CHAPTER 3 FUNDAMENTAL SYSTEMS EQUIPMENT

3-1 CHAPTER 3 FUNDAMENTAL SYSTEMS EQUIPMENT LEARNING OBJECTIVES Upon completion of this chapter you will be able to: 1. State the function of a radio communications handset, a radio set control, and a transfer switchboard. 2. Describe the functions and interrelationships of a radio transmitter. 3. Describe the functions of receive and transmit multicouplers. 4. Describe the differences between the codes used for manual telegraphy and teletypewriter transmissions. 5. Describe the two basic modes of teletypewriter operation. 6. Describe the two types of teletypewriter dc circuits. 7. State the two types of radio teletypewriter shift systems and describe their basic differences. 8. Describe the functions and interrelationships of radio-frequency-carrier shift send and receive systems. 9. Describe the signal flow in an audio-frequency-tone shift system. 10. State the function of the tone terminal set in an audio-frequency-tone shift system. 11. Describe the basic multiplexing process. 12. Describe the three operations performed by a facsimile system. 13. Describe the functions and interrelationships of facsimile equipment. 14. Describe the countermeasures that can be used to eliminate compromising emanations. EQUIPMENT PURPOSES A communications system is a collection of equipment used together to do a specific job. You may see this equipment used to send or receive voice communications, or both, or to send, receive, or send and receive teletypewriter information. Figure 3-1 is a basic block diagram of a voice system. You can see how this equipment is interconnected to form a basic communications system. We are going to look at several of the equipment blocks in detail.