When cheap digital TV dongles enabled radio enthusiasts to set up software defined radio (SDR) systems at almost zero cost, it caused a revolution in the amateur radio world: now anyone could tune in to any frequency, with any modulation type, by just pointing and clicking in a computer program. While this undoubtably made exploring the radio waves much more accessible, we can imagine that some people miss the feeling of manipulating physical buttons on a radio while hunting for that one faint signal in a sea of noise. If you’re one of those people, you’re in luck: [Kaushlesh C.] has built a portable, self-contained SDR system with real knobs and switches, called SDR Dock 1.0.
The heart of the system is a Raspberry Pi running GQRX, an open-source SDR program that supports many different RF modules. [Kaushlesh] used an Airspy HF+ Discovery, a compact receiver that can work the HF and VHF bands, but it’s easy to modify the SDR Dock to accept other types like those ubiquitous RTL dongles. A seven-inch LCD screen with integrated speakers forms the main output device, with everything powered by a 10,000 mAh lithium-polymer battery.
All of this is pretty neat already, but the real beauty of the SDR Dock is in its enclosure. It’s a 3D-printed case with a swivelling handle on the side, an antenna connector at the top and a convenient user interface at the front. There are pushbuttons to change device settings, rotary knobs for frequency tuning and volume control, and sliders to adjust things like gains and bandwidths. All of these are read out by an ESP32 which communicates with the Pi through I2C.
As an open-source design, everything is of course fully customizable, from the radio receiver type to the functions of those dials and switches. The simple, user-friendly design should also make it an ideal SDR system for absolute beginners. It’s not [Kaushlesh]’s first portable Pi-based SDR system, however: he’s also submitted a somewhat more hardcore version to this year’s Cyberdeck competition. For those completely new to the SDR game, [Josh]’s video at the 2020 Remoticon is a great introduction.