1-3.
TRANSISTORIZED RF AMPLIFIER
The RF amplifier stages illustrated in figure 1-2 are representative of those in
a typical two-stage circuit used in an FM receiver.
The two stages contain PNP
transistors connected in the common-base configuration.
Coupling between the
antenna and the first RF amplifier, and between the two amplifiers, is accomplished
by circuits that are variations of the one shown in E of figure 1-1. Operating the
two RF amplifiers in the common-base configuration eliminates the necessity for
neutralization and minimizes changes in RF gain that may be caused by variations in
the supply voltage. The three tunable tank circuits provide a means of obtaining
the desired RF selectivity.
Figure 1-2.
Transistorized RF amplifier.
LESSON EXERCISES
In each of the following exercises, select the ONE answer that BEST completes
the statement or answers the question.
Indicate your solution by circling the
letter opposite the correct answers in the subcourse booklet.
1. The double superheterodyne receiver is often used in very high frequency
military communications.
Compared with the standard superheterodyne, the double
superheterodyne has the advantage of
a. greater frequency deviation.
b. fewer stages for portable equipment.
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