General Information
The Coquelet modes were designed for the communications of
French customs and police authorities. They are similar to the British Piccolo
modes.
Coquelet-80 is the extension of Coquelet-8 by FEC.
Usage:
§ Transfer of textual information (mostly encrypted) over HF.
Mode Details
|
|
Item |
Value |
|
Standard |
Modulation |
FSK |
|
|
Number of tones |
8 |
|
|
Shift (Hz) |
26.67 |
|
|
Bandwidth (Hz) |
300 |
|
|
Symbol rate (Baud) |
13.3 / 26.7 |
|
|
Alphabet |
ITA-2 / ATU-80 |
|
Demodulator Settings |
Demodulator |
Coquelet |
|
|
Tone duration (ms) |
37.5 |
|
|
TD tolerance (ms) |
2 |
|
|
No. of tones |
8 |
|
|
Tone spacing (Hz) |
26.67 |
|
Features |
Demodulation |
yes |
|
|
Recognition |
yes |
|
|
Decoding |
yes |
|
|
Automatic Polarity Adjustment |
yes |
|
|
Combination with other modems (modem list) |
yes |
|
Tuning |
The tuning frequency is the center of the signal | |
Table 99: Coquelet-80
Figure 35: Coquelet-80 Spectrogram