Analog portable shortwave receiver

Radio is fascinating. That technology is a little over a hundred years old and, what a century it was! Pirates challenging the BBC. Number stations transmitting secret messages for all to hear. Religious and political propaganda. Pagers.

Today, radio is used everywhere from smartphones to car keys. Let’s use it to make music!

TLDR;

This is a write-up of my experiments receiving and sampling radio signals. I’ll go over gear, signals and processing that worked for me so far. There is a whole other world of possibilities with transmitting signals, I’ll leave that for some other time.

If you prefer to dive in and explore this world by yourself, here is a video on how to use a WebSDR site.

Watch on MakerTube or YouTube.

Demo

Here’s a jam where I sample some of the common signals you can pick up on a radio or a WebSDR, just to give you a taste:

How to sample

The easiest way to tune into all of those signals is to use a WebSDR. It’s a special kind of website that gives you access to a radio signal captured by a receiver at a certain physical location. Those receivers are set up in all the different parts of the world, usually in areas with good reception.

Another way is to use SDR dongles and software on your own computer to receive radio signals. The popular and affordable option is the RTL-SDR. The upside of using those as opposed to a standalone radio receiver is flexibility. You have access to a wider frequency range and can choose how to demodulate the signals you get.

SDR USB dongle

You can also use standalone gear to listen to the radio without a computer (I know, what a concept!) My favorite ones are analog portable short-wave receivers. They sound great, and the tuning dial can act as an instrument in itself!

The more commonly available digital (aka DSP) portable radios have more features. They can scan the bands and find signals for you. The tuning experience with them is unfortunately not great: rotating the tuning dial mutes the audio for a quick moment.

An important note on using your own gear is it will require a bit of time and patience. Not all frequency bands are active at all times of day. Your location and surrounding electromagnetic noise play a big role. If your antenna is set up on a ground floor in a city, you will have a much harder time tuning into signals than a person on top of a remote mountain! Sometimes you might need to invest in or build gear to improve reception quality. If you are just looking for cool sounds to sample, I’d recommend starting with a WebSDR.

What to sample

Noise, Buzz & Static

Digital portable shortwave receiver

Radio is an excellent source of noise, static, and crackle sounds. I sample those for texture to put low in the mix, or as something to build instruments out of, i.e. via granular or wavetable synthesis.

Sometimes pirates and governments use jammers, aka buzzers – loud, wide-bandwidth signals that prevent anyone from hearing anything on a portion of a band. They are easy to spot on the spectrum, and they are excellent for creating harmonically rich bass oscillators!

Music

This is the least exciting target to sample for me, but it is there if you want it. The easiest to catch are broadcast FM stations. Those signals do not travel far. They are coming from the sites near you. The signals are strong and the audio quality is high. In a way, the opposite of what I’m looking for :)

FM broadcast

Frequency range: 87MHz - 108MHz in Europe see other regions

Modulation: FM

How to receive: SDR, analog or digital broardcast FM receiver

Then there are AM stations on shortwave. They sometimes have music that is outside of the usual European FM programming. The broadcasting sites are further away, so there is interference and fading. All these factors make music played on shortwave a bit more appealing to me.

If you tune into a station and are curious to know what it is, shortwave.live is an excellent website for that.

AM broadcast / Shortwave radio

• Frequency range: short wave is a term that’s used to group together a few of different frequency ranges. They start at around 2MHz (120m) and go up to 26MHz (11m) see details here
• Modulation: AM
• How to receive: SDR, analog or digital shortwave AM receiver

Overall, I find it tricky to use music sampled from the radio unless it’s a sparse instrumental piece. Try it out yourself! Maybe you find it inspiring.

Speech

There’s plenty of news and talk shows on shortwave. And let me tell you, there’s nothing like political or religious propaganda looped over a banging beat!

Another source is amateur radio operators. Hams use different kind of modulation for voice. That means they sound different compared to shortwave radio, and you need another kind of receiver if you are tuning into those conversations.

There’s often a lot of activity on the 40m and the 20m amateur radio bands. People use LSB (lower side band) modulation on 40m, and USB (upper side band) on 20m.

Amateur radio voice modes

• Frequency range: there are a few of them, I’d recommend starting with the 40m band (around 7.16MHz) or 20m band (around 14.15MHz)
• Modulation: LSB / USB
• How to receive: SDR, some digital shortwave receivers, dedicated amateur radio receivers

Yet another group of people you can hear talking on the radio are Air Traffic controllers, police and the fire-department and other professionals. I do not have much experience with those kinds of signals, but it is possible to catch them with an SDR or portable receivers. Keep in mind, in some countries (e.g. the UK) it is illegal to listen in on police and other stations like that.

For music, I don’t process speech samples that much. They sound great over anything! Sometimes, beat repeats, delays, and adjustable loop speeds can help paint those sounds into the broader musical context.

CW / Morse code

Morse code or CW (continuous wave) is still actively used by hams and automatic stations on the air. You will find people using Morse code at the start of every amateur radio band. You can also tune into automatic stations, like beacons that are used to check wave propagation.

CW mode

• Frequency range: start of every ham radio band. For example for the 40m band there is usually activity around 7.02MHz. Every band also has a dedicated frequency used by a wave propagation beacon
• Modulation: CW
• How to receive: SDR, some digital shortwave receivers, dedicated amateur radio receivers

In terms of using it for music, CW is so simple that it is excellent at many things! The audio is a rhythmical sequence of beeps. Do with that what you like – it will sound good! You can even change the pitch by tuning slightly off the signal frequency.

You could also extract triggers or gates from the Morse Code audio and sequence other things!

Digital signals

There is a wide variety of digital signals used in radio. Some sound like noise, some like a dial-up modem. I haven’t used them much as of yet, but I’d like to. They sound great!

Number stations

"Number stations" is a generic term for mysterious transmitters that would sometimes go on the air to read a series of numbers or words that would not make sense together.

They became especially active during the Cold War, and some are still operational. The messages are considered to be an encrypted one-way method of communication with undercover agents around the world.

If you are curious, you can find more information about them online here. There are also a few audio samples on that website.

And here is a schedule of active transmissions.

Pirates!

Not much to say here. There are a lot of pirate radio signals out there! I mean, people that transmit on frequencies they are not supposed to transmit on. Some of those stations are fun, a lot are obnoxious. Try looking for them!

Pirates are not subverting FM broadcast range to promote wild new music genres anymore. Unfortunately. At least none that I could find.

Wrapping up

Radio has been on my mind for a couple of years now. At first, I thought I could use it for projects I’m interested in. Make a radio station that plays local bands. Create an art installation. Talk to people far away without relying on layers upon layers of infrastructure.

It turned out that bringing most of those ideas to life is either illegal or very expensive. When I realized that, I was disappointed. There is a strictly limited set of activities mere mortals can do with a transmitter, all heavily regulated. There is not much space for exploration and experimentation. I was about to abandon the subject, but then I realized something that to this day keeps me curious.

The story of radio is the story of people, power, and resource capture. That resource is limited but widely and easily accessible. It is Radio Spectrum.

That’s why I enjoy listening and sampling transmissions. That’s why those samples I find make music more humane. A lot of that struggle is happening in "a public space" on the radio, and we can listen in on it.

An AM broadcast host trying to change the minds of people they’ve never seen. An amateur radio enthusiast who spends their share of the spectrum just to confirm that they are being heard, that someone else will write their name in a book next to their QTH location and signal report. And if that’s not enough, that amateur gives up their government-assigned ID and takes to... Piracy‽ What‽

How fascinating is that!

Anyway, if you have seen any projects that use radio in an unconventional way to make music, please reach out! I’d love to hear more!

Published on 2025-09-10