AR Apple, Mac

The Mac and digital ham amateur radio

Andrew Woodward
FreeDV on the Mac (Courtesy Peter Marks)

The Mac is perfectly positioned to be at the forefront of the increasing use of digital modes in amateur radio on shortwave. 

The Mac has been used extensively over the years for FT8, FT4, WSPR and more, thanks to the open-source program WSJT-X. The Mac version is updated in parallel with the Windows and Linux versions. You can also do digital modes on the Mac through SDR Control for Icom, Yaesu, Kenwood, Elecraft and Flex radios. 

Most modern radios provide digital audio in and out as well as rig control through IP networking or USB cables. Those with older radios can connect to their Macs via Digirig. 

Digital radio’s promise is clear voice transmissions that cut through the noise. Data transmissions can do the same on even low power.

There’s been a bit of work done over the past seven or so years on digital radio for voice on HF with M17 and FreeDV. In short, M17 is a hardware-based approach. FreeDV is a software-based approach. This video is a good overview of FreeDV. It should be noted that FreeDV can also be built into radios. 

The starting point for digital radio on the Mac is WSTJ-X, covering a range of modes with FT-8 and WSPR being most popular. In basic terms, FT-8 sends a signal out and, if picked up, the other end (another ham amateur operator) can engage in a set of short automated messages with your computer (via your radio). WSPR throws out your signal around the world with a digital ID, which other radios and computers log and report online. WSJT-X is a well-established or mature program for popular digital radio modes and works well on the Mac and via SDR Control. A great companion program for WSJTX-X is GridTracker, which, in short, is a ‘human face’ for a fairly clunky WSJT-X program. Its primary benefit is that it automates logging to your logging service, amongst many other things.

Next up is JS8Call. It began before the COVID-19 pandemic and has developed a small but enthusiastic following. It is similar to a phone messaging program, such as SMS, but for radio. The person behind JS8Call continues to call it an “experiment”. But it works and it’s on the Mac. 

The program garnering increasing attention is FreeDV, a program that uses a computer to digitise voice for transmission over HF via your radio. Within FreeDV, there are several modes, including RADE, which is creating excitement due to its functionality and quality. And again, it’s on the Mac.

Finally, for many of these digital programs, the clock on your Mac has to be super accurate to ensure it and the radio are taking and listening when the rest of the world is too. A way to keep your Mac clock synced more often than Apple provides for is via ChronyControl.

Anyone interested in any of these forms of transmission will find no shortage of support through Reddit, Facebook Groups, Groups.IO and Radio Reference.

WSTJ-X

Gridtracker

JS8 Call

FreeDV

ChronyContol

13 September 2025