commiinications. With the increasing use of radio comniunications 

 by maritime interests there has been a crowding of commercial 

 frequencies which has interfered somewhat with the reception of 

 ice patrol bulletins in the Grand Banks area. Studies are being con- 

 ducted with the experience of the 1950 season in mind so that future 

 broadcasts will be heard by a maximum number of ships with a mini- 

 mum amount of interference because of crowded frequencies and con- 

 flicting schedules. 



Scheduled broadcasts of the NIK ice bulletins were sent out twice 

 daily during the 1950 season at 0118 and 1318 G. C. T. These times 

 had been selected so that a maximum amount of recently received 

 information could be included. The morning broadcast included a 

 digest of ice reports received during the night while the evening 

 broadcast included the ice sighted by the aircraft. The purpose of 

 choosing the times 0118 and 1318 G. C. T. was to have the broadcast 

 start immediately after a silent period and thus reduce the number of 

 interruptions which would be occasioned by silent periods, and also 

 to allow the broadcasts to be completed during the hours when the 

 operators in single-operator ships would be on watch. 



In 1950, the A2 emission on 480 kilocycles and the Al emission on 

 8,425 kilocycles were keyed simultaneously. Each broadcast was 

 preceded by a general call on 500 kilocycles after which the transmit- 

 ting station (Coast Guard Radio, Argentia) announced the NIK ice 

 bulletin with the operating signal to shift to 480 and 8425 kilocycles. 

 Following the shift there was a 30-second period of test signals to 

 permit receiver tuning. The ice bulletin was then broadcast twice, 

 the first transmission being made at 15 words per minute and the 

 second transmission at 25 words per minute, with a 2-minute interval 

 between transmissions. The following daily schedule of ice broad- 

 casts was maintained from 1318 G. C. T. on 6 March until 1318 

 G. C. T. 26 June. 



Frequency 

 Time (G. C. T.) (kilocycles) Emission 



0118 480 A2 



0118 8425 Al 



1318 480 A2 



1318 8425 Al 



Constructive criticisms and comments from personnel of ships 

 operating in the area have been a great help in the past and further 

 suggestions are always welcome. Suggestions should be addressed to 

 the Commandant, United States Coast Guard, Washington 25, D. C. 

 It is reiterated that the successful functioning of an ice patrol depends 

 upon the wholehearted cooperation of all ship traversing the area 

 and thanks are expressed to those whose participation made this 

 international service possible. 



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