INTRODUCTION TO SONAR 



The only way to learn code is by practice — con- 

 tinual practice. (Practice makes perfect.) The 

 value of practice cannot be overemphasized, as you 

 will learn when you test yourself, with the help 

 of your shipmates, to find out how much you have 

 learned through practicing by yourself. 



If you have carried out the recommendations 

 made up to this point, you are ready to receive 

 code transmitted to you on a hand key. The ship 

 or station to which yoa are attached has practice 

 hand keys you can use. 



Find a Radioman who will key code groups 

 to you to help you in your training. The sound 



produced by keying an oscillator resembles 

 the sound of code from the sonar trans- 

 mitter. 



After you learn the sound of each character 

 at a slow rate of speed, it is not difficult to 

 reduce the time between characters and thus to 

 copy at a much faster speed. But don't strive 

 for speed before accuracy. Be a competent 

 operator. Make every transmission and recep- 

 tion accurately. Accuracy is much easier if you 

 learn the fundamentals well. Some code practice 

 exercises that will help you are included for 

 your convenience. 



CODE PRACTICE 



138 



