Chapter 6— PRINCIPLES OF SONAR 



and lower horizontal lines. Next, select the 

 other position on the switch and make the same 

 adjustments for the other channel. The equip- 

 ment is now ready to record on both channels. 



To start the recording process, an unlabeled 

 button to the right of the record level indicator 

 is held to the left, and the tape recorder control 

 (record section) is moved up to the No. 1 

 position. A light (indicator No. 1) glows as the 

 equipment begins to record. 



The unlabeled button is called the record 

 safety interlock switch. Its function is to prevent 

 accidental or inadvertent recording. To record, 

 you must place the record switch in the No. 1 

 position, and simultaneously turn the record 

 safety interlock switch to the left. 



To stop recording, set the record switch to 

 the neutral (middle) position. To start recording 

 again, move the safety interlock once more to 

 the left as the record switch is returned to the 

 No. 1 position. 



The other position of the record switch is 

 labeled AUX (for auxiliary). This position is 

 provided for use if an auxiliary recorder- 

 reprod' cer is added to the system. 



Recording ., :"i Remote Location 



A device that allows some control of the 

 assembly from remote locations is included 

 with the tape recorder. A single operating con- 

 trol and two indicating lamps (labeled STANDBY 

 and RECORD) are on the remote control imit. 

 The single operating control is a two-position 

 toggle switch that parallels the record switch 

 on the amplifier section. Preliminary adjust- 

 ments, such as tape threading and level control, 

 must be set before using the remote control 

 unit. The standby light indicates that power has 

 been applied and that tape is threaded. It does 

 not signify selection of the proper speed nor 

 adjustment of the level controls. It does not 

 light when no power is applied, when the tape 

 is threaded improperly, nor when the equipment 

 is used to reproduce a previously recorded tape. 



The positions of the toggle switch are STAND- 

 BY and RECORD. The standby position corre- 

 sponds to the neutral position of the record 

 switch on the recorder proper. The record 

 position takes precedence at both locations, 

 meaning that if RECORD is selected on the re- 

 mote control unit, the equipment will record 

 even though the record switch on the equipment 

 proper is in neutral. If RECORD is selected 

 on the instrument proper, but STANDBY is set 

 on the remote control unit, the equipment will 



record again. Thus, a tape being reproduced on 

 the recorder proper can be ruined (by the 

 automatic erasure process during recording) if 

 the switch at the remote control unit is set to 

 the record position during playback. Consequently, 

 the switch on the remote control unit must never 

 be moved from the standby position unless the 

 standby light is glowing. 



When the machine is recording, the RECORD 

 light on the remote control unit glows. When 

 approximately 5 minutes of recording time re- 

 mains on the tape, the RECORD lamp flashes 

 to warn that the end of the reel is approaching. 

 If the recorder cuts out (this feature is auto- 

 matic when the tape reel is exhausted), the 

 RECORD light goes out. When the tape recorder 

 returns to a standby condition, the STANDBY 

 light glows again. 



Reproducing 



To play a recording, thread the tape, turn 

 on the power switch, allow for warmup, and 

 choose the tape speed. 



Next, place the REPRODUCE switch in the 

 No. 1 position (it has the same positions as the 

 RECORD switch). This setting actuates tape 

 motion, and both channels are reproduced simul- 

 taneously. 



Finally, adjust the reproduce level controls 

 for both channels to the desired output of each 

 of the headphones (if used) or the loudspeaker. 



To stop the playback, simply return the 

 reproduce switch to the neutral (middle) position. 

 This stoppage may occur at will throughout the 

 run of the reel. The equipment returns to the 

 standby condition whenever the neutral position 

 is selected. As in the recording mode, the tape 

 motion stops automatically when the end of the 

 reel is reached. 



Remember that the switch on the remote 

 control unit must not be set to record during 

 the reproduction mode of operation. Otherwise, 

 the recording will be ruined. 



OTHER USES 



The tape recorder allows simultaneous re- 

 cording and reproducing of sounds. By this 

 means, you can monitor what is being recorded 

 as it is recorded. Steps to set the equipment 

 to this mode of operation are included in the 

 equipment instruction book. Technical Manual . 

 Recorder-Reproducer Set. Sound. AN/UNQ-7, 

 NavShips 365-2471. 



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