DIGITAL RADIO
Both digital voice and digital data modes are used in amateur radio.
Digital voice modes transmute speech into data form usisng voice encoders (vocoders) before transmitting it. Advanced Multiband Excitation (AMBE) technology is utilized by most digital voice systems. The AMBE vocoder significantly reduces the bandwidth of the digital representation of the voice transmissions.
Common Digital Voice Protocols:
D-STAR (Voice) - Open specification with proprietary vocoder system available from Icom, Kenwood, and Flex Systems.
DMR – The term DMR comes from “Digital Mobile Radio”. In addition to its use in amateur radio, DMR is also used by commercial entities and public safety services. Time Division Multiple Access (TDMA) technology is utilized.
System Fusion – A Yaesu proprietary system using C4FM 4-level FSK (4FSK) Technology
Digital data modes provide for enhanced security, better range, weak signal functionality, automatic logging, and the ability to transmit a large amount of data in a short period over a very narrow bandwidth. The most popular digital mode in ham radio and among our Club members today is FT8.
Common Digital Data Protocols:
D-STAR (Digital Data) - A high speed data-only mode.
Frequency-Shift Keying (FSK) Modes (Several Variations)
FSK441
JT6M
JT65
FT8
Olivia MFSK
JS8
Radioteletype (RTTY)
WSPR
Phase-shift keying:
31-baud binary phase shift keying: PSK31
31-baud quadrature phase shift keying: QPSK31
63-baud binary phase shift keying: PSK63
63-baud quadrature phase shift keying: QPSK63
Packet Radio – (AX25)
Automatic Packet Reporting System (APRS) (See the APRS Page On This Website)
PACTOR (AMTOR + packet radio)
Winlink (Packet, Pactor, Winmor, ARDOP, VARA, and direct between radios)