40 .which frequency in the medium frequency band is used for distress and safety traffic by radiotelephony?
A: . 2182kHz
B: .518kHz
C: 6090kHz
D: 2614kHz
A: . 2182kHz
B: .518kHz
C: 6090kHz
D: 2614kHz
举一反三
- . Which of the following frequencies is as international distress and safety frequencies on MF for radio telephone? A: 2187.5 kHz B: 2174.5 kHz C: 2182kHz D: 2177. OkHz
- 以下( )不是国际NAVTEX广播频率。 A: 490 kHz B: 518 kHz C: 4209.5 kHz D: 486 kHz
- Which of the following frequencies is not used for DSC service A: 829lkHz B: 8414.5 kHz C: 16804.5 kHz D: 4207.5 kHz
- All of the following are DSC watch-keeping frequencies, except( ) A: . 2187.5 kHz. B: 2182 kHz C: 12577 kHz D: 6312 kHz
- ________是无线电话遇险与安全通信频率。 A: 2187.5 MHz B: 2187.5 kHz C: 2182 KHz D: 2174.5 kHz