Elektor has built and published a lot of radio receivers over the years. Back in 2007 we published a project for a software defined radio (SDR) with a USB interface. With this circuit you could receive radio signals over a wide frequency range, with demodulation performed by software running on a PC. The design was enormously popular, but the PLL chip used in the original design has unfortunately been discontinued.
Now we have updated the previous design to create a new version in the form of an Arduino shield. The key component of this relatively simple circuit is the Silicon Labs SI5351 CMOS clock generator, which communicates over the I²C bus and has a frequency range of 8 kHz to 160 MHz.
Simply plug the shield into an Arduino Uno, program the Arduino with the software provided by Elektor, connect a length of wire to the antenna input, and connect the Arduino to your PC. Then you can spend hours listening to radio stations from 150 kHz to 30 MHz. View the video to see how easy it is and learn about the variety of settings available in the SDR software for processing the received signals in many different ways.