General Information
Packet radio is a complex data transmission system used by radio amateurs. Packet radio networks use the AX.25 data link layer protocol, derived from the X.25 protocol suite and designed for amateur radio use.
Usage:
§ Data communication over HF.
Mode Details
|
|
Item |
Value |
|
Standard |
Modulation |
FSK |
|
|
Number of tones |
2 |
|
|
Shift (Hz) |
200 |
|
|
Bandwidth (Hz) |
500 |
|
|
Symbol rate (Bd) |
500 |
|
|
Coding |
NRZ |
|
Demodulator Settings |
Demodulator |
FSK 2,3,4 discr. |
|
|
Symbol rate (Bd) |
300 |
|
|
SR tolerance (Bd) |
5 |
|
|
Modulation order |
2 |
|
|
Shift (Hz) |
200 |
|
|
Shift tolerance (Hz) |
10 |
|
|
Modem type |
Synchronous |
|
|
Min. burst length (s) |
0.500 |
|
|
Max. burst length (s) |
10.000 |
|
|
Min. pause length (s) |
0.180 |
|
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 150: Packet 300
Figure 52: Packet 300 Spectrogram