First allocation of the frequency 500 kHz / 600 m wavelength was made by radio conference
held in 1906 in Berlin. All stations watched this frequency for calling other stations and make
arrangements to work on then different frequencies. It was given an extra ordinary status of
a ' distress ' and ' calling frequency ' and strict rules were set for usage. Operators at sea and
ashore have to observe ' silent periods ' of 3 minutes duration for twice an hour and distress
traffic was handled on this frequency. Coastations announced navigational warnings, weather
reports, traffic lists on it. After the Titanic sinking in 1912 shipping was forced to observe this
frequency constantly by a person with skill in Morsecode recognition.

Upon international agreement an 'auto alarm system ' was put into force. A fixed tuned receiver
watched the 500 kHz for the 'autoalarm signal', a transmission of 12 continous signals, 4 seconds
on, 1 second out. After 4 signals this device makes a bell ring and calls for the operator to tune in
and listen to the emergency transmission. The operator has to write down all he is hearing to the
radio log for later documention. He has to inform the captain at once upon this matter and wait for
his orders. Ship's masters have to decide if they can give assistence to the ship in distress and act
accordingly.

Until the end of manual maritime service to the end of the 1980's it was the 'meeting place' for ships
and coastal station at an range of up to 300 miles and even beyond. With the implementation of
automatic systems this frequency become obsolent and was not in use for about 20 years!

What should be done with this frequency ?