Foundations of Amateur Radio

Every community has its own language. As a member of that community you learn the words, their meaning and their appropriate use. For example, the combination of words "Single Side Band" have a specific meaning inside amateur radio. Outside of radio, those same words are random words with no relationship.

Sometimes a term like "FM" can be heard across many communities with similar understanding, though not identical.

It gets tricky when a word is used widely but doesn't have a common understanding at all. A word like "software" for example.

A question you might hear in amateur radio is: "Can I buy a software defined radio or SDR that has digital modes built-in?"

It's a perfectly reasonable question, the radio runs software, the digital modes are software, so the answer is obvious, right?

What about: "Can the hundred or more computers in my car play Solitaire?"

Aside from the perhaps unexpected fact that your car has computers on board, you most likely know the answer to that. No, since the computers are specialised for different tasks - and if you're driving a Tesla right now, yes, you can play Solitaire, but I'd recommend that you keep your eyes on the road instead.

My point is that not all software is created equal.

The software inside an SDR is essentially doing signal processing, often by several components, each running software, transforming an antenna signal into something, that can be used somewhere else, likely sound.

The applications WSJT-X and fldigi, both software, use a computer running Linux, MacOS or Windows, software, to decode and encode digital modes while providing a way for you to interact with it. Software running on software.

You might well argue that we should be running applications like that directly on our radio and on the face of it that sounds perfectly reasonable, except that to achieve that, you'd also need to build a system to install and update different types of applications, so you could run SSTV, APRS, RTTY, PSK31, FT8 or any of the other hundreds of digital modes and new ones as they are developed.

If you did that, you'd also have to provide a way to manage the operating system, to connect to the Internet and provide security. You'd need to develop a user-interface, perhaps a keyboard and mouse solution, a screen, etc.

Before long you'll have developed a whole computing infrastructure, much like the one we already have in the form of the computer on your desk or the phone in your pocket.

Computers are getting faster and faster every day. This allows for the software on them to become more and more complex. The inter-dependencies are increasing by the second, but that doesn't mean that specialisation isn't useful.

A software defined radio likely has a Field Programmable Gate Array, an FPGA on-board that is great at processing data in streams. It too runs software. Your microwave is running software, as is your television, your smart-watch, your battery charger, the gearbox in your car and your electric tooth brush.

Making a distinction between the various types of software is helpful to understand what is possible and what is not. Being a computer nerd, I must point out that I've only barely scratched the surface of software here, in-case you're curious, microcode, firmware, hardware abstraction, the rabbit hole goes very deep.

Not all software is created equal and every now and then it's a good idea to remember that when you talk about a word in one community, it might mean a completely different thing in another and sometimes the distinction is significant.

As for having an SDR that runs WSPR, no. You can transmit from a computer though, but that's a whole other thing.

I'm Onno VK6FLAB