mirror of
https://github.com/idanoo/nzart-exam-generator.git
synced 2024-12-04 22:26:58 +00:00
320 lines
6.6 KiB
Plaintext
320 lines
6.6 KiB
Plaintext
% FILENAME = N18.TXT
|
|
% Transmitter Block Diagrams
|
|
% Release version 3, October 2001
|
|
|
|
%Question 1
|
|
#18.1 In the transmitter block diagram shown, the "oscillator":
|
|
<img src = "ssbtx.gif" align = center width = 483 height = 145>
|
|
<totallines = 15 >
|
|
|
|
is variable in frequency
|
|
|
|
generates an audio frequency tone during tests
|
|
|
|
uses a crystal for good frequency stability
|
|
|
|
may have a calibrated dial
|
|
|
|
% ans 3
|
|
|
|
|
|
%Question 2
|
|
#18.2 In the transmitter block diagram shown, the "balanced modulator":
|
|
<img src = "ssbtx.gif" align = center width = 483 height = 145>
|
|
<totallines = 15 >
|
|
|
|
balances the high and low frequencies in the audio signal
|
|
|
|
performs double sideband suppressed carrier modulation
|
|
|
|
acts as a tone control
|
|
|
|
balances the standing wave ratio
|
|
|
|
% ans 2
|
|
|
|
|
|
%Question 3
|
|
#18.3 In the transmitter block diagram shown, the "filter":
|
|
<img src = "ssbtx.gif" align = center width = 483 height = 145>
|
|
<totallines = 15 >
|
|
|
|
removes mains hum from the audio signal
|
|
|
|
suppresses unwanted harmonics of the RF signal
|
|
|
|
removes one sideband from the modulated signal
|
|
|
|
removes the carrier component from the modulated signal
|
|
|
|
% ans 3
|
|
|
|
|
|
%Question 4
|
|
#18.4 In the transmitter block diagram shown, the "mixer":
|
|
<img src = "ssbtx.gif" align = center width = 483 height = 145>
|
|
<totallines = 15 >
|
|
|
|
adds the correct proportion of carrier to the SSB signal
|
|
|
|
mixes the audio and RF signals in the correct proportions
|
|
|
|
translates the SSB signal to the required frequency
|
|
|
|
mixes the two sidebands in the correct proportions
|
|
|
|
% ans 3
|
|
|
|
|
|
%Question 5
|
|
#18.5 In the transmitter block diagram shown, the "linear amplifier":
|
|
<img src = "ssbtx.gif" align = center width = 483 height = 145>
|
|
<totallines = 15 >
|
|
|
|
has all components arranged in-line
|
|
|
|
amplifies the modulated signal with no distortion
|
|
|
|
aligns the two sidebands correctly
|
|
|
|
removes any unwanted amplitude modulation from the signal
|
|
|
|
% ans 2
|
|
|
|
%Question 6
|
|
#18.6 In the transmitter block diagram shown, the "VFO" is:
|
|
<img src = "ssbtx.gif" align = center width = 483 height = 145>
|
|
<totallines = 15 >
|
|
|
|
a voice frequency oscillator
|
|
|
|
a varactor fixed oscillator
|
|
|
|
a virtual faze oscillator
|
|
|
|
a variable frequency oscillator
|
|
|
|
% ans 4
|
|
|
|
|
|
%Question 7
|
|
#18.7 In the transmitter block diagram shown, the "master oscillator" produces:
|
|
<img src = "cwtx.gif" align = center width = 404 height = 163>
|
|
<totallines = 13>
|
|
|
|
a steady signal at the required carrier frequency
|
|
|
|
a pulsating signal at the required carrier frequency
|
|
|
|
a 800 Hz signal to modulate the carrier
|
|
|
|
a modulated CW signal
|
|
|
|
% ans 1
|
|
|
|
|
|
%Question 8
|
|
#18.8 In the transmitter block diagram shown, the "driver buffer":
|
|
<img src = "cwtx.gif" align = center width = 404 height = 163>
|
|
<totallines = 13>
|
|
|
|
filters any sharp edges from the input signal
|
|
|
|
drives the power amplifier into saturation
|
|
|
|
provides isolation between the oscillator and power amplifier
|
|
|
|
changes the frequency of the master oscillator signal
|
|
|
|
% ans 3
|
|
|
|
|
|
%Question 9
|
|
#18.9 In the transmitter block diagram shown, the "Morse key":
|
|
<img src = "cwtx.gif" align = center width = 404 height = 163>
|
|
<totallines = 13>
|
|
|
|
turns the DC power to the transmitter on and off
|
|
|
|
allows the oscillator signal to pass only when the key is depressed
|
|
|
|
changes the frequency of the transmitted signal when the key is
|
|
depressed
|
|
|
|
adds an 800 Hz audio tone to the signal when the key is depressed
|
|
|
|
% ans 2
|
|
|
|
|
|
|
|
%Question 10
|
|
#18.10 In the transmitter block diagram shown, the "power amplifier":
|
|
<img src = "cwtx.gif" align = center width = 404 height = 163>
|
|
<totallines = 13 >
|
|
|
|
need not have linear characteristics
|
|
|
|
amplifies the bandwidth of its input signal
|
|
|
|
must be adjusted during key-up conditions
|
|
|
|
should be water-cooled
|
|
|
|
% ans 1
|
|
|
|
|
|
%Question 11
|
|
#18.11 In the transmitter block diagram shown, the "speech amplifier":
|
|
<img src = "fmtx.gif" align = center width = 600 height = 143>
|
|
<totallines = 16 >
|
|
|
|
amplifies the audio signal from the microphone
|
|
|
|
is a spectral equalization entropy changer
|
|
|
|
amplifies only speech, while discriminating against background noises
|
|
|
|
shifts the frequency spectrum of the audio signal into the RF region
|
|
|
|
% ans 1
|
|
|
|
|
|
%Question 12
|
|
#18.12 In the transmitter block diagram shown, the "modulator":
|
|
<img src = "fmtx.gif" align = center width = 600 height = 143>
|
|
<totallines = 16>
|
|
|
|
is an amplitude modulator with feedback
|
|
|
|
is an SSB modulator with feedback
|
|
|
|
causes the speech waveform to gate the oscillator on and off
|
|
|
|
causes the speech waveform to shift the frequency of the oscillator
|
|
|
|
% ans 4
|
|
|
|
|
|
%Question 13
|
|
#18.13 In the transmitter block diagram shown, the "oscillator" is:
|
|
<img src = "fmtx.gif" align = center width = 600 height = 143>
|
|
<totallines = 16 >
|
|
|
|
an audio frequency oscillator
|
|
|
|
a variable frequency RF oscillator
|
|
|
|
a beat frequency oscillator
|
|
|
|
a variable frequency audio oscillator
|
|
|
|
% ans 2
|
|
|
|
|
|
%Question 14
|
|
#18.14 In the transmitter block diagram shown, the "frequency multiplier":
|
|
<img src = "fmtx.gif" align = center width = 600 height = 143>
|
|
<totallines = 16 >
|
|
|
|
translates the frequency of the modulated signal into the RF spectrum
|
|
|
|
changes the frequency of the speech signal
|
|
|
|
produces a harmonic of the oscillator signal
|
|
|
|
multiplies the oscillator signal by the speech signal
|
|
|
|
% ans 3
|
|
|
|
|
|
|
|
|
|
|
|
%Question 15
|
|
#18.15 In the transmitter block diagram shown, the "power amplifier":
|
|
<img src = "fmtx.gif" align = center width = 600 height = 143>
|
|
<totallines = 16 >
|
|
|
|
increases the voltage of the mains to drive the antenna
|
|
|
|
amplifies the audio frequency component of the signal
|
|
|
|
amplifies the selected sideband to a suitable level
|
|
|
|
amplifies the RF signal to a suitable level
|
|
|
|
% ans 4
|
|
|
|
%Question 16
|
|
#18.16 The signal from an amplitude modulated transmitter consists of:
|
|
|
|
a carrier and two sidebands
|
|
|
|
a carrier and one sideband
|
|
|
|
no carrier and two sidebands
|
|
|
|
no carrier and one sideband
|
|
|
|
% ans 1
|
|
|
|
%Question 17
|
|
#18.17 The signal from a frequency modulated transmitter has:
|
|
|
|
an amplitude which varies with the modulating waveform
|
|
|
|
a frequency which varies with the modulating waveform
|
|
|
|
a single sideband which follows the modulating waveform
|
|
|
|
no sideband structure
|
|
|
|
% ans 2
|
|
|
|
%Question 18
|
|
#18.18 The signal from a balanced modulator consists of:
|
|
|
|
a carrier and two sidebands
|
|
|
|
a carrier and one sideband
|
|
|
|
no carrier and two sidebands
|
|
|
|
no carrier and one sideband
|
|
|
|
% ans 3
|
|
|
|
%Question 19
|
|
#18.19 The signal from a CW transmitter consists of:
|
|
|
|
a continuous, unmodulated RF waveform
|
|
|
|
a continuous RF waveform modulated with an 800 Hz Morse signal
|
|
|
|
an RF waveform which is keyed on and off to form Morse characters
|
|
|
|
a continuous RF waveform which changes frequency in synchronism with
|
|
an applied Morse signal
|
|
|
|
% ans 3
|
|
|
|
%Question 20
|
|
#18.20 The following signal can be amplified using a non-linear
|
|
amplifier:
|
|
|
|
SSB
|
|
|
|
FM
|
|
|
|
AM
|
|
|
|
DSBSC
|
|
|
|
% ans 2
|
|
|
|
|
|
|
|
|
|
|
|
|