UUGear has released the VU GPSDR, a GPS-disciplined software-defined radio expansion board designed for the Vivid Unit, a palm-sized Rockchip RK3399-based single-board computer with an integrated touchscreen. The board combines an RTL2832U ADC and Rafael Micro R860 tuner with a u-blox NEO-M8N GPS module that provides a disciplined 24 MHz clock reference to its Si5351 local oscillator, delivering frequency stability and timing accuracy typically reserved for much more expensive SDR hardware.
The VU GPSDR covers frequencies from 500 kHz to 1.766 GHz with up to 3.2 MHz of bandwidth, and includes an integrated 108 MHz up-converter for shortwave and amateur band reception below 30 MHz. The board measures 21 x 11 x 1 cm (8.3 x 4.3 x 0.4 inches) and weighs just 65 g (0.14 lbs). Dual rotary encoders allow for software-configurable tuning and volume controls, while the system falls back to an internal TCXO when GPS lock is unavailable.
Connecting the VU GPSDR requires the Vivid Unit Extender, which attaches to the back of the Vivid Unit via GPIO and provides a mini PCIe slot for the SDR board. The Gen 2 Extender adds a CH224K fast-charging controller, quieter blower-type cooling, and screw terminals for external power. On the software side, the board works with GPSDR++, a fork of the open-source SDR++ project optimized for the RK3399's Mali-T860 GPU.
The VU GPSDR is available for $77 (€65), but building a complete handheld SDR system requires the Vivid Unit at $118 (€99) and the Vivid Unit Extender at $33 (€28), bringing the total to approximately $205 (€192) before antennas.
Beyond the bundled GPSDR++ software, the RTL2832U and R860 chipset combination enjoys broad compatibility with Linux SDR applications. Gqrx, a GNU Radio-powered receiver with FFT waterfall display, runs on ARM Linux and supports AM, SSB, FM, and CW demodulation. For utility monitoring, rtl_433 decodes signals from weather stations, tire pressure sensors, and other ISM band devices, with rtl_haos bridging decoded data to Home Assistant via MQTT. Aircraft enthusiasts can run dump1090 for ADS-B reception and tracking at 1090 MHz. The hardware also works with SoapySDR, providing a unified API for integration with GNU Radio and other signal processing frameworks.
