Digital Modes - PSK31 - SSTV - D-STAR
Phase Shift Keying is a digital modulation scheme that conveys data by
changing, or modulating, the phase of a reference signal (the carrier wave).
The simplest PSK technique is called binary phase-shift keying (BPSK).
It uses two opposite signal phases (0 and 180 degrees).
This new mode of transmission was enthusiastically received, and has
since quickly spread into worldwide use. Due to the efficiency of the
mode, it has become especially popular with operators whose circumstances
do not permit the erection of large antenna systems and/or the use of high
Read more about PSK
Slow Scan Television
Slow-scan television (SSTV) is a picture transmission method used mainly
by amateur radio operators, to transmit and receive static pictures via
radio in monochrome or colour.
SSTV is basically facsimile.
And facsimile is a method of producing a picture a line-at-a-time. The more
lines, hence more time taken to send them, creates sharper better defined
Read more about SSTV
D-STAR (Digital Smart Technology for Amateur Radio) is a digital voice
and data protocol specification developed as the result of research funded
by the Japanese government and administered by the
Japan Amateur Radio League (JARL) to
investigate digital technologies for amateur
While there are other digital on-air technologies being used by amateurs
that have come from other services, D-Star is one of the first on-air
standards to be widely deployed and sold by a major radio manufacturer that
is designed specifically for amateur service use.
Read more about D-STAR