. That’s followed by eerie, computerized voices that read off nonsensical streams of numbers for several minutes before descending again into the static.
To an average listener, these broadcasts might sound like gibberish, but radio hobbyists believe they are codes intended for intelligence agents in the field. As far as experts can tell, the CIA, Russia’s Foreign Intelligence Service, Cuba’s Dirección de Inteligencia, and other agencies are among those responsible for the broadcasts, although they rarely admit their involvement. Anyone with a shortwave radio can hear a numbers station transmission by tuning to the frequency from which it broadcasts. But only a person with a special, single-use cipher can decode the numbers and read the message that’s been transmitted.
It’s easy to relegate numbers station theories to the realm of pseudo-scholarship. After all, ours is a time of cyberwarfare, fake news, and Russian bots, which have all been subjects of real and imagined conspiracies in recent years. One theory holds that new 5G networks are to blame for the rapid spread of the coronavirus. That suspicion became so pervasive that the World Health Organization included an entry on its website that clarified that “viruses cannot travel on radio waves/mobile networks,” and the U.S. Department of Homeland Security warned of possible attacks against telecommunication workers. During the month of April alone, around 50 radio towers across Europe were set ablaze by conspiracists.
When I began my research into numbers stations, I found it absurd that governments are sending out signals for spies to receive in the U.S. or Russia or China–just as unlikely as the paranoid ramblings of coronavirus conspiracists. I’d been fascinated by the mechanical and melodic tonal quality of numbers station recordings, but I had always observed them from a safe distance, through YouTube videos or online databases. The pandemic offered an opportunity to put my skepticism to the test. So, I obtained a shortwave radio and began scouring the airwaves. In order to prove that numbers stations were real, I’d have to locate one—and decode it.
My partner Ryan and I had relocated from New York, where we both were attending school, to his grandmother’s home on the North Carolina coast to isolate ourselves during the pandemic. (Ryan’s grandmother had temporarily moved in with his family.) In the confined interior of my Brooklyn apartment, where even a neighbor’s power adapter or Wi-Fi router could cause interference, I had battled a cacophony of buzzes and sheets of white noise. Amid all of the chaos, I felt bad for wondering if the open sea air might improve the range of my Radiwow.
I placed my radio equipment beside the kitchen table and declared it my new headquarters. After fashioning the wire antenna to the chandelier, I began fiddling with the knobs. In the days ahead, Ryan would occasionally glance up from his laptop or a book with the kind of look that suggested I was up to something illegal. “Can you be done now?” he asked one night. I told him I was working, but to him, whatever I was doing didn’t look much like work. “That thing scares me,” he once told me before heading to bed.
Between seas of static, I came across Christian fundamentalists telling conversion stories, strangers speaking in languages I couldn’t recognize, and morse code stations sending out endless beeps. I would sometimes become convinced that I heard voices in the distance, beyond the static, beaming in through miles and miles of atmosphere. I’d do anything to make the signal a little clearer—stand on my chair or pin the antenna to the ceiling. But whatever I heard was always just out of reach.
I was looking for one of the distinctive signatures that sets each numbers station apart—someone repeating three numbers over and over again to help the listener verify that she has located the correct station. Several hours passed, and I looked down at the notes I’d scrawled to track my progress—the hurried, manic pen marks: 7,030 KHz, morse code; 7,255 KHz, constant beeping; 7,570 KHz, very faint voices; 7,780 KHz, quiet music and talking. They didn’t mean anything, and they led nowhere. It was 2 a.m., and I sat surrounded by bundles of tangled wires in the pitch black. Ryan’s soft breathing filtered in over the static; he’d been asleep for hours in the next room. I adjusted my headphones, pushed my glasses up the bridge of my nose, squinted into the digital glow, and carefully throttled the dial.
The first time I heard a numbers station recording must have been while listening to a peculiar part of “Poor Places,” a song by the band Wilco. As the song ends, a woman’s warbly voice repeats the phrase “Yankee Hotel Foxtrot,” as if under a spell of madness, behind a wall of distortion and roaring guitar feedback. The album the song appears on, one of the most celebrated of the ‘00s, is named after those three words, taken from the phonetic military alphabet. Wilco, I later learned, had sampled the clip from the Conet Project, a set of CDs released in 1997 by a London-based radio enthusiast named Akin Fernandez. His project is made up entirely of numbers station recordings gathered from listeners around the globe.
Numbers stations have never gone mainstream. You won’t find news pundits debating their usefulness or ethical implications on CNN, nor will they come up in a President’s speech. But after the release of the Conet Project, a cult community of artists, filmmakers, and musicians began incorporating the unsettling transmissions into their work. Numbers stations appeared in the Tom Cruise psychological thriller Vanilla Sky, the blockbuster video game Call of Duty: Black Ops, and the hit TV series Lost and The Americans. The uncanny nature of numbers station recordings also made them a perfect fit for David Lynch’s surrealist magnum opus, Twin Peaks.
After years of close monitoring, shortwave enthusiasts have built an impressive log of evidence to support their beliefs on websites and blogs like numbersoddities.nl or signalshed.com. They know when each broadcast will take place, down to the minute, and some of them track how those broadcasts change over time, in the hope that one day they will have enough evidence to decode a message and share it with the world.
Although their origins are unclear, there are several elements of numbers station broadcasts that listeners are sure of. For one, the structure of a numbers station transmission—the signature callout, followed by groupings of numbers—suggests that whoever is sending the broadcast must be employing a cryptographic technique known as the one-time pad. For this communication to be successful, two parties need to possess an identical string of numbers, which are sometimes printed in tiny notebooks for easy concealment. The sender devises a message and translates it into a set of numbers—A is one, B is two, and so on. Next, the sender adds each number to the randomly generated numbers listed on the one-time pad. When the receiver listens to the resulting numbers via shortwave radio, she’ll know to subtract them from the one-time pad to end up with the original message again.
This system is completely impossible to crack because each outcome is equally likely as any other. But according to Jonathan Katz, a cryptography professor at George Mason University, the one-time pad encryption scheme is more trouble than it’s worth. It’s a Catch-22: In order for the system to work as intended, two parties need to meet up and exchange pads in-person, which defeats the entire purpose of communicating internationally through the radio waves. Sending the pad via an online messaging system wouldn’t make sense either. “If you have the ability to exchange something in a secret fashion, then you might as well just exchange the message,” Katz told me. Besides, if a listener missed even a single number in the chain, the entire pad would become useless. One-time encryption was influential in the 1950s, but today, with advanced AI and computing systems, there are much more efficient and secure ways of staying in touch, Katz said. He had no idea why intelligence agents would use such an outdated system to reach each other, and neither did I.
In all of my airwave browsing, I may have come across a numbers station broadcast, but I would never have known it. None of the broadcasts I heard made much sense, and there was no distinguishing between what was supposed to be there and what wasn’t. I needed help, but no one would talk. Avid listeners fear that they could be arrested for monitoring clandestine transmissions. In nations like the U.K., it’s illegal to listen in on broadcasts that aren’t intended for the general population, and because governments keep their shortwave radio activity under wraps, no one knows what might happen if an enthusiast is caught.
I reached out to an enthusiast who’d written countless articles covering the shortwave band. One brief post mentioned that he’d occasionally come across numbers stations in his explorations. Certainly, if he was willing to attach his name to a public post about clandestine broadcasts, he’d be inclined to help me find one. Then, I received a message in my inbox. “Not sure why you contacted me about numbers stations,” his email read. “I am no expert—in all my years in the radio hobby, I think I heard one or two numbers stations and that was way back in the 1960s.” Folks at the Amateur Radio Club at Columbia University referred me to someone who, when asked if he’d be interested in talking, sent this message, unprovoked: “No—I’m not a government person—just shy.” The most elaborate story of all came from an expert in the Netherlands who told me he had recently suffered from a traumatic brain injury, resulting in a complete loss of his memories—including the ones about numbers stations. I have no evidence to suggest that this story was inaccurate. But after a long string of dead-ends, I had my suspicions.
Then I found Lewis Bush. A photographer and academic from the U.K., he became fascinated by the “perverse and paradoxical mixture of visibility and invisibility” that numbers stations inhabit—the fact that anyone can find them, but no one can know what they mean. Even if it was impossible to decode the messages themselves, Bush thought, maybe someone could at least locate their transmission sites. He searched for numbers stations with the help of satellite imaging technology. He would find irregular blotches of grass or other visual anomalies that might clue him in to the whereabouts of a particular site, and with a patchwork of zoomed-in images, he’d create composite aerial shots of supposed numbers station locations, as if they’d been taken from a surveillance plane or drone.
While working on the project, Bush often found himself behind a computer or radio with few people to share new discoveries with. An emergency helicopter would occasionally hover above his house as it waited for clearance to land at a local hospital, and paranoia ensued. What if someone were listening in on his listening? “I think my housemates at the time felt I was losing it occasionally,” Bush recalled. “They’d hear me at 2 a.m. listening to these weird signals.” Bush’s work culminated in a book of photography and artist’s renderings, Shadows of the State. He had transformed a secretive act of espionage into a work of art and a spectacle accessible to all.
Some enthusiasts speculate that numbers station broadcasts might contain information about a grand conspiracy—an assassination or bombing somewhere—and that uncovering such a scheme could have geopolitical implications. But the truth is that the tedium of everyday life reveals itself even in numbers station broadcasts. When the Cuban Five, a cell of Cuban spies, were arrested for espionage against the United States in 1998, court documents captured the mundanity of their radio transmissions. “Congratulate all the female comrades for International Day of the Woman,” read one message, as reported in the Miami New Times.
And still, the vast majority of broadcasts remain totally unintelligible, leaving space for wild speculation. “The messages are appealing because you can project any fantasy onto them about what they contain,” Bush said.
Even with the clear skies of the Carolina coast giving me reign over the airwaves, I proved an utter failure with my pitiful Radiwow. I realized that if I was to listen in on a secret broadcast myself, I would need to more effectively enlist the help of the internet. I visited Priyom, an online guide created by international shortwave listeners who keep tabs on numbers stations. The home page has a listing of anticipated clandestine broadcasts that spans several days. And at the top, there’s a timer, which counts down to upcoming suspected transmissions. “Next station in fifteen minutes, EO6,” it read. I clicked a link which led me to a software-defined radio site, a web page that lets users listen to radio towers scattered around the globe. The one Priyom directed me to was based in Chongqing, China. It was a Friday night, and as usual, I was perched at the kitchen table, wielding my Radiwow as a backup, just in case. By now, I wasn’t expecting much, but I listened intently with a faint pang of suspense in my gut.
Then came the numbers.
As radio-based conspiracies make a comeback in the coronavirus era, companies like Defender Shield and Vest offer radiation-free baby blankets, headsets, and cell phone cases to cash in on the wave of paranoia. The now-stigmatized tin foil hat has given way to sleeker options, like silver fiber shawls and scarves that double as fashion accessories. Meanwhile, the internet abounds with support groups for “targeted individuals,” people who swear the government is performing secret tests on them through advanced electromagnetic devices. Those theories gained a bit of institutional credibility when, in 2017, the U.S. government expressed concern that an invisible phenomenon was causing brain injuries to its diplomats in Cuba, who had reported disorientation and nausea after hearing strange sonic bursts. Scientists speculated those injuries may have been caused by a weapon that utilized pulsed radio frequencies or ultrasonic signals, while psychologists considered mass hysteria as an alternative possibility.
Although radio paranoia has been common among the general population for decades, Victor Tausk, a psychoanalyst and student of Freud, noticed that fears were particularly acute among people with psychosis, who sometimes believed that a mysterious, unknowable machine was taking control of their minds. The victim almost always believed this machine was operated by a shadowy, sinister group who intended to manipulate or control her, and the components of the machine usually matched whatever cutting-edge technology was taking root at the time. The belief tended to coincide with skin abnormalities and peculiar physical sensations including sexual arousal and electrical tingling.
For James Tilly Matthews, whose schizophrenic symptoms were among the first to be recorded in the early 1800s, the machine was a generator capable of transforming gas particles into condensed streams of magnetic energy. Later, when the radio became the dominant technology of the day, people under the grip of psychosis constructed from its elements new types of mind-reading delusions.
Tausk believed that people who live with psychotic disorders use complex machines and invisible forces as a stand-in for their own deteriorating and fragmenting minds. But the mystery device is not only a reflection of themselves; it also mirrors the ills of the society they live in. “Rather than being estranged from the culture around them, psychotic subjects can be seen as consumed by it: unable to establish the boundaries of the self, they are at the mercy of their often heightened sensitivity to social threats,” said cultural historian Mike Jay in an analysis of Tausk’s theory. It is not that people with mental illness had lost touch with reality—it’s that they’d succumbed to it.
At the kitchen table with arms folded and eyes fixed on my laptop screen, I noticed a strand of purple take form against the dark blue backdrop of the online radio emulator. A haunting, mechanical voice emerged from the white noise: “3-6-1, 3-6-1.” This was the identifier I’d been listening for. Next came the sets of five numbers, which contained the message itself. I imagined a spy listening intently for every number, gradually putting the pieces together.
But it was only gibberish to me. I listened until the broadcast vanished into the night and was replaced by familiar hisses and crackles. I had no revelations or epiphanies.
My last chance of making sense of the phantom voices I’d heard was to track down the person who drew me to the numbers station mystery in the first place. If there was anyone who knew what was behind all of the static, it’d be the man who brought numbers stations to the public—the creator of the Conet Project, Akin Fernandez. He’d first come across numbers stations while using the shortwave spectrum to pick up weather transmissions. When he discovered the surreal, droning voices transmitted via clandestine sites, it became his mission to collect every possible numbers station recording. I connected with him via video chat at his home in London. Surrounded by shelves of records and books, he peered into the camera as if looking out onto a wide panorama.
Fernandez told me he’s proud of his outsider status, both as the creator of Irdial, his London-based record company, and as a human being. He holds a peculiar amalgamation of beliefs, among them that the world is exactly as old as specified in the Bible, that Bitcoin could cause a worldwide revolution and that people with a mastery of mathematics will be our future leaders. I did my best to follow his logic and nodded occasionally to show I was listening in good faith, hoping that he’d eventually get to the meaning of numbers stations. But the solution never came. “Whether it’s dummy messages or not, or whatever the purpose is—it’s irrelevant,” he said. After decades of searching, Fernandez seemed satisfied with the idea that he’d never know.
It’s this detachment—this ability to shrug off the unknown—that separates casual hobbyists from obsessive listeners. Those who give meaning to the messages are more likely to pass the threshold into paranoia. Radio conspiracies, of course, are no more outlandish than many religious or political beliefs that pervade human society. But when we are alone in our thoughts, it’s easier to dig in, further and further, until we are lost. A vicious cycle ensues: Paranoia breeds solitude and solitude breeds even more paranoia until the internal logic of our mind no longer resembles that of the outside world.
The sun interferes with radio waves as they arc off the ionosphere, meaning many listeners must stay awake until the early hours of the morning to catch certain stations in real time. It’s a solitary hobby, with listeners largely isolated and sequestered in their homes, alone in the dark. I can picture the zealots, conspiracists and wanderers, surrounded by screens and wires, unraveling a conspiracy that reaches as far as their minds will carry it.
By now, several months after my encounter with E06, I have lost track of my Radiwow. It must be tucked away in some box in my closet, collecting dust, neglected. I can turn it off, even take out its batteries. I can pretend that the numbers stations do not exist. But the radio waves from a thousand unknown stations continue to pass through it. They are there, even when I’m not listening. A subliminal tension occupies my mind. I know that at any moment, I can blow off the dust from the tiny LCD screen, extend the wobbly silver antenna and sink again into the static. ▩