Wavecom W74PC V8.7.0 - Manual (Page 266)

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Transmission Modes WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V8.7.0
TWINPLEX
TWINPLEX (F7B) is a FSK modulation technique with four modulation frequencies. Two transmission chan-
nels V1 and V2 are obtained through a combination of the modulation frequencies.
SITOR-TWINPLEX systems employ the second channel to double the data transmission rate from the
equivalent of 50 Bd to 100 Bd. The V1 and V2 channels each contain 3 telegraph characters from the SI-
TOR alphabet.
Parameter Value
Frequency range HF
Operation modes Simplex ARQ
Modulation 4FSK
Symbol rate 100 Bd, variable 30-650 Bd
Receiver settings DATA, CW, LSB or USB
Input format(s) AF, IF
Additional Info SITOR Alphabet
Twinplex transmissions can have widely varying shifts. Seven standard combinations are available from
the Shift item of the Demodulator menu:
 100-100-100 Hz
 200-400-200 Hz
 170-170-170 Hz
 115-170-115 Hz
 200-200-200 Hz
 115-170-515 Hz
 65-170-65 Hz
In addition, any desired combination may be programmed.
In addition to shift variations, Twinplex systems may utilize very different keying assignments. On the V1
and V2 channel the software allows the selection of Y-Y-B-B, Y-B-Y-B, B-Y-Y-B, B-Y-B-Y, Y-B-B-Y settings