Digital Modes

Copyright © 1999-2011 by Harold Melton, KV5R. All Rights Reserved. Feel free to link.

How-to: Amateur Radio Digital Modes: Page 1

Getting Started

In this article, we explore the fascinating world of HF digital communications. Nowadays, there are many digital modes that do not need an expensive interface or modem. Broadly speaking, it works like this: you buy or build a relatively simple interface to connect your transceiver’s audio to your computer’s audio, then you install some nice software that does all the work of sending and receiving the various digital modes.

The computer and software may also control the radio’s PTT line, and with a little more complex interface (and a radio with computer-control capability) it can also run most of the radio’s front-panel functions. Thus, the transceiver becomes an RF “back-end” for the computer and everything is done with the keyboard, screen, and mouse.

Most of the digital modes are teletype, and using them is like simplex keyboard chat. Other modes can send and receive color pictures, fax, and other types of data. Still others are specialized for extremely weak signals, such as moon-bounce.

One of the neatest things to come along in a long time is PSK, or Phase-Shift Keying. It’s neato because it can provide a good copy with very low power and narrow bandwidth. With just a few watts and a narrow

There is more to digital modes that just the interface and software. We will also explore the various modes in some detail, as well as operating practices and commonly-used frequencies. So let’s get started!


3 thoughts on “Digital Modes
  1. Hello, I have successfully connected my IC706Mk2G with a Digirig sound adapter and their pre-made 706mk2G capable adapters for Audio and ACC/CI-V and it works. All you need is a decent, shielded (and ferrite protected) USB-C USB cable. Connects to my old MacBookPro and my Raspberrypi4 for digi modes. Make sure you configure the radio in the settings properly (POWERON+LOCK button). If you have weird issues add more ferrites on cables 🙂 Good luck and 73 de VE2LRZ

  2. I am trying to find a pre made data cable that will connect between the Icom 706 round data port and a USB connector on the other end that will allow me to connect my Icom 706 for data operations, to my Mac laptop.

    • Howdy Bob,
      For the usual “soundcard” modes you need an interface, such as a SignaLink or similar, not just a cable. The interface will contain chips to convert the radio’s CAT data signals and audio to USB. Order for specific radio model. On the 706, that will use the 13-pin din “ACC” jack. The smaller 8 or 9 pin din “data” jack on the 706 is for the old data modems (Kantronics, etc), rarely used now.
      73, –kv5r

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