storage. Periodic inspections of the feed-through assemblies will 

 be necessary. Re-packing should be determined by condition of 

 assemblies. 



Fig. 10. Telemeter assembly showing transmitter, receiving hydro- 

 phone, power supply, pre- amplifier and RBA-6 receiver. 



TRIALS AND TESTS 



Two tests of the completed instrument were run: a test for 

 distance, and a test for depth. 



Distance and Directivity 



A shallow-water distance test was run in Government Cut at Miami 

 Beach, Fla. The receiver and receiving transducer were on shore at 

 a vantage point enabling a clear shot across the channel for approxi- 

 mately 1.2 miles. During the test, there was considerable noise from 

 the various power boats in the inmediate vicinity, and conditions were 

 by no means ideal. The telemeter transmitter was suspended from a 

 small motor launch to a depth of approximately 7 feet. Excellent 

 signals were received as far as 1 mile, and extremely strong signals 

 were received at 3,000 feet. Tone modulation was readable at all times. 



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