General Information
SPREAD 51 is a synchronous FEC system which was used by the Ministry of Foreign Affairs in Romania.
Usage:
§ Data communication over HF.
Mode Details
|
|
Item |
Value |
|
Standard |
Modulation |
FSK |
|
|
Number of tones |
2 |
|
|
Shift (Hz) |
400 |
|
|
Symbol rate (Bd) |
102.7 |
|
|
Coding |
10 Bit Bauer code, Interleaving |
|
|
Alphabet |
ITA-2 |
|
Demodulator Settings |
Demodulator |
FSK 2 matched |
|
|
Symbol rate (Bd) |
102.7 |
|
|
SR tolerance (Bd) |
1 |
|
|
Shift (Hz) |
400 |
|
|
Shift tolerance (Hz) |
10 |
|
|
Modem type |
Synchronous |
|
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 204: SPREAD 51
Figure 70: SPREAD 51 Spectrogram