From Titanic-era disasters to talking with astronauts, the story behind those letters is way more fascinating than you'd think
Every once in a while, a jingle pops into my head completely uninvited, like some kind of audio mosquito. “1-877-KARS-4-KIDS…,” “We are farmers, bum ba dum bum bum bum bump” and one that really lives rent-free in my brain—”101.3 KDWBeeeeeee!” I lived in Minneapolis for years, and I can still sing that call sign for a popular radio station like it’s my personal anthem. And I bet you can sing a few random radio station call signs too. But have you ever wondered WHY your brain is permanently tattooed with a string of letters you never actually meant to memorize? And what’s up with those weird combos anyway—why do radio stations start with K or W? Why not R for radio? Or P for please-stop-playing-that-song-again?
Turns out, it’s not just branding (though it is a pretty genius marketing move). Those “random” radio station names—known as call signs—actually serve a critical function.
“Call signs are a small but incredibly important part of radio,” says Sam Wheeler, a Denver-based ham radio expert. “They identify the operator, reduce confusion, allow for regulation, and help prevent bad behavior—whether it’s accidental interference or someone doing something they shouldn’t, and give everyone a base set of rules to communicate.”
But why are call signs so seemingly nonsensical? So I did what any curious writer would do: spiraled down an FCC rabbit hole and called in two radio experts—Wheeler and fellow radio communication expert Joe Bassett—who casually talk to astronauts in space and once helped coordinate hurricane relief via ham radio. I discovered that there’s actually a lot of sense behind why radio call signs are named the way they are.
Read on to find out everything you’ve ever wanted to know about radio call signs (including the right way to pronounce them).
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Why do radio stations start with a “k” or “w”?
“K” and “W”, along with “A” and “N”, are the letters assigned to radio stations in the U.S. Most commercial radio station call signs use K and W. The N and A prefixes are usually reserved for military and government use. But it wasn’t always this way.
The first practical radio communication system, invented in the 1890s, was developed by Guglielmo Marconi. Through the early 1900s, radio was a Wild West of amateur signals and chaotic call signs. Want to start a station? Cool, just pick some letters or your name and start shouting into the void. It worked great—until it didn’t.
“The Titanic disaster in 1912 was a major wake-up call,” Wheeler explains. “Back then, call signs were informal and had no set structure. The night the ship sank, the Titanic’s crew was overwhelmed with radio messages [in Morse code], and they were having a difficult time telling personal messages from important navigation ones. That confusion contributed to the tragedy.”
In response, international leaders called the 1912 London International Radiotelegraph Convention. Representatives from 37 countries, including Great Britain, France, Germany, the United States, Austria-Hungary, and South Africa, met to assign official radio call signals—and made it clear we needed some standard rules. For starters, people needed to know where the signal was coming from and so countries were given letter ranges to identify themselves. The United States was assigned K, W, N and A, while other nations got their own unique identifiers (for instance, J for Japan, S for Spain).
Today, these prefixes are internationally recognized and governed by what’s now the International Telecommunication Union (ITU). According to Bassett, the founder of Valiant Outfitters, it’s still a little confusing: “Some letters are shared across multiple countries. For example, ‘C’ can mean Canada, Cuba, or Morocco, but additional letters help narrow it down—like CL for Cuba and CF for Canada.”
Eventually in 1928, the Federal Radio Commission, the precursor to the Federal Communications Commission (FCC) took charge of assigning and cataloguing call signs within the US.
What’s the difference between the “k” and the “w”?
The “K” and the “W” are based on the location in the U.S. When the FRC/FCC took over in 1928, they decided to split the country along the Mississippi River. Stations west of the Mississippi would start with a K, while those east of it would start with a W. The choice of which side got which letter appears to be random, but seriously, whose idea was it to use the “W” for East?! I would like a word.
But still, simple enough, right? Well, mostly. There are exceptions.
The rule wasn’t strictly enforced at first, so you’ll still see a few stations that don’t follow it today, Wheeler says. For example, the first officially recognized U.S. radio station chose 8XK which was later changed to KDKA even though it’s in Pittsburgh, which is definitely east of the Mississippi. Meanwhile, WOAI in San Antonio somehow snagged a W even though it’s in Texas. I guess the FCC sometimes just shrugs?
Do the “k” and “w” actually stand for anything?
Nope. Sorry, no juicy acronyms here—K doesn’t stand for “Krazy Kool Karaoke” and W doesn’t mean “We Talk (Too Much).” The letters were chosen arbitrarily by the international agreement.
But here’s a fun fact about one really special radio call sign: NA1SS is the primary call sign for the US side of the International Space Station. “Some radio operators can bounce a signal off the moon, atmosphere or even the international space station itself,” Wheeler says. “Anyone with the right equipment can call them, and all the astronauts are licensed radio operators, and they’ll even chat with you from orbit if conditions are right.”
Let’s pause and appreciate that you can literally call space. With a radio.
How do you get a radio call sign?
The FCC assigns call signs for both commercial and amateur stations. If you’re starting a new station, you apply through the FCC, and they’ll issue you an available set of letters, usually starting with a K or W, depending on your location. And yes, this still applies to digital and online stations, though the process is a little different since they’re not using traditional broadcast frequencies.
The biggest difference between broadcast call signs and amateur (aka ham radio) call signs is the format. Broadcast stations use just letters—think KROQ or WGN. But ham radio call signs include a number in the middle, like KJ4QIR. That number tells you which FCC region the license came from—1 for New England, 4 for the Southeast, 6 for California, and so on.
Ham call signs are usually handed out in order, but Bassett says you can also request a custom one or even get a special one-time call sign for events, like a holiday broadcast or emergency operation.
Why would you, as an individual, want a radio call sign? Both Wheeler and Bassett emphasize how useful this communication skill is. Because radio might seem old-school, but when the Wi-Fi goes out? It’s the original (and possibly only) social network.
Do radio stations have to follow this rule as well?
Yes—and not just because it sounds cool. In the U.S., both commercial radio stations and amateur broadcasters (a.k.a. ham radio heroes) are legally required to get licensed, register their call letters with the FCC, and follow a strict set of broadcasting rules. You can’t just slap on “KLOL” and start yelling about memes into a mic from your garage.
“There’s a regulation that you have to announce your call sign every 10 minutes while on air,” Wheeler says. “It’s not just branding, it’s a legal requirement.” Which explains why your favorite pop station reminds you who they are every five minutes, like a toddler showing off their sticker chart. It’s not narcissism. It’s federal compliance.
How do other countries handle radio call letters today?
While the U.S. uses K, W, N, and A, other countries use their own letter assignments from the International Telecommunication Union (ITU). In Canada, for example, you might hear stations starting with CF, CK, or VO. Japan uses J, and the UK uses G or M. You can see the full ITU list of call signs here, if you’re the type who finds call letters thrilling (welcome to the club!).
These international call signs are more than just bureaucratic red tape, they’re critical for avoiding confusion, especially during emergencies. Bassett recalls, “After Hurricane Maria, my emergency team in Puerto Rico used the call sign K1M—’Kilo 1 Maria’—so other operators knew we were handling disaster communications and would avoid interference.”
There is a right way to pronounce call signs
Think reading out random letters over the air is as simple as “K-D-W-B”? Not quite. There’s actually a right way to say radio call signs—and it involves channeling your inner military comms officer.
“We use the military alphabet, but we pronounce it slightly differently to emphasize certain syllables,” Wheeler says. “For instance, instead of just saying ‘alpha’ the usual way, you’d say ‘alPHA’ to bring out the emphasis and avoid confusion.”
That’s because in high-stakes radio communication—especially during emergencies or in noisy environments—a single misheard letter can throw off the entire message. This is why standardized pronunciation matters, particularly in ham radio, aviation, military, and emergency response.
So the next time you hear someone confidently rattle off “WISS-key TANG-go FOKS-trot,” just know: they’re not quoting a movie, they’re spelling something out the correct way. Now, if we could just get a rule banning morning radio hosts from using an air-horn, everything would be perfect.
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Sources:
- Sam Wheeler, Denver-based licensed radio operator and survivalist; phone interview August 17, 2025.
- Joe Bassett, licensed radio operator, founder of Valiant Outfitters, and author of Emergency Communication 101; email interview August 15, 2025.
- FCC: “Amateur Call Sign Systems”
- FCC: “Call sign reservation and authorization”
- FCC: “A Short History of Radio”
