AP 3302 Pt. 3
Section 1
CHAPTER 2
Basic Requirements Of A Pulse-Modulated Radar System
This
may be done by the transmit-receive (T-R) switch, the action of which is illustrated
in Fig 7. Although the T-R switch is represented here by the conventional symbol
for a switch, in practice it is an electronic device which operates automatically.
Normal mechanical switches or relays cannot be used because of the very high
rate of switching.
Output to indicator. We have seen that information on the angular position of the aerial is conveyed to a p.p.i. for indication of bearing in azimuth, and information on the angle of tilt is conveyed to a range-height indicator for indication of bearing in elevation. This is done by one of the remote position indication systems discussed in Part 1 of these notes, i.e. Desynn, M-type or synchro systems. A typical arrangement is illustrated in Fig 8.
Receiver
The receiver amplifies the reflected pulses picked up by the aerial. After amplification the pulses are demodulated and the resulting d.c. pulses are applied to the indicator c.r.t. for
