The Sounds Of The World, One Random Album At A Time

In the streaming era it’s easy to forget that there’s still a lot of stuff being broadcast over the radio for anyone who cares enough to dial in their receiver. Give me an antenna big enough and a tower on which to place it, and I shall listen to the world.

Of course, so you can’t actually listen to everything being blasted out all over the planet yourself. But if you’d like to at least have a little taste, check out Impermanence Series A — a project by [Sam Scorsby] that randomly combines bits and pieces of audio pulled down from shortwave and FM broadcasts with some web streams, live microphones, and even a bit of the Internet Archive each day into a one of a kind album. We’re not sure we’d call it music, exactly. But it’s certainly fascinating to listen to, a bit like randomly spinning the dial on a planet-wide radio receiver.

[Sam] has shared the Python scripts that pull together each day’s album, and he’s not shy about the fact that the project was created with the help of artificial intelligence tools. In fact, that’s sort of the point. [Sam] puts himself somewhere in the middle when it comes to the current debate over AI, and acknowledges that while computers are good at processing raw data, it still takes a human touch to put it all into context.

So each day [Sam] will listen to the latest computer-generated album and pick his favorite tracks, and once the project has run its course, he’ll put together a human-curated “Best Of” collection. Man and machine working together, each doing what they do best.

We know something of opinionated folks on the Internet, and our experience tells us that Impermanence Series A is unlikely to change anyone’s minds when it comes to AI. But we do appreciate the thoughtful approach [Sam] has taken with the project, and look forward to hearing what he comes up with in the end.

Another Radio On A Chip Design

It used to be a rite of passage to build some sort of AM radio receiver. Many people started with a crystal radio, of course, but you’d graduate to maybe a TRF or superhet design. FM radio projects were not as common, because demodulating an FM signal was harder, as was making things work in the 100 MHz range. These days, though, you can get everything on a chip like the TEA5767, and [turtushig22-blip] has an open design that uses that device on a breakout board, a display, a knob, and an external amplifier. An ESP-32 pulls it together. You can see two videos about the project below.

Unlike older FM radio designs, the TEA5767 doesn’t require any adjustments. RF goes in, and stereo audio goes out. You can control the device through I2C or a 3-wire serial interface.

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Positioning Without Satellites Or Base Stations

We’re all used to satellite navigation systems such as GPS or GLONASS, sheer magic in which the combination of a set of reference transmitters and super-accurate timing information can be used to calculate a position to an astounding precision. They had land based predecessors such as LORAN and Decca Navigator which worked in a similar fashion but with fixed land-based reference transmitters. Terra is an attempt to do the same thing without a network of dedicated transmitters, instead using FM broadcast transmitters as its fixed points.

This might seem like an impossible task without access to the transmitters, but they have a workaround using the Internet as a backhaul. Instead of transmitting their timing information like the systems mentioned above, they rely on a set of reference receivers sharing it online to the client’s receiver software. So far they have a demo running in Denver.

The interesting thing about this system is that it’s open-source, and requires only a relatively inexpensive software defined radio receiver and a computer to operate. Now anyone with a group of internet-connected friends to set up reference receivers can have their own positioning system, it’s no longer the exclusive preserve of governments. We like this idea, and we look forward to seeing it being tested more widely.

If you’d like to know where we’ve come from, we’ve taken a look at LORAN before.

Custom FM Radio Station Powered By Shell Scripts

[Trwmato] wanted to spend more time listening to a normal radio to cut back on phone use. But the programming wasn’t quite right so, of course, the solution was to spin up a custom radio station!

The station in question uses a Pi Zero to poll podcasts and news from RSS feeds and automatically mixes them with local content and sends it out via Bluetooth. An FM transmitter allows it to still work on the FM radio, too. Grabbing podcasts isn’t very difficult, thanks to podget. The real logic is in how long to retain things and creating a playlist that both prioritizes fresh content while not repeating things too often. Did we forget to mention the whole thing is a collection of shell scripts?

We could see this as the start of a cool project to have a “radio station” for a school, organization, or company. It is easy to understand and modify.

We often argue that the much-maligned bash script is sometimes the right tool for the job. You can even do things like critical sections in them.

BASICODE: A Bit Like Java, But From The 1980s

Those of us ancient enough to remember the time, or even having grown up during the heyday of the 8-bit home computer, may recall the pain of trying to make your latest creation work on another brand of computer. They all spoke some variant of BASIC, yet were wildly incompatible with each other regardless. BASICODE was a neat solution to this, acting as an early compatibility standard and abstraction layer. It was essentially a standardized BASIC subset with a few extra routines specialized per platform.

But that’s only part of the story. The BASICODE standard program was invented by Dutch radio engineer Hessel de Vries, who worked for the Dutch national radio broadcaster Nederlandse Omroep Stichting (NOS). It was designed to be broadcast over FM radio! The idea of standardization and free national deployment was brilliant and lasted until 1992, when corporate changes and technological advancements ultimately led to its decline.

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TDA7000 die shot, with labels. Credit: Ken Shirriff

Reverse-Engineering The TDA7000 FM Radio Receiver IC

A wristwatch featuring the TDA7000 FM radio receiver IC. (Credit: Philips Technical Review)
A wristwatch featuring the TDA7000 FM radio receiver IC. (Credit: Philips Technical Review)

During the 1980s a lot of consumer devices suddenly got a lot smaller as large-scale integration using semiconductor technology took off. This included radios, with Philips’ TDA7000 FM radio receiver IC being the first to cram most of what you’d need for an FM radio receiver into a single chip. Recently, [Ken Shirriff] had a poke at analyzing a die shot of the TDA7000, reverse-engineering its functional blocks. How did the Philips engineers manage to miniaturize an FM radio? [Ken] will show you.

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FM Transmitter Remotely Controlled Via ESP32

Imagine you’ve got an FM transmitter located some place. Wouldn’t it be mighty convenient if you could control that transmitter remotely? That way, you wouldn’t have to physically attend to it every time you had to change some minor parameters! To that end, [Ricardo Lima Caratti] built a rig to do just that.

The build is based around the QN8066—a digital FM transceiver built into a single chip. It’s capable of transmitting and receiving anywhere from 60 MHz to 108 MHz, covering pretty much all global FM stereo radio bands. [Ricardo] paired this chip with an ESP32 for command and control. The ESP32 hosts an HTTP server, allowing the administration of the FM transmitter via a web browser. Parameters like the frequency, audio transmission mode, and Radio Data Service (RDS) information can be controlled in this manner.

It’s a pretty neat little build, and [Ricardo] demonstrates it on video with the radio transmitting some field day content. We’ve seen some other nifty FM transmitters over the years, too. Video after the break.

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