Internet access across HF radio

Foundations of Amateur Radio

Internet access across HF radio

In the mid 1980's there was this thing called a Bulletin Board System or BBS. You would connect your computer to a gadget called an acoustic coupler that you would sit next to a telephone. You'd pick up the handset, dial a phone number and wait until there was a squeal in your ear. Then you'd push the handset into the rubber cups on the coupler and watch as your computer started putting characters on your screen.

Now, truth be told, my first foray was the next generation of this, an actual modem where you didn't actually have to touch the telephone, instead, the device could dial on your behalf using so-called AT commands.

And if we're being totally honest, I never actually connected to a BBS. My adventures with global communications started with Usenet News in 1990, but I'm here to make a point, I promise.

Amateur radio is a hobby that is for experimentation. One such experiment is a thing called packet radio. Before you roll your eyes about ancient technology, this gets very cool, very fast.

At its most basic, packet radio is about digital radio communication. Until not that long ago to play you needed a thing called a TNC or a Terminal Node Controller. When I got my license in 2010 I was told that this was a magic box to make digital communication possible between a radio and other radios and amateurs.

Right now, many people are playing with WSPR, Weak Signal Propagation Reporter as well as FT8, both examples of things intended to get specific chunks of information exchanged between two stations. What if I want to chat, or send a file, or a picture?

There are tools like "js8call" which is experimenting with the idea of using FT8 to chat, but what if I told you that there's a better way?

Written by John WB2OSZ, named after a canine that became extinct 9,500 years ago, "direwolf", is software that implements an expensive piece of 1980's hardware, a TNC, that runs just fine on a $5 Raspberry pi. It's been around for over a decade, the oldest date I can find is March 2013 though undated versions before that exist.

It's an example of a so-called software-modem, simple to get started, and it implements the essential pieces of packet radio. It's currently running connected to my radio and I can see packets of information scrolling past. In this case I'm tuned to the local APRS, or Automatic Packet Reporting System frequency of 145.175 MHz.

It's the same information that you can see if you point your web browser at aprs.fi

While that's great, it's just the beginning. Tune to another 2m or 70cm frequency and you can use it to connect to a BBS being run by a local amateur, or, you can tune to a HF frequency and connect to one run somewhere else.

Direwolf also supports a technology called KISS, Keep It Simple Stupid, yes really, developed by Brian WB6RQN, Phil KA9Q, Mike K3MC and others. KISS allows you to connect a modem, like direwolf, to a computer and use technologies like TCP/IP, the primary language of the internet, across a radio link, any radio link.

Let me say that again with different words. You can use your HF radio to browse the internet. No proprietary modes in sight, weak signal, error correction included, all open source, all free, all ready to go.

While we're singing its praises, direwolf can also act as an iGate, an interface between radio and services like aprs.fi, a digipeter that receives and re-transmits APRS data and plenty more.

It gets better.

What if you wanted to use something like RTTY, PSK31, Olivia or some other mode? You could use "fldigi" instead of direwolf since it too supports KISS.

To be fair, there are lots of moving parts here and I've glossed over plenty. This isn't intended to discuss precisely how to do this, rather that it's possible at all and has been for quite some time.

I can't wait to attempt to browse the internet using my radio, for nothing other than the thrill of attempting it.

I wonder if I can do this with Morse Code as the underlying protocol. Only one way to find out.

I'm Onno VK6FLAB