International distress frequency

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An international distress frequency is a radio frequency that is designated for emergency communication by international agreement.

History[edit]

For much of the 20th century, 500 kHz was the primary international distress frequency. Its use has been phased out in favor of the Global Maritime Distress Safety System.

Use of some distress frequencies is permitted for calling other stations to establish contact, whereupon the stations move to another frequency. Such channels are known as distress, safety and calling frequencies.[1]

Satellite processing from all 121.5 or 243 MHz locators has been discontinued. Since February 1, 2009, the U.S. Coast Guard only monitors distress signals from emergency position indicating radio beacons that broadcast using digital 406 MHz signals.[2] Digital 406 MHz models became the only ones approved for use in both commercial and recreational watercraft worldwide on January 1, 2007.[3]

Current frequencies[edit]

International distress frequencies, currently in use are :

  • 500 kHz is still monitored[citation needed] but as of 2010 has ceased to be used as the primary distress calling frequency at sea
  • 2182 kHz for medium range maritime voice use. The US Coast Guard has said "beginning August 1st, 2013 the Coast Guard would no longer monitor 2182 kHz",[4] as have many other coast guard services.
  • Several HF maritime voice frequencies exist for long-distance distress calls:
  • 406 MHz to 406.1 MHz is used by the Cospas-Sarsat international satellite-based search and rescue (SAR) distress alert detection and information distribution system

Digital Selective Calling frequencies[edit]

Several maritime frequencies are used for Digital Selective Calling (DSC), and they are also monitored for DSC distress signals:

  • 2,187.5 kHz[5]
  • 4,207.5 kHz[5]
  • 6,312 kHz[5]
  • 8,414.5 kHz[5]
  • 12,577 kHz[5]
  • 16,804.5 kHz[5]
  • 156.525 MHz Marine VHF radio Channel 70

Amateur radio frequencies[edit]

  • Emergency Centre of Activity (ECOA) frequencies informally established by the International Amateur Radio Union regional organizations (frequencies shown in kHz):
Region 1[6] Region 2[7] Region 3[8]
3760 3750 or 3985 3600
7110 7060, 7240 or 7290 7110
14300 14300 14300
18160 18160 18160
21360 21360 21360
  • Emergency/Disaster Relief Interoperation Voice Channels of the amateur radio Global ALE High Frequency Network: 3791.0 kHz USB, 7185.5 kHz USB, 10145.5 kHz USB, 14346.0 kHz USB, 18117.5 kHz USB, 21432.5 kHz USB, 24932.0 kHz USB, 28312.5 kHz USB.[9]
  • CB -Radio (citizens band) Emergency channels 9 (27.065 Mhz AM) and also 19 (27.185 Mhz FM)

See also[edit]

References[edit]