Foundations of Amateur Radio Having a Digital Mode in your shack appears to be a special privilege, at least in some parts of the world. If you'd like to learn all there is to do with using a Digital Mode you need to pay attention and I'll share the secret, it won't take long. If you want to distinguish yourself as a Digital Mode Diva, you need to know that Morse, RTTY, FSK and PSK are digital modes and you must also remember that the bandwidth of a data transmission is dependent on speed and mode. At this point you've covered all the syllabus requirements for holding a Standard License in Australia in relation to operating a Digital Mode. If you want to climb the Mountain of Digital Mode Magic, you need to remember two acronyms, FEC or Forward Error Correction and ARQ or Automatic Repeat Request. You also need to remember four numbers, 31 Hz for PSK31, 250 Hz for RTTY, 730 Hz for Packet Radio and 300 Hz for FSK. And if you want to get really fancy, I should point out that there are several versions of each of these modes and different ways to implement them, so those numbers will change depending on who's teaching you. If I go on to tell you that a Terminal Node Controller or TNC is a black box with two audio leads, one for the microphone and one for the speaker and that you plug those into the appropriate sockets on your radio, you know all that is required to hold an Advanced Certificate in Australia for using a Digital Mode. If you don't want to blow up your radio, then you should also remember that there is a thing called Duty Cycle that will come to haunt you if you get it wrong. That's it, now you know everything there is to know about using Digital Modes. Actually, I'm lying. When you say the letter A on air you use the word Alpha. You're sending extra information so the other end has a better chance of understanding what you said. That's Forward Error Correction. And when you say the same thing repeatedly, like saying CQ, CQ, CQ, if you don't get an acknowledgement from the other end, that's Automatic Repeat Request. Now you really do know all there is to know about Digital Modes according to the syllabus for both Standard and Advanced Licenses in Australia. I'm Onno VK6FLAB