nzart-exam-generator/files/N17.TXT

% FILENAME = N17.TXT
% Receiver Operation 
% Release version 3, October 2001
% Q 23 modified 6 Mar 2012

%QUESTION: 1
#17.1 The frequency stability of a receiver is its ability to:

stay tuned to the desired signal

track the incoming signal as it drifts 

provide a frequency standard 

provide a digital readout 

% ans 1 

%QUESTION: 2
#17.2 The sensitivity of a receiver specifies: 

the bandwidth of the RF preamplifier 

the stability of the oscillator 

its ability to receive weak signals 

its ability to reject strong signals 

% ans 3 

%QUESTION: 3
#17.3 Of two receivers, the one capable of receiving the weakest signal will have: 

an RF gain control 

the least internally-generated noise 

the loudest audio output 

the greatest tuning range 

% ans 2 

%QUESTION: 4 
#17.4 The figure in a receiver's specifications which indicates its sensitivity is the: 

bandwidth of the IF in kilohertz 

audio output in watts 

signal plus noise to noise ratio 

number of RF amplifiers 

% ans 3 

%QUESTION: 5 
#17.5 If two receivers are compared, the more sensitive receiver will produce: 

more than one signal 

less signal and more noise

more signal and less noise 

a steady oscillator drift 

% ans 3 

%QUESTION: 6 
#17.6 The ability of a receiver to separate signals close in frequency is called its: 

noise figure 

sensitivity 

bandwidth 

selectivity 

% ans 4 

%QUESTION: 7 
#17.7 A receiver with high selectivity has a: 

wide bandwidth 

wide tuning range 

narrow bandwidth 

narrow tuning range 

% ans 3 

%QUESTION: 8 
#17.8 The BFO in a superhet receiver operates on a frequency nearest to that of its: 

RF amplifier 

audio amplifier 

local oscillator 

IF amplifier 

% ans 4 

%QUESTION: 9 
#17.9 To receive Morse code signals, a BFO is employed in a superhet receiver to: 

produce IF signals 

beat with the local oscillator signal to produce sidebands 

produce an audio tone to beat with the IF signal 

beat with the IF signal to produce an audio tone 

% ans 4 

%QUESTION: 10 
#17.10 The following transmission mode is usually demodulated by a product detector: 

pulse modulation 

double sideband full carrier modulation 

frequency modulation 

single sideband suppressed carrier modulation 

% ans 4 

%QUESTION: 11 
#17.11 A superhet receiver for SSB reception has an insertion oscillator to: 

replace the suppressed carrier for detection 

phase out the unwanted sideband signal 

reduce the passband of the IF stages 

beat with the received carrier to produce the other sideband 

% ans 1 

%QUESTION: 12 
#17.12 A stage in a receiver with input and output circuits tuned to the received frequency is the: 

RF amplifier 

local oscillator 

audio frequency amplifier 

detector 

% ans 1 

%QUESTION: 13 
#17.13 An RF amplifier ahead of the mixer stage in a superhet receiver: 

enables the receiver to tune a greater frequency range 

means no BFO stage is needed 

makes it possible to receive SSB signals 

increases the sensitivity of the receiver 

% ans 4 

%QUESTION: 14 
#17.14 A communication receiver may have several IF filters of different bandwidths. The operator selects one to:

improve the S-meter readings 

improve the receiver sensitivity 

improve the reception of different types of signal 

increase the noise received 

% ans 3 

%QUESTION: 15 
#17.15 The stage in a superhet receiver with a tuneable input and fixed tuned output is the: 

RF amplifier 

mixer stage 

IF amplifier 

local oscillator 

% ans 2 

%QUESTION: 16 
#17.16 The mixer stage of a superhet receiver: 

produces spurious signals 

produces an intermediate frequency signal 

acts as a buffer stage 

demodulates SSB signals 

% ans 2 

%QUESTION: 17 
#17.17 A 7 MHz signal and a 16 MHz oscillator are applied to a mixer stage. The output will contain the input frequencies and: 

8 and 9 MHz 

7 and 9 MHz 

9 and 23 MHz 

3.5 and 9 MHz 

% ans 3 

%QUESTION: 18 
#17.18 Selectivity in a superhet receiver is achieved primarily in the: 

RF amplifier 

Mixer 

IF amplifier 

Audio stage 

% ans 3 

%QUESTION: 19 
#17.19 The abbreviation AGC means: 

attenuating gain capacitor 

automatic gain control 

anode-grid capacitor 

amplified grid conductance 

% ans 2 

%QUESTION: 20 
#17.20 The AGC circuit in a receiver usually controls the: 

audio stage 

mixer stage 

power supply 

RF and IF stages 

% ans 4 

%QUESTION: 21 
#17.21 The tuning control of a superhet receiver changes the tuned frequency of the: 

audio amplifier 

IF amplifier 

local oscillator 

post-detector amplifier 

% ans 3 

%QUESTION: 22 
#17.22 A superhet receiver, with an IF at 500 kHz, is receiving a 14 MHz signal. The local oscillator frequency is: 

14.5 MHz 

19 MHz 

500 kHz 

28 MHz 

% ans 1 

%QUESTION: 23 
#17.23 An audio amplifier is necessary in an AM receiver because: 

signals leaving the detector are weak 

the carrier frequency must be replaced 

the signal requires demodulation 

RF signals are not heard by the human ear 

% ans 1 

%QUESTION: 24 
#17.24 The audio output transformer in a receiver is required to: 

step up the audio gain 

protect the loudspeaker from high currents 

improve the audio tone 

match the output impedance of the audio amplifier to the speaker 

% ans 4 

%QUESTION: 25 
#17.25 If the carrier insertion oscillator is counted, then a single conversion superhet receiver has: 

one oscillator 

two oscillators 

three oscillators 

four oscillators 

% ans 2 

%QUESTION: 26 
#17.26 A superhet receiver, with a 500 kHz IF, is receiving a signal at 21.0 MHz. A strong unwanted signal at 22 MHz is interfering. The cause is: 

insufficient IF selectivity 

the 22 MHz signal is out-of-band 

22 MHz is the image frequency 

insufficient RF gain 

% ans 3 

%QUESTION: 27 
#17.27 A superhet receiver receives an incoming signal of 3540 kHz and the local oscillator produces a signal of 3995 kHz. The IF amplifier is tuned to: 

455 kHz 

3540 kHz 

3995 kHz 

7435 kHz 

% ans 1 

%QUESTION: 28 
#17.28 A double conversion receiver designed for SSB reception has a carrier insertion oscillator and: 

one IF stage and one local oscillator 

two IF stages and one local oscillator 

two IF stages and two local oscillators 

two IF stages and three local oscillators 

% ans 3           

%QUESTION: 29 
#17.29 An advantage of a double conversion receiver is that it: 

does not drift off frequency 

produces a louder audio signal 

has improved image rejection characteristics 

is a more sensitive receiver 

% ans 3 

%QUESTION: 30 
#17.30 A receiver squelch circuit: 

automatically keeps the audio output at maximum level

silences the receiver speaker during periods of no received signal 

provides a noisy operating environment 

is not suitable for pocket-size receivers 

% ans 2