General Information
FSK 400/500 is a Chinese multi-tone modem.
Usage:
§ Data communication over HF.
Mode Details
|
|
Item |
Value |
|
Standard |
Modulation |
MFSK |
|
|
Number of tones |
4 |
|
|
Tone spacing (Hz) |
400 / 500 |
|
|
Bandwidth (Hz) |
500 / 600 |
|
|
Symbol rate (Bd) |
100 |
|
Demodulator Settings |
Demodulator |
Multitone (MFSK) |
|
|
Tone duration (ms) |
10 |
|
|
TD tolerance (ms) |
0.5 |
|
|
No. of tones |
4 |
|
|
Tone position type |
Equidistant frequencies |
|
|
Tone distance (Hz) |
500 |
|
|
Min. burst length (s) |
2.500 |
|
|
Max. burst length (s) |
3.200 |
|
|
Min. pause length (s) |
1.000 |
|
Features |
Demodulation |
yes |
|
|
Recognition |
yes |
|
|
Decoding |
no |
|
|
Automatic Polarity Adjustment |
no |
|
|
Combination with other modems (modem list) |
yes |
|
Tuning |
The tuning frequency is the center of the signal | |
Table 114: FSK 400/500
Figure 40: FSK 400/500 Spectrogram