maritime radio silence clock

In Order to increase safety of life, all maritime stations keeping watch on authorized bands should watch international distress frequency for 3 minutes twice an hour on 500 KHz. Radio telephony silence period is for 5 minutes.

Radio telegraphy silence periods : 15 to 18 and 45 to 48 minutes every hour on 500 KHz

Radio telephony silence periods : 30 to 35 and 00 to 05 minutes every hour on 2182 KHz