K4DCG
David Gregory
Elizabethtown, Kentucky
HAM
RADIO
PSK31 (Phase Shift Keying at 31 Baud) is an increasing popular computer-soundcard-generated radioteletype type mode, used primarily by amateur radio operators to conduct real-time keyboard-to-keyboard chat. Because PSK31 has very narrow bandwidth many conversations fit in the same bandwidth as a single voice channel. An additional advantage of this very narrow bandwidth it allows low-power (QRP) equipment (25 watts or less) to communicate globally. Due to the efficiency of PSK, it is especially popular with operators who don’t have a large antenna systems or have higher powered equipment.
PSK31 introduced to the amateur radio community in December 1998. It was developed and named by English amateur radio operator Peter Martinez (G3PLX). Since the release of PSK31 usage has continued to grow worldwide. Today it is one of most popular digital modes.
Aside from a standard radio transceiver and a computer with a sound card, very little equipment is required to use PSK31. With single-sideband (SSB) transceiver connected to the sound card of a computer running PSK31 software.
Most operators now use a commercially available interface/modem device (relative inexpensive) between their computers and radios. Most interfaces now also incorporate their own sound card and can be powered and run from the computer via a single USB connection.
The radio may be interfaced to the computer using acoustical coupling. This coupling involves simply using the computers microphone by holding the radio microphone to the computer speaker to receive the signal. The audio sound received from the transceiver's output is fed into a computer sound card's audio input, and software decodes it. The software displays the decoded text. When the operator enters a message for transmission, the software produces an audio tone that is then fed through the transceiver’s microphone to be broadcast.
The use of PSK31 does not require exclusive use of a dedicated computer. When it is not running the PSK31 program, the computer can still be used for normal activities. There are many software applications available for download and many of these programs are free. Because PSK31 was developed for use through a computer's sound card, many programs have since been created to use the same technology for other modes, such as RTTY, fidigi, and. Olivia MFSK. So, once it has been set up to run PSK31, a computer can be used to explore a variety of digital message transmission mode