8
1-66. Which of the following inputs is/are
applied to the grid of a control-grid
modulator?
1. Rf
2. Af
3. Dc bias
4. Each of the above
1-67. Excessive modulating signal levels have
which, if any, of the following effects on
a control-grid modulator?
1. They increase output. amplitude
2. They decrease output amplitude
3. They create distortion
4. None
1-68. Compared to a plate modulator, the
control-grid modulator has which of the
following advantages?
1. It is more efficient
2. It has less distortion
3. It requires less power from the
modulator
4. It requires less power from the
amplifier
1-69. The control-grid modulator is similar to
which of the following modulator
circuits?
1. Plate
2. Cathode
3. Base-injection
4. Emitter-injection
Figure 1A.—Modulator circuit.
IN ANSWERING QUESTIONS 1-70
THROUGH 1-72, REFER TO FIGURE 1A.
1-70. What components in the circuit establish
the bias for Q1?
1. R1 and R2
2. R2 and R3
3. R1 and R3
1-71. The rf voltage in the circuit is applied at
(a) what points and the af voltage is
applied at (b) what points?
1. (a) A and B
(b) C and D
2. (a) C and D
(b) A and B
3. (a) C and D
(b) E and F
4. (a) E and F
(b) C and D
1-72. What components develop the rf
modulation envelope?
1. C1 and R1
2. C2 and R1
3. C3 and R3
4. C4 and L1
