#Digipan vs fldigi software
Normally, an older computer and a few cables will suffice, and many PSK31 software applications are free and open source. So, once it has been set up to run PSK31, a computer can be used for a variety of digital message transmission modes.Īside from a standard radio transceiver and a computer with a sound card, very little equipment is required to use PSK31. īecause 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, Hellschreiber, and Olivia MFSK. To decode PSK31, the audio whistle received from the transceiver's headphone output is fed into a computer sound card's audio input, and software decodes it. These phase shifts serve the same function as the two tones used in traditional RTTY and similar systems. However, the software rapidly shifts the phase of the audio signal between two states (hence the name "phase-shift keying"), forming the character codes.
This sound is then fed through either a microphone jack (using an intermediate resistive attenuator to reduce the sound card's output power to microphone levels) or an auxiliary connection into the transceiver, from which it is transmitted.įrom the perspective of the transmitter, the sound amounts to little more than somebody whistling into the microphone. When the operator enters a message for transmission, the software produces an audio tone that sounds, to the human ear, like a continuous whistle with a slight warble. Problems playing this file? See media help.Ī PSK31 operator typically uses a single-sideband (SSB) transceiver connected to the sound card of a computer running PSK31 software. Due to the efficiency of the mode, it became, and still remains, especially popular with operators whose circumstances do not permit the installation of large antenna systems, the use of high power, or both. PSK31 was enthusiastically received, and its usage spread rapidly worldwide, lending a new popularity and tone to the on-air conduct of digital communications. Instead of the traditional frequency-shift keying, the information is transmitted by patterns of polarity-reversals (sometimes called 180-degree phase shifts). The 31 baud BPSK modulation system used in PSK31 was introduced by Pawel Jalocha (SP9VRC) in his SLOWBPSK program written for Motorola's EVM radio. PSK31 was developed and named by English amateur radio operator Peter Martinez ( call sign G3PLX) and introduced to the wider amateur radio community in December 1998. This narrow bandwidth makes better use of the RF energy in a very narrow space thus allowing relatively low-power equipment (5 watts) to communicate globally using the same skywave propagation used by shortwave radio stations. PSK31 is distinguished from other digital modes in that it is specifically tuned to have a data rate close to typing speed, and has an extremely narrow bandwidth, allowing many conversations in the same bandwidth as a single voice channel. PSK31 or " Phase Shift Keying, 31 Baud", also BPSK31 and QPSK31, is a popular computer- sound card-generated radioteletype mode, used primarily by amateur radio operators to conduct real-time keyboard-to-keyboard chat, most often using frequencies in the high frequency amateur radio bands (near- shortwave). The green lines indicate a station that is transmitting. A waterfall display depicting several PSK31 transmissions at around 14,070 kHz.
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