The transducer is Model LC-35, manufactured by Atlantic Research Corporation, with the 

 housing manufactured by the David Taylor Model Basin. The transducer output is approxi- 

 mately 90 db (rel. 1 dyne/cm^) which, dependent upon sea conditions, gives reliable range 

 readings to 2000 yd. 



LABORATORY SHIP COMPONENT DESCRIPTION 



The following ARMS equipment is employed by the laboratory ship, 



TIME STANDARD (Ship) 



The laboratory time standard is identical to the one used on board the submarine. 



FREQUENCY DIVIDER 



The frequency divider provides accurately timed pulses for the operation of the range 

 counter. As shown in Figure 6, the FS-llOOT 100-kc output signal is divided successively 

 by five identical decade dividers; each decade divider consists of four flip-flops and 

 associated gating circuits. The 1-cps output of the last decade is further divided to yield 

 1/2-cps and 1/4-cps repetition rate pulses. Any of the latter pulses plus the 1-sec pulse 

 may be selected, as required, to provide a 1-, 2-, or 4-sec range readout rate. The 10-kc 

 output of the first decade is also divided by 6 to obtain the 1.67-kc range-counting frequency. 



A flip-flop and two AND gates are used to generate two 1-kc pulses of 20-msec 

 duration; one with a 1-sec repetition rate and one with a 4-sec repetition rate. These two 

 pulses drive lights for visual indication of their occurrence and show the time of transmission 

 of the acoustic pulse. 



RANGE COUNTER 



The range counter measures the time of travel of the acoustic pulse from the submarine 

 to the receiving hydrophones and reads out the corresponding range. 



To read out this range in yards, pulses are counted at a 1.67-kc rate in a binary coded 

 decimal register. Each decimal digit of the register is shown in the block diagram of Figure 

 7 and is marked in units, tens, etc. The count proceeds from zero to 1000, 3000, or 6000, 

 depending on the position of the Switch SW^. The switch sections SW^-B and SW^-C and the 

 Gates G-1 and G-2 sense the desired highest number to be counted. When the desired number 

 is reached. Flip-flop Q-2 is reset; this flip-flop resets the thousands digit to zero. Also, 

 when Q-2 is reset, it stops the count through the action of G-3, which acts as an AND gate. 



At the moment an acoustic pulse leaves the submarine, a synchronized pulse is gen- 

 erated by the laboratory frequency divider, which triggers Q-1 to the zero state. Ten msec 

 later it is triggered back to the one state, which causes a pulse to trigger Q-2 to the one state. 



