General Information
ARQ-M4-242 is a synchronous full duplex time-division multiplex system designed for low error-rate exchange of textual data between two stations of governmental authorities.
Usage:
§ Transfer of textual information over HF.
Mode Details
|
|
Item |
Value |
|
Standard |
Modulation |
FSK |
|
|
Number of tones |
2 |
|
|
Shift (Hz) |
170 |
|
|
Bandwidth (Hz) |
400 |
|
|
Symbol rate (Bd) |
172 / 192 |
|
|
Alphabet |
ITA-3 |
|
Demodulator Settings |
Demodulator |
FSK 2,3,4 discr. |
|
|
Symbol rate (Bd) |
192 |
|
|
SR tolerance (Bd) |
2 |
|
|
Modulation order |
2 |
|
|
Shift (Hz) |
173 |
|
|
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 28: ARQ-M4-242
Figure 11: ARQ-M4-242 Spectrogram