Chapter 8 — COMMUNICATIONS 



SPACE ADJUSTING BINDING 

 SCREW \ POST 



LOCK NUT 



LATERAL 

 BLOCK 



TRUNNION SCREW 



SPRING TENSION 

 SCREW 



LOCK NUT 



TRUNNION 

 SCREW 



LOCK NUT 



LATERAL BLOCK 



TENSION SPRING 



KEY BUTTON 

 CONTACTS 



76,8A 



Figure 8-1.— Hand key. 



"open" are terms for a short and a long gap. 

 As the student progresses, further gap adjust- 

 ment may be made to suit his sending speed. 

 Contacts that are too close have an effect simJlax 

 to weak spring tension. Contacts that are spaced 

 too far have the same effect as too much spring 

 tension. 



The final adjustment of the key is the side- 

 wise alignment of the contact points. This align- 

 ment is controlled by the tnumion screws at 

 either side of the key. If they are too tight, the 

 key lever binds. If they are too loose, the 

 contacts have sidewise play. Usually, when the 

 sidewlse alignment is correct, no further adjust- 

 ment is required. 



From the beginning you should learn the 

 correct way to grasp the key. The following 

 instructions, in the order listed, constitute the 

 proper procedure for becoming a proficient 

 operator: Do not hold the key tightly, but let 

 your fingers rest lightly on the key knob. Your 

 thumb rests against the side, your forefinger 

 rests on top of the key; your third finger is 

 bent and relaxed with the remaining two fingers. 



Speed and accuracy of transmission depend, 

 to a large extent, on acquiring the proper move- 

 ments of your wrist and hand while operating 

 the key. To close the key, your wrist moves 

 upward and your hand rocks downward toward 

 your fingertips. To open the key, these two 

 movements are reversed — your wrist comes 

 down and your hand rocks back. A dah should 

 be about three times as long as a dit. 



Conditions of the water have a bearing on 

 the speed at which you will be able to transmit. 

 At times you can transmit rapidly and your 

 signals will be clearly audible. Other times 

 you may have to go very slowly, otherwise your 

 dlts and dahs cannot be distinguished by the 

 receiving operator, 



UNDERWATER COMMUNICATIONS 



For many reasons it is necessary for a 

 ship and a submerged submarine to communicate 

 with each other. Of paramount importance is the 

 safety of the submarine and its crew. During 

 exercise periods the ship can advise the sub- 

 marine when it is safe to surface. Should an 

 emergency arise aboard the submarine, the ship 

 can be so informed. Exercises can be started 

 and stopped, or one in progress can be modified, 

 by using the underwater telephone. Attack accu- 

 racy can be signaled by the submarine to the 

 attacking ship. Sonar Technicians must be pro- 

 ficient in radiotelephone procedures because 

 those techniques are used for underwater voice 

 communication. When CW (radiotelegraph) is 

 used, you must be able to send and receive 

 Morse code without causing delay or misunder- 

 standing. 



The most widely used underwater telephone 

 Installation is the AN/UQC-1 (and modifications) 

 sonar set, commonly called Gertrude. Although 

 intended for use by sonar control personnel, 

 some installations provide remote voice opera- 

 tion from the bridge and from CIC. It operates 

 as a single sideband suppressed carrier trans- 

 ceiver, with a modulated frequency of 8 to 11 kc. 

 It has a microphone for voice transmission and 

 a hand key for sending CW signals. Mounted 

 on the front panel of the control unit (fig. 8-2) 

 are a speaker, microphone, and earphone jacks, 

 on-off and receiver-transmit switches, a tele- 

 graph key, and three neon glow lamps indicating 

 output, plate voltage, and filament voltage. 



When you wish to transmit by voice, set the 

 toggle switch to VOICE & CW RECEIVE, plug 

 in the microphone, and depress the microphone 

 button. For CW transmission, set the toggle 

 switch to CW TRANSMIT and use the hand key. 

 (CAUTION: Do not operate in the CW mode for 

 longer than 30 minutes at a time. Operation for 

 longer periods causes excessive heating of the 

 transducer.) 



The range of transmission varies with water 

 conditions, local noise level, and reverberation 

 effects. Under normal sonar conditions, however, 

 communication between ships should be possible 



141 



