History
The use of radio to aid in rescuing survivors of accidents at sea came to the forefront after the sinking of the RMS Titanic in 1912. Lifeboats were equipped with spark gap transmitters such as the Marconi Type 241, c. 1920. These operated using Morse code on 500 kHz, the international distress frequency at the time. This frequency had the advantage of long range due to ground-wave propagation and was constantly monitored by all large ships at sea after the Titanic's sinking. However, due to its wavelength of 600 meters, a long antenna was required to achieve good range. Long wires on the order of 1/4 wavelength held up by kites or balloons were often used. Spark-gap continued to be used in lifeboats long after the technology was banned for general communication.
Read more about this topic: Survival Radio
Famous quotes containing the word history:
“History does nothing; it does not possess immense riches, it does not fight battles. It is men, real, living, who do all this.... It is not “history” which uses men as a means of achieving—as if it were an individual person—its own ends. History is nothing but the activity of men in pursuit of their ends.”
—Karl Marx (1818–1883)
“He wrote in prison, not a History of the World, like Raleigh, but an American book which I think will live longer than that. I do not know of such words, uttered under such circumstances, and so copiously withal, in Roman or English or any history.”
—Henry David Thoreau (1817–1862)
“It takes a great deal of history to produce a little literature.”
—Henry James (1843–1916)