Date:  September 2022
Amount: $296,760

Software-Defined Radio (SDR) has exploded in popularity over the past decade. While several open source hardware SDR platforms are used for test and measurement by radio amateurs today, none of the existing platforms is capable of serving as a universal radio test instrument.

This grant provides funds for Great Scott Gadgets to produce an open source design for a low-cost universal radio test instrument that can be used in place of several pieces of traditional test equipment. Great Scott Gadgets is a for-profit company with a mission to “put open source tools into the hands of innovative people”, closely aligned with the values of both TAPR and ARDC. Based on Software-Defined Radio (SDR) technology, the instrument will enable a new era of wireless innovation throughout the amateur radio community and beyond. They plan to design and build an open source hardware platform that provides the following functions in one tool:

• spectrum analyzer
• vector network analyzer
• vector signal generator
• vector signal analyzer
• antenna analyzer
• power meter
• frequency counter
• full-duplex SDR transceiver

The end product is envisioned as a handheld instrument capable of providing all of these functions in the field over a wide frequency range from LF to 6 GHz. It will also serve as a general-purpose SDR peripheral when connected to a host computer. Additionally we will produce a lower cost variant that will provide these functions as a peripheral without the handheld user interface. By building a directional coupler into a wideband, full-duplex SDR platform, the team plans to design a single hardware platform capable of serving as every popular type of one-port or two-port RF test instrument. Although the tool will have limited calibration options, dynamic range, and maximum power levels, it is expected to be greatly useful to radio amateurs, researchers, educators, and professionals, providing a low-cost alternative to traditional test equipment and enabling testing in the field where benchtop equipment is difficult to deploy. The community will benefit primarily from publication of the design files and software under open source licenses. Anyone will be permitted to build their own unit in a home electronics lab or manufacture and sell units commercially.

Great Scott Gadgets does not plan to patent any technology developed in this project. In the event that there is a change in approach to pursue patents, any patent resulting from this effort will be assigned to TAPR and licensed under CERNOHL-P v2. Like all Great Scott Gadgets and TAPR projects, this project will be entirely open source and developed with an open process. Hardware designs will be released under the CERN-OHL-P v2 license, and software will be released under the BSD-3-Clause license or another OSI-approved license. Documentation will be publicly accessible and published under an open content license. Development repositories will be hosted on GitHub and will be accessible by the public throughout the entire project duration and beyond.