Wavecom W74PC V8.7.0 - Manual (Page 269)

WAVECOM Decoder W74PC, W-PCI/e, W-CODE, W-CLOUD Manual V8.7.0 Transmission Modes
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printed in hex format (0xXX) if it is an ATN packet. For XID frames, the parameters IDs are mapped to
their names, and corresponding values are printed as hex. For other frame types, the whole data field is
printed as hex.
It is recommended to decrease the “Gain” manually until locating the bursts first visually in FFT Direct
view with a 48 kHz bandwidth. The polarity should be set also correctly according to the output polarity of
the receiver.
From Options | Display Mode, Valid Frames Only, All Frames or Indicate Errorneous Frames may be se-
lected.
VISEL
VISEL, also known as FEC-12 or YUG-MIL, is a synchronous system. This mode is used by defense forces
in Eastern Europe.
Parameter Value
Frequency range HF
Operation modes Simplex
Modulation FSK
Shift/Bandwidth 300 Hz
Symbol rate 81.3, 120.9, 123.5, 125 Bd
Receiver settings DATA, CW, LSB or USB
Input format(s) AF, IF
Additional Info ITA-2
The unusual baud rate of 120.9 Bd is very typical for this mode. Synchronization is done at the beginning
of every burst transmission. The unencrypted calling sequence with tactical call signs has an autocorrela-
tion of 12 bits and all bits are interleaved. All traffic is encrypted. Occasionally operator chat in plain text
is transmitted.
WEATHER-FAX
A number of stations world-wide transmit weather charts on a regular schedule. During the transmission
of an image a characteristic and easily recognizable audio signal is heard. A specific frequency deviation
may also be seen on a tuning indicator.
Parameter Value
Frequency range HF
Operation modes Graphic Mode, Broadcast
Center frequency 1900 Hz
Speed 60, 90, 120, 180 and 240 RPM, IOC 288 or 576
Receiver settings FAX, DATA, CW, LSB or USB
Input format(s) AF, IF
Most transmitters work with a wide shift (± 400 Hz) and a few with narrow shift (± 150 Hz).