Cw-morse, Dcs selcal – Wavecom W61PC V7.5.0 User Manual
Page 149
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WAVECOM Decoder W61PC/LAN Manual V7.5
Transmission Modes
139
CW-MORSE
The Auto function will automatically detect Morse keying speeds within the range 0 - 90 WPM (words per
minute). The keying speed is continuously updated and displayed.
Parameter
Value
Frequency range
HF
Operation modes
Simplex/Duplex ARQ, Broadcast
Modulation
CARRIER KEYING
Speed
0 - 90 WPM
Receiver settings
DATA, CW, LSB or USB
Input format(s)
AF, IF
The center frequency can be set to any value between 200 and 3400 Hz via the Center item in the De-
modulator menu. The center frequency is nominally 800 Hz which is dictated by the quartz filters of pro-
fessional receivers while other receivers work with 1000 Hz.
The shift can be set between 100-300 Hz and controls the lock-in-range of the center frequency (band-
width = 1.2 x shift).
Using Options | Alphabet the output can be set to Latin, Cyrillic, Greek, Arabic or Hebrew.
Using Options | AFC the continuous automatic tuning to the center frequency of the CW-Morse signal can
be enabled or disabled.
The software reports an error condition (ERROR) if the controlled parameters as the dot-dash ratio, the in-
ter-word or inter-character breaks deviate too much from the standard, and error-free decoding cannot be
maintained.
DCS SELCAL
DCS stands for Digital Coded Squelch (also known as DCSS, Digitally Coded Squelch Signaling), and is
used for selective calls and remote control applications.
Parameter
Value
Frequency range
VHF
Operation modes
Digital Selcal
Modulation
FSK
Symbol rate
133.7,134.4, 137 Bd
Receiver settings
FM, BW = 15kHz
Input format(s)
IF
The data is transmitted on sub audible tones within the frequency range 2 Hz to 300 Hz. In practice, DCS
is similar to CTCSS, but uses 104 octal 3-digit code words instead of continuous analogue tones.
The data is sent as a series of 23-bit GOLAY encoded frames without any sync bits. Polarity can be normal
or inverse, and must be selected by the user.
DCS Code Table
Normal
Inverse
Normal
Inverse
Normal
Inverse
Normal
Inverse
023
047
155
731
325
526
516
432
025
244
156
265
331
465
523
246
026
464
162
503
332
455
526
325
031
627
165
251
343
532
532
343