Silence Period
All stations using 2182 kHz were required to maintain a strictly enforced three-minute silence and listening period twice each hour, starting at h+00, h+30. This allowed any station with distress, urgent or safety traffic the best chance of being heard at that time, even if they were at some distance from other stations, operating on reduced battery power or perhaps reduced antenna efficiency, as for example from a dismasted vessel. As a visual aide-memoire, a typical clock in a ship's radio room would have these silence periods marked by shading the sectors from h+00 to h+03 and from h+30 to h+33 in green. Similar sectors were marked in red for what used to be the corresponding silence and listening period on 500 kHz between h+15 and h+18 and from h+45 to h+48. These silence periods are no longer required as the introduction of GMDSS has produced alternative automatic watchkeeping systems and the 500 kHz band is no longer in use for maritime traffic.
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Famous quotes containing the words silence and/or period:
“Soon silence will have passed into legend. Man has turned his back on silence. Day after day he invents machines and devices that increase noise and distract humanity from the essence of life, contemplation, meditation.... Tooting, howling, screeching, booming, crashing, whistling, grinding, and trilling bolster his ego. His anxiety subsides. His inhuman void spreads monstrously like a gray vegetation.”
—Jean Arp (1887–1948)
“Remember how often you have postponed minding your interest, and let slip those opportunities the gods have given you. It is now high time to consider what sort of world you are part of, and from what kind of governor of it you are descended; that you have a set period assigned you to act in, and unless you improve it to brighten and compose your thoughts, it will quickly run off with you, and be lost beyond recovery.”
—Marcus Aurelius Antoninus (121–180)