3-23
Figure 3-22.—Basic radio-frequency-carrier shift system (rfcs).
In both the tone-modulated system and the carrier-frequency shift system, all tty signals pass through
the tty panel that controls the looping current in all the circuits. Looping current is the current supplied by
the tty battery. The tty panel integrates the tone-modulated and the carrier-frequency shift systems. It
provides every possible interconnection of available tty equipment. With this configuration maximum
operational flexibility is achieved with the least amount of circuitry and equipment.
Q19. What is the function of a keyer?
Q20. What is the function of a converter?
Q21. Basically describe an afts system.
Q22. Basically describe an rfcs system.
Rfcs Send System
Figure 3-23 shows an rfcs teletypewriter transmit communications system. You should refer to this
figure frequently while reading the functional descriptions of the equipment shown.
