5. Assume that the FM receiver represented in figure 4-5 is to be equipped with
automatic frequency control. If block V is a phase discriminator, what is in the
block labeled AFC and where is it connected?
a. Reactance modulator, connected between points A and D
b. Discriminator, connected between points A and B
c. Tertiary coil, connected between points B and C
d. Rectifier, connected between points C and D
6. The FM receiver shown in figure 152 of TM 11-668 incorporates a number of
circuits that are typical of FM superheterodynes, including
a. an AFC circuit.
b. a squelch circuit.
c. a de-emphasis network.
d. a double-conversion IF.
7. Compared with other types of multimeters, the major advantage of the vacuum-
tube voltmeter in aligning an FM receiver is that it
a. provides a greater range of available voltage scales.
b. can be used to measure both positive and negative voltages.
c. has greater power-handling capabilities for high-voltage measurements.
d. permits more accurate measurements because it consumes less power from the
circuit under test.
8. Although the performance of an FM receiver may be improved by a rough
alignment, service equipment is required to achieve optimum performance.
The
equipment used to accomplish accurate visual alignment consists of a
b. FM signal generator and an oscilloscope.
c. synchronizer and an oscilloscope.
d. signal generator and a loudspeaker.
9. When testing the receiver shown in figure 153 of TM 11-668, a signal
generator is connected at the grid of V9 and a VTVM is connected across R20 and
R21.
Since the receiver must handle a deviation of 40 kHz, three different
unmodulated test signals of equal amplitude are injected and the VTVM readings
noted as follows:
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