GNU Radio

Build amazing, working Ham Radio projects on your computer!

Kevin McQuiggin VE7ZD came to a meeting to present GNUradio. 

What is GNUradio? It is an open-source free software package for all major platforms that represents common radio components as blocks, much like the block diagrams you studied for your basic exam. They are assembled and linked together to form receivers and transmitters, referred to as “flowgraphs” in GNUradio.

A filter in GNU Radio - But you do not need to know the math!

How does it work? Radio signals are always “analog” (electromagnetic waves), of course, so an analog “receiver” is still necessary. This is where a cheap $20 USB dongle comes into the picture. These receivers analyze the electro-magnetic spectrum and immediately digitize it. The “numbers” are then streamed to the digital radio processing chain. The math defines signals precisely: AM, FM, SSB, PSK, et cetera. Math can then process these digitized signals to substitute, with much greater accuracy than analog radios, the various blocks of the receiver including mixers, filters, amplifiers, et cetera, and you don’t need math skills.

As with much radio innovation in history, hams are at the forefront and your imagination can allow building general coverage all-mode receivers, Cell site emulators, Radar transceivers and Aviation applications, to name just a few.

Kevin demonstrated a basic FM broadcast receiver in class and showed a video of contacts he has made with Inmarsat, decoding that satellite's data. He followed up with a Saturday morning workshop that was well attended and everyone came away with a better understanding of the program.

An illustration of a GNUradio filter and an FM broadcast receiver

This is a remarkable program, the operation of which should be within the grasp of any ham with a Basic license.

Kevin has promised an article on GNU radio for an upcoming Communicator... stay tuned.