Building a direct conversion radio receiver
July 8th, 2019—
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 as well as support AM and SSB signals between 160m and 20m. His build is based on Ashhar Farhan’s DC40 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 analog circuits.
It’s a simple configuration and the result, as shown in the video below, is a very clean looking and sounding project!