A remarkable demonstration was given by Amalgamated Wireless recently of a radio transmitter invented and designed by the Company and manufactured in Australia, for sending out distress signals from small coastal vessels not equipped with wireless. The device is known as the Automatic Wireless Distress Transmitter, and is contained in a cabinet 3ft. 6in. High by l5in. square; it is thus easily placed in the chart room of even a small steamer.
In a moment of emergency the captain or any member of the crew, by operating a switch, causes the appliance to send out the International Alarm Signal, followed by the S.O.S. Within 30 seconds any person, though completely ignorant of wireless or of the Morse Code, can transmit an arrangement of letters which causes the position of the ship-latitude and longitude in minutes and degrees-to be transmitted.
The signals may be picked up by any vessel equipped with wireless, and, without any attention, the transmitter continues for 20 minutes to send out the distress signals together with the name of the ship and her position.
By winding a spring the device will continue in action for another 20 minutes if required, and as long as the spring is kept wound up, the transmitter will work continuously for 10 hours before the battery is run down.
An arrangement is also available by which a signal can be transmitted indicating that no further help is required.
There are 168 vessels in the interstate trade on the Australian coast, none of which is fitted with wireless, the chief reasons being the cost of maintaining an operator and the value of the space necessary for his accommodation. The Automatic Wireless Distress Transmitter occupies practically no space yet meets all the requirements of the ordinary small coasting vessel, several of which have foundered within recent times without even being able to send out a message stating the cause of the disaster.
The device has been tested by the Commonwealth Navigation Authorities and the signal has been received by shipping and. land stations on 7,272 occasions and for distances up to nearly 2,000 miles, although the actual range of the transmitter is nominally 100 miles. It is understood that the Navigation Authorities regard the Automatic Distress Transmitter as generally satisfactory.
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