| |||
| 频率编码信号 | |||
|
frequency- coded : 12 phrases in 6 subjects |
| Air defense | 3 |
| Communications | 1 |
| Electronics | 3 |
| Information technology | 1 |
| Space | 1 |
| Technology | 3 |
| |||
| 频率编码信号 | |||
|
frequency- coded : 12 phrases in 6 subjects |
| Air defense | 3 |
| Communications | 1 |
| Electronics | 3 |
| Information technology | 1 |
| Space | 1 |
| Technology | 3 |