Building a direct conversion radio receiver
After constructing a regen (regenerative) radio receiver several years ago, Michael LeBlanc decided to upgrade to a direct conversion receiver in order to gain some performance improvements and support both AM and SSB signals. His build is based on a generic design available here, along with a couple modifications by Ryan Flowers, and of course his own experimentation to get things working properly.
The device is controlled by an Arduino, which changes the frequency via an Si6351 oscillator depending on encoder input. Visual frequency feedback is provided by a small OLED display, and the assembly is encased in a very cool 3D-printed enclosure—or rather ‘enclosures’ as two boxes separate the digital and radio/audio circuits.
It’s a simple configuration and the result, as shown in the video below, is a very clean sound!