General Information
ARQ-E is a synchronous dual channel ARQ mode. This system was used by Italian diplomatic services.
Usage:
§ Transfer of textual information over HF.
Mode Details
|
|
Item |
Value |
|
Standard |
Modulation |
FSK |
|
|
Number of tones |
2 |
|
|
Shift (Hz) |
850 |
|
|
Symbol rate (Bd) |
96 |
|
|
Error correction |
ARQ |
|
|
Repetition cycles (char) |
4,5,8 |
|
|
Alphabet |
ITA-2P |
|
Demodulator Settings |
Demodulator |
FSK 2 matched |
|
|
Symbol rate (Bd) |
96 |
|
|
SR tolerance (Bd) |
5 |
|
|
Shift (Hz) |
850 |
|
|
Shift tolerance (Hz) |
20 |
|
|
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 34: ARQ-N
Figure 13: ARQ-N Spectrogram