12. A wavetrap like that shown in B of figure 198, TM 11-665, is to be used to
eliminate image interference when the receiver is tuned to 15,252 kHz. The IF is
462 kHz and the oscillator is tuned higher than the incoming signals.
frequency to which the wavetrap should be tuned is
a. 14,328 kHz.
c. 15,714 kHz.
b. 14,790 kHz.
d. 16,176 kHz.
13. The RF stage shown in figure 199 of TM 11-665 has both automatic gain control
and manual gain control.
Both automatic and manual control circuits control the
output of the RF stage by
a. varying the bias voltage.
b. varying the cutoff point of the amplifier.
c. counteracting completely the effects of fading.
d. permitting a more favorable image rejection ratio.
14. Double-conversion receivers are often used in very high frequency (VHF) radio
systems. The primary purpose of double conversion in VHF receivers is to provide
a. higher gain.
b. better selectivity.
c. reduced image response.
d. higher signal-to-noise ratio.
a. low-power PNP.
c. high-power PNP.
b. low-power NPN.
d. high-power NPN.
is needed because the
a. strong signals easily overload the RF amplifier.
c. bias voltage prevents the RF amplifier from amplifying weak signals.