General Information
The Coquelet modes were designed for the communications of French customs and police authorities. They are similar to the British Piccolo modes.
Usage:
§ Transfer of textual information (mostly encrypted) over HF.
Mode Details
|
|
Item |
Value |
|
Standard |
Modulation |
MFSK |
|
|
Number of tones |
13 |
|
|
Shift (Hz) |
30 |
|
|
Bandwidth (Hz) |
500 |
|
|
Symbol rate (Baud) |
13.3 / 20.0 |
|
|
Alphabet |
ITA-2 / ATU-80 |
|
Demodulator Settings |
Demodulator |
Multitone (MFSK) |
|
|
Tone duration (ms) |
75 |
|
|
TD tolerance (ms) |
1 |
|
|
No. of tones |
13 |
|
|
Tone position type |
Equidistant frequencies |
|
|
Tone distance (Hz) |
30 |
|
Features |
Demodulation |
yes |
|
|
Recognition |
yes |
|
|
Decoding |
yes |
|
|
Automatic Polarity Adjustment |
no |
|
|
Combination with other modems (modem list) |
yes |
|
Tuning |
The tuning frequency is the center of the signal | |
Table 96: Coquelet-13
Figure 34: Coquelet-13 Spectrogram