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500 kHz - 600 m
There is no other frequency in the electro-magnetic spectrum assigned to a special
service than
500 kHz / 600 meters for such a long period. Since the radio conference of
Berlin in 1906 this
frequency was allocated to maritime radio service. It was
in use since that time and served as the
international distress and calling
frequency. It is given to the International Martime Organization (IMO)
and manged
by the International Telecommuncation Union (ITU).
It was used continously in maritime mobile service all over the world. Even in wartimes this
frequency
was used sometimes between the enemies to signal information. The medium wave bands were keyed in
Morse/Gerke code only. This medium wave length frequency was for use for distances of up to approximate
500 miles or even more. This is the area ships are close enough to be of help for a ship in distress.
Radio officers of the former maritime mobile service at shore and at sea undertake
efforts to
establish a UNESCO Cultural Heritage for this extra ordinary frequency.(2005)
In terms of ITU, unfortunately there is no 'museum frequency' defined so far. But with some
goodwill and understanding national state agencies might give 500 kHz and the special protection
band 495 - 505 a 'Normal Frequency' or 'Industrial - Scientific - Medical ISM' status, knowing the
only reason of it is to enable selected station to work on it. It should not allocated to any other service.
Prof. Braun Day, 2010
Read whole 500 kHz story in
Wikipedia in several languages.
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