The Digital Domain of Amateur Radio

 

The digital side of amateur radio allows data to be sent over the airwaves. With your computer, your radio, and appropriate cables, you can hook the two together and communicate to others - No other special hardware necessary, although if desired, it can be optional.

There are a number of digital modes that grace the airwaves these days. Some of the modes are intended for the lower HF bands, where communication can be made over longer distances. Others are intended for local areas, using VHF and/or UHF frequencies, but can be extended over longer distances using digital repeaters, or digipeaters.

Some of the digital modes can be done with just your computer and radio - using the computer's sound card to receive and decode the bits of information from audio to data. All that is needed to use sound card modes is audio cables between your radio and sound card, and a cable hooking up to either the serial or parallel port on your computer to handle the PTT on the radio. You can use plain old cables, or there are a number of companies that make interfaces to simplify hookup - Hook common cables to an interface box, and plug the box into your radio. Some of the interfaces will reduce the audio output a small amount, allowing a clean audio signal to go between the radio and the computer, and vice versa. Common sound card only modes are PSK-31, SSTV, and others.

Some modes can be done with both your sound card, or with external hardware. With today's faster computers, the sound card has become a viable option for receiving audio from the radio and processing it. However, for those with older computers, or even standalone digital stations (BBS'es, nodes, digipeaters, etc.), hardware is needed to process the audio and turn it into data. Some of these modes include standard AX.25 packet radio, RTTY, and more.