ABSTRACT 



Thia report, to be used in conjunction with USL Report No„ 55 

 "Long Distance Sound Ranging Equipment (SOFAR) - Installation and 

 Operating Notes," provides complete instructions for maintenance 

 work and performance tests on the SOFAR equipment The initial 

 alignment, self noise measurements, gain and output calibration, 

 and servicing of the amplifiers are described; the adjustment and 

 operation of the automatic switching unit, graphic level and magnetic 

 tape recorders, chronometer and code switch, and shot arrival time 

 evaluator are explained in detail; and general maintenance instructions 

 are presented,, 



AUTHORIZATION 



U Sj, Navy Underwater Sound Laboratory Project D74> authorized 

 under BuShips Problem P-17.1„ 



