mcHF — Open Source HF SDR Transceiver

The mcHF is a fully open source software defined radio transceiver for the HF amateur bands (3–30 MHz). Its goal is planet-wide, off-grid communication — ionosphere permitting — with no dependence on cellular or satellite infrastructure.

Both hardware and firmware build on the work of many radio amateurs. The design is modular, uses mostly off-the-shelf components that can be soldered by hand, and is straightforward to repair when something goes wrong. An amateur radio licence is required to transmit.

Features

• Transmit and receive on the 3–30 MHz amateur bands
• SSB, AM, FM and CW modes
• FT8 and WSPR digital mode decoding (in development)
• Real-time spectrum scope and waterfall
• Large 4.3" IPS LCD with capacitive touch
• 25 W output power
• Built-in 80 Wh lithium battery
• Dual USB-C ports for power, charging and PC connection
• Bluetooth stereo headphone support
• LoRa sub-GHz auxiliary radio

Hardware

The radio is built around an STM32H747XI dual-core MCU: the Cortex-M7 (480 MHz) runs the user interface and system control, while the Cortex-M4 handles the real-time DSP (demodulation, AGC, filtering, spectrum FFT).

Altium PCB project files

Status	Version	Location
Latest	0.9 rev B	pcb/v9
Develop	0.8.5	pcb/v8/mchf
Legacy	0.6.3	pcb/__legacy/v6

PCB gerbers

Revision	Version	Location
rev 8	0.8.5	testing/gerbers/0_8_5
rev 7	0.7.0	pcb/__legacy/bin/v7
rev 6	0.6.3	pcb/__legacy/bin/v6

Repository layout

Directory	Contents
firmware	All firmware projects (see below)
pcb	Altium PCB projects and gerbers
mechanical	Enclosure and mechanical design files
testing	Test data and manufacturing files

Building the firmware

The firmware is developed with STM32CubeIDE (Eclipse CDT managed build — no separate Makefiles).

Clone with submodules (the ST HAL and the FT8 library are pulled in as git submodules):

git clone --recurse-submodules https://github.com/m0nka/mcHF.git

There are three independent firmware projects, each opened separately in STM32CubeIDE:

Project	Core	Location
Application processor (UI, control)	CM7	firmware/app_proc/proj
Baseband DSP	CM4	firmware/baseband
Bootloader	CM7	firmware/bootloader

Open the project's .project file in STM32CubeIDE and use Build → Build Project. The application processor build produces firmware/app_proc/proj/Release/mchf_app_proc.bin, which can be flashed over SWD with program_radio.bat (requires STM32CubeProgrammer).

Previous hardware generations

Older mcHF hardware versions are supported by the community-maintained UHSDR firmware:

• Firmware repository: df8oe/UHSDR
• Project crash course and documentation: UHSDR wiki

Community and contributing

Questions, build reports and development discussion are welcome in the mcHF discussion group.

Feel free to build one yourself and contribute — bug reports, fixes and improvements to hardware, firmware or documentation are all appreciated.

License

mcHF is licensed under the GNU General Public License v3.0.

Copyright © 2013–2026 Krassi Atanassov, M0NKA