uSDXn V1 is an open-source 40m QRP transceiver project designed for experimentation, education, and amateur radio development.

The uSDXn V1 Combined PCB integrates the two main sections of the modular design — the Controller and the Analog Core — onto a single PCB. This version provides a complete board implementation while maintaining the same functional architecture used in the separate modular PCBs.

The Controller section is based on an Arduino Nano / ATmega328P and provides frequency control, LCD display, rotary encoder, push buttons, PTT, CW key input, and control of the Si5351 frequency synthesizer.

The Analog Core includes the RF, mixing, filtering, transmitter, power supply, and audio sections. The design uses the Si5351, FST3253, 74ACT00, LM4562, LM386, and BS170 devices.

The first hardware release uses through-hole components to make the project accessible to builders, experimenters, and students.

The project is intended as an educational and experimental platform. Builders can study the circuit, build the hardware, modify the design, test different approaches, and develop their own versions.

The complete project documentation, schematics, BOM files, firmware, and manufacturing files are available through the uSDXn project repository on GitHub.

GitHub:

https://github.com/wj6c/uSDXn

Community discussion, experimentation, troubleshooting, and project updates are available through the uSDX Community Facebook group:

https://www.facebook.com/groups/uSDXQrp

Open Hardware License: CERN-OHL-P-2.0.