MSK 1200 bauds professional mode is used, in VHF and UHF, by different
services in France: transports, emergency services, in France.
mode is included into the software MULTIPSK by
Patrick F6CTE, there is the
description of this mode and its variants as well as the specifications
coming from his software :
Baud rate :
Modulation : MSK two tones
(« mark » and « space »)
with a shift between tones of 600 Hz (fixed tones at 1200 and 1800 Hz)
Reception mode : phase modulation
Character set : ASCII
characters + ANSI extended characters
Shape of pulse : rectangular
Bandwidth : about 2 KHz
Demodulation : non coherent
Synchronization : automatic using the signal
Detection code : yes on
15 bits + a final parity bit.
Convolution code: it exists one (8,4 code) but seems not
used. However, Multipsk does not decode it.
Interleaving : no
Pmean/Ppeak : 1
Each frame contains 64 bits. 48 of
these 64 bits are used for data (8 bits by character) and 16 bits for
Each packet of frames is preceded by a sequence of 16 bits (0 and 1
alternated) for bit synchronisation.
The first frame of a packet of frames is subjected to a frame
synchronization sequence of 16 bits.
Recommanded frequencies for
1382 (FM or phase modulation)
Avec une fréquence BF à 1000 Hz, fréquence
affichée sur le transceiver:
30-41, 68-88, 132-225, 400-520 Mhz, in France.
86, 152 et 173 MHz are currently used in FM