Transcript G4A01 Which of the following is one use for a DSP in an amateur

G4 - AMATEUR RADIO PRACTICES
[5 Questions - 5 groups]
G4A
G4B
G4C
G4D
G4E
Two-tone Test; amplifier tuning and neutralization; DSP
Test and monitoring equipment
Interference with consumer electronics; grounding
Speech processors; S meters; common connectors
HF mobile radio installations; emergency and battery
powered operation
1
Amateur Radio Practices
This is the 2nd IF (intermediate frequency) stage of the
Icom IC-756ProIII receiver.
The 455kHz IF frequency is converted to 36kHz and
digitized through an analog to digital converter.
2
Amateur Radio Practices
Once the signal has been digitized, DSP notch
filter, adjustable bandpass filters and noise
reduction filters can be applied.
3
Amateur Radio Practices
The level of the resulting signal is sampled and used to
determine the gain of the first IF stage. This level
information is fed back through a digital to analog
converter to the automatic gain control circuit on the 1st IF
stage.
4
Amateur Radio Practices
Finally the signal is fed through the DSP detector, then
a digital to analog converter to convert the signal back
to analog audio and sent to the amplifier and speaker.
5
Amateur Radio Practices
G4A01 Which of the following is one use for
a DSP in an amateur station?
A.
B.
C.
D.
To
To
To
To
provide adequate grounding
remove noise from received signals
increase antenna gain
increase antenna bandwidth
6
Amateur Radio Practices
G4A01 Which of the following is one use for
a DSP in an amateur station?
A. To provide adequate grounding
B.
To remove noise from received signals
C. To increase antenna gain
D. To increase antenna bandwidth
7
Amateur Radio Practices
Oscilloscope
This is a current model Tektronix oscilloscope. It has four signal inputs along
the lower right edge and can display the waveforms from those inputs. There
are three main sections to the right of the screen; vertical, horizontal and
trigger. The horizontal and vertical controls adjust how the waveform appears
on the screen by adjusting the horizontal and vertical amplifiers. The trigger
controls allow the oscilloscope to synchronize to external events.
8
Amateur Radio Practices
Audio Distortion
Two tone audio tests are used on an oscilloscope to test proper
linearity. The pure tones fed in will give you a stable picture on
the scope if the amplifier is properly adjusted.
9
Amateur Radio Practices
Audio Distortion
The lower image shows a signal with some noise that it also
overdriven (overmodulated) and is clipping or flattopping. Any
two audio tones may be used, but they must be within the
transmitter audio passband, and should not be harmonically
related
10
Amateur Radio Practices
Audio Distortion
Speech Processors are used to keep input audio close to a
perfect level for 100% modulation. If they are not adjusted
properly, they can cause the distortion seen here. Overdriving
causes very distorted audio and no additional power output.
11
Amateur Radio Practices
G4A02 Which of the following instruments
may be used to measure the output of a
single-sideband transmitter when
performing a two-tone test of amplitude
linearity?
A.
B.
C.
D.
An audio distortion analyzer
An oscilloscope
A directional wattmeter
A high impedance audio voltmeter
12
Amateur Radio Practices
G4A02 Which of the following instruments
may be used to measure the output of a
single-sideband transmitter when
performing a two-tone test of amplitude
linearity?
A. An audio distortion analyzer
B.
An oscilloscope
C. A directional wattmeter
D. A high impedance audio voltmeter
13
Amateur Radio Practices
G4A03 Which of the following is needed for a
DSP IF filter?
A.
B.
C.
D.
An Analog to Digital Converter
Digital to Analog Converter
A Digital Processor Chip
All of the these answers are correct
14
Amateur Radio Practices
G4A03 Which of the following is needed for a
DSP IF filter?
A. An Analog to Digital Converter
B. Digital to Analog Converter
C. A Digital Processor Chip
D.
All of the these answers are correct
15
Amateur Radio Practices
G4A04 Which of the following is an
advantage of a receiver IF filter created with
a DSP as compared to an analog filter?
A. A wide range of filter bandwidths and shapes can be
created
B. Fewer digital components are required
C. Mixing products are greatly reduced
D. The DSP filter is much more effective at VHF frequencies
16
Amateur Radio Practices
G4A04 Which of the following is an
advantage of a receiver IF filter created with
a DSP as compared to an analog filter?
A.
A wide range of filter bandwidths and shapes
can be created
B. Fewer digital components are required
C. Mixing products are greatly reduced
D. The DSP filter is much more effective at VHF frequencies
17
Amateur Radio Practices
G4A05 How is DSP filtering accomplished?
A. By using direct signal phasing
B. By converting the signal from analog to digital and using
digital processing
C. By up-converting the signal to VHF
D. By converting the signal from digital to analog and taking
the difference of mixing products
18
Amateur Radio Practices
G4A05 How is DSP filtering accomplished?
B.
By converting the signal from analog to digital
and using digital processing
19
Amateur Radio Practices
Linear Amplifier ---- POWER !!!!
20
Amateur Radio Practices
This is a Tokyo Hy-Power 1.5kW linear amplifier using two 3-500Z tubes. The
meter on the left is plate current and the right is grid current. It is
necessary to neutralize the tubes in an amplifier to prevent internal (self)
oscillation caused by positive feedback.
The correct adjustment for the "Load" or "Coupling" control provides maximum
power output without exceeding maximum allowable plate current. The
plate current meter of a vacuum tube RF power amplifier will show a
pronounced “dip” indicating the correct adjustment of the plate tuning
control.
A negative signal is used to cancel the effects of positive feedback.
21
Amateur Radio Practices
G4A06 What reading on the plate current
meter of a vacuum tube RF power amplifier
indicates correct adjustment of the plate
tuning control?
A.
B.
C.
D.
A pronounced peak
A pronounced dip
No change will be observed
A slow, rhythmic oscillation
22
Amateur Radio Practices
G4A06 What reading on the plate current
meter of a vacuum tube RF power amplifier
indicates correct adjustment of the plate
tuning control?
A. A pronounced peak
B.
A pronounced dip
C. No change will be observed
D. A slow, rhythmic oscillation
23
Amateur Radio Practices
G4A07 What is the correct adjustment for
the "Load" or "Coupling" control of a vacuum
tube RF power amplifier?
A. Minimum SWR on the antenna
B. Minimum plate current without exceeding maximum
allowable grid current
C. Highest plate voltage while minimizing grid current
D. Maximum power output without exceeding maximum
allowable plate current
24
Amateur Radio Practices
G4A07 What is the correct adjustment for
the "Load" or "Coupling" control of a vacuum
tube RF power amplifier?
A. Minimum SWR on the antenna
B. Minimum plate current without exceeding maximum
allowable grid current
C. Highest plate voltage while minimizing grid current
D.
Maximum power output without exceeding
maximum allowable plate current
25
Amateur Radio Practices
G4A08 Which of the following techniques is
used to neutralize an RF amplifier?
A.
B.
C.
D.
Feed-forward compensation
Feed-forward cancellation
Negative feedback
Positive feedback
26
Amateur Radio Practices
G4A08 Which of the following techniques is
used to neutralize an RF amplifier?
A. Feed-forward compensation
B. Feed-forward cancellation
C.
Negative feedback
D. Positive feedback
27
Amateur Radio Practices
G4A09 What does a neutralizing circuit do in
an RF amplifier?
A.
B.
C.
D.
It
It
It
It
controls differential gain
cancels the effects of positive feedback
eliminates AC hum from the power supply
reduces incidental grid modulation
28
Amateur Radio Practices
G4A09 What does a neutralizing circuit do in
an RF amplifier?
A. It controls differential gain
B.
It cancels the effects of positive feedback
C. It eliminates AC hum from the power supply
D. It reduces incidental grid modulation
29
Amateur Radio Practices
G4A10 What is the reason for neutralizing
the final amplifier stage of a transmitter?
A.
B.
C.
D.
To
To
To
To
limit the modulation index
eliminate self oscillations
cut off the final amplifier during standby periods
keep the carrier on frequency
30
Amateur Radio Practices
G4A10 What is the reason for neutralizing
the final amplifier stage of a transmitter?
A. To limit the modulation index
B.
To eliminate self oscillations
C. To cut off the final amplifier during standby periods
D. To keep the carrier on frequency
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Amateur Radio Practices
G4A11 What type of transmitter
performance does a two-tone test analyze?
A.
B.
C.
D.
Linearity
Carrier and undesired sideband suppression
Percentage of frequency modulation
Percentage of carrier phase shift
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Amateur Radio Practices
G4A11 What type of transmitter
performance does a two-tone test analyze?
A.
Linearity
33
Amateur Radio Practices
G4A12 What type of signals are used to
conduct a two-tone test?
A. Two audio signals of the same frequency shifted 90degrees
B. Two non-harmonically related audio signals
C. Two swept frequency tones
D. Two audio frequency range square wave signals of equal
amplitude
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Amateur Radio Practices
G4A12 What type of signals are used to
conduct a two-tone test?
A. Two audio signals of the same frequency shifted 90degrees
B.
Two non-harmonically related audio signals
C. Two swept frequency tones
D. Two audio frequency range square wave signals of equal
amplitude
35
Amateur Radio Practices
G4A13 Which of the following performs
automatic notching of interfering carriers?
A.
B.
C.
D.
Band pass tuning
A DSP filter
Balanced mixing
A noise limiter
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Amateur Radio Practices
G4A13 Which of the following performs
automatic notching of interfering carriers?
B.
A DSP filter
37
Amateur Radio Practices
G4B01 What item of test equipment contains
horizontal and vertical channel amplifiers?
A.
B.
C.
D.
An ohmmeter
A signal generator
An ammeter
An oscilloscope
38
Amateur Radio Practices
G4B01 What item of test equipment contains
horizontal and vertical channel amplifiers?
D.
An oscilloscope
39
Amateur Radio Practices
G4B02 Which of the following is an
advantage of an oscilloscope versus a digital
voltmeter?
A.
B.
C.
D.
An oscilloscope uses less power
Complex impedances can be easily measured
Input impedance is much lower
Complex waveforms can be measured
40
Amateur Radio Practices
G4B02 Which of the following is an
advantage of an oscilloscope versus a digital
voltmeter?
D.
Complex waveforms can be measured
41
Amateur Radio Practices
G4B03 How would a signal tracer normally
be used?
A.
B.
C.
D.
To
To
To
To
identify the source of radio transmissions
make exact drawings of signal waveforms
show standing wave patterns on open-wire feed-lines
identify an inoperative stage in a receiver
42
Amateur Radio Practices
G4B03 How would a signal tracer normally
be used?
A. To identify the source of radio transmissions
B. To make exact drawings of signal waveforms
C. To show standing wave patterns on open-wire feed-lines
D.
To identify an inoperative stage in a receiver
43
Amateur Radio Practices
Noise Bridge
A noise bridge is a device for measuring or comparing
impedances on coaxial cables, antennas, components,
etc. With appropriate calibration, it allows for the
measurement of both scalar and vector (reactive)
impedances.
A noise bridge contains a wideband noise generator as
well as a bridge balancing circuit, and makes use of
the station receiver, tuned to the frequency of
measurement, as a detector. The bridge is balanced
by changing a bridge capacitor and resistor while
listening to the receiver for a noise null.
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Amateur Radio Practices
45
Amateur Radio Practices
G4B04 How is a noise bridge normally used?
A. It is connected at an antenna's feed point and reads the
antenna's noise figure
B. It is connected between a transmitter and an antenna and
tuned for minimum SWR
C. It is connected between a receiver and an antenna of
unknown impedance and is adjusted for minimum noise
D. It is connected between an antenna and ground and tuned
for minimum SWR
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Amateur Radio Practices
G4B04 How is a noise bridge normally used?
A. It is connected at an antenna's feed point and reads the
antenna's noise figure
B. It is connected between a transmitter and an antenna and
tuned for minimum SWR
C.
It is connected between a receiver and an
antenna of unknown impedance and is adjusted for
minimum noise
D. It is connected between an antenna and ground and tuned
for minimum SWR
47
Amateur Radio Practices
G4B05 Which of the following is the best
instrument to use to check the keying
waveform of a CW transmitter?
A.
B.
C.
D.
A
A
A
A
monitoring oscilloscope
field-strength meter
sidetone monitor
wavemeter
48
Amateur Radio Practices
G4B05 Which of the following is the best
instrument to use to check the keying
waveform of a CW transmitter?
A.
A monitoring oscilloscope
49
Amateur Radio Practices
G4B06 What signal source is connected to
the vertical input of a monitoring
oscilloscope when checking the quality of a
transmitted signal?
A.
B.
C.
D.
The
The
The
The
local oscillator of the transmitter
audio input of the transmitter
transmitter balanced mixer output
attenuated RF output of the transmitter
50
Amateur Radio Practices
G4B06 What signal source is connected to
the vertical input of a monitoring
oscilloscope when checking the quality of a
transmitted signal?
A. The local oscillator of the transmitter
B. The audio input of the transmitter
C. The transmitter balanced mixer output
D.
The attenuated RF output of the transmitter
51
Amateur Radio Practices
G4B07 What is an advantage of a digital
voltmeter as compared to an analog
voltmeter?
A.
B.
C.
D.
Better for measuring computer circuits
Better for RF measurements
Significantly better precision for most uses
Faster response
52
Amateur Radio Practices
G4B07 What is an advantage of a digital
voltmeter as compared to an analog
voltmeter?
A. Better for measuring computer circuits
B. Better for RF measurements
C.
Significantly better precision for most uses
D. Faster response
53
Amateur Radio Practices
Field Strength Meter
54
Amateur Radio Practices
G4B08 What instrument may be used to
monitor relative RF output when making
antenna and transmitter adjustments?
A.
B.
C.
D.
A field-strength meter
An antenna noise bridge
A multimeter
A Q meter
55
Amateur Radio Practices
G4B08 What instrument may be used to
monitor relative RF output when making
antenna and transmitter adjustments?
A.
A field-strength meter
B. An antenna noise bridge
C. A multimeter
D. A Q meter
56
Amateur Radio Practices
Decibels
The Decibel scale is logarithmic. 3dB represents a 2fold increase in power, 6dB is 4 fold, 10dB is 10-fold,
20dB is 100-fold. The S-Unit scale on a receiver meter
is not an absolute scale and can vary from radio to
radio. Although these meters are not calibrated, they
can be useful for verifying antenna performance. One
“S-Unit” represents a 4-fold change in power or 6dB.
57
Amateur Radio Practices
Decibel Multipliers
28
26
24
22
20
Multiplier
18
16
14
12
10
8
6
4
2
0
0
1
2
3
4
5
6
7
8
9
10
11 12
13
14
Decibel (dB)
58
Amateur Radio Practices
G4B09 How much must the power output of
a transmitter be raised to change the "S"
meter reading on a distant receiver from S8
to S9?
A.
B.
C.
D.
Approximately 2
Approximately 3
Approximately 4
Approximately 5
times
times
times
times
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Amateur Radio Practices
G4B09 How much must the power output of
a transmitter be raised to change the "S"
meter reading on a distant receiver from S8
to S9?
A. Approximately 2 times
B. Approximately 3 times
C.
Approximately 4 times
D. Approximately 5 times
60
Amateur Radio Practices
G4B10 Which of the following can be
determined with a field strength meter?
A. The radiation resistance of an antenna
B. The radiation pattern of an antenna
C. The presence and amount of phase distortion of a
transmitter
D. The presence and amount of amplitude distortion of a
transmitter
61
Amateur Radio Practices
G4B10 Which of the following can be
determined with a field strength meter?
A. The radiation resistance of an antenna
B.
The radiation pattern of an antenna
C. The presence and amount of phase distortion of a
transmitter
D. The presence and amount of amplitude distortion of a
transmitter
62
Amateur Radio Practices
G4B11 Which of the following might be a use
for a field strength meter?
A. Close-in radio direction-finding
B. A modulation monitor for a frequency or phase modulation
transmitter
C. An overmodulation indicator for a SSB transmitter
D. A keying indicator for a RTTY or packet transmitter
63
Amateur Radio Practices
G4B11 Which of the following might be a use
for a field strength meter?
A.
Close-in radio direction-finding
B. A modulation monitor for a frequency or phase modulation
transmitter
C. An overmodulation indicator for a SSB transmitter
D. A keying indicator for a RTTY or packet transmitter
64
Amateur Radio Practices
G4B12 What is one way a noise bridge might
be used?
A.
B.
C.
D.
Determining an antenna's gain in dBi
Pre-tuning an antenna tuner
Pre-tuning a linear amplifier
Determining the line loss of the antenna system
65
Amateur Radio Practices
G4B12 What is one way a noise bridge might
be used?
A. Determining an antenna's gain in dBi
B.
Pre-tuning an antenna tuner
C. Pre-tuning a linear amplifier
D. Determining the line loss of the antenna system
66
Amateur Radio Practices
GRID DIP METER
Grid dip oscillator (GDO), also called grid dip meter, dip meter,
dipmeter, or just dipper, is a measuring instrument to measure
resonant frequency of radio frequency circuits. It measures the
amount of absorption of a high frequency inductively coupled
magnetic field by nearby objects. It is an oscillator whose
output energy changes in the vicinity of a resonant circuit
which is tuned to the frequency the oscillator generates;
somewhat similar to an acoustic tone becoming louder when
generated in the vicinity of a resonant cavity or a string tuned
to the same frequency. At the heart of the instrument is a
tunable LC circuit with a coil that serves as a loose inductive
coupling to the measured LC resonant circuit. Resonance is
indicated by a dip in the meter indicator on the device, usually
based on a microammeter.
67
Amateur Radio Practices
68
Amateur Radio Practices
G4B13 What is one measurement that can
be made with a dip meter?
A.
B.
C.
D.
The
The
The
The
resonant frequency of a circuit
tilt of the ionosphere
gain of an antenna
notch depth of a filter
69
Amateur Radio Practices
G4B13 What is one measurement that can
be made with a dip meter?
A.
The resonant frequency of a circuit
B. The tilt of the ionosphere
C. The gain of an antenna
D. The notch depth of a filter
70
Amateur Radio Practices
SWR Meter
71
Amateur Radio Practices
G4B14 Which of the following must be
connected to an antenna analyzer when it is
being used for SWR measurements?
A.
B.
C.
D.
Receiver
Transmitter
Antenna and feedline
All of these answers are correct
72
Amateur Radio Practices
G4B14 Which of the following must be
connected to an antenna analyzer when it is
being used for SWR measurements?
A. Receiver
B. Transmitter
C.
Antenna and feedline
D. All of these answers are correct
73
Amateur Radio Practices
G4B15 Which of the following can be
measured with a directional wattmeter?
A.
B.
C.
D.
Standing Wave Ratio
Antenna front-to-back ratio
RF interference
Radio wave propagation
74
Amateur Radio Practices
G4B15 Which of the following can be
measured with a directional wattmeter?
A.
Standing Wave Ratio
B. Antenna front-to-back ratio
C. RF interference
D. Radio wave propagation
75
Amateur Radio Practices
G4B16 Why is high input impedance
desirable for a voltmeter?
A.
B.
C.
D.
It
It
It
It
improves the frequency response
decreases battery consumption in the meter
improves the resolution of the readings
decreases the loading on circuits being measured
76
Amateur Radio Practices
G4B16 Why is high input impedance
desirable for a voltmeter?
A. It improves the frequency response
B. It decreases battery consumption in the meter
C. It improves the resolution of the readings
D.
It decreases the loading on circuits being
measured
77
Amateur Radio Practices
G4C01 Which of the following might be
useful in reducing RF interference to audiofrequency devices?
A.
B.
C.
D.
Bypass inductor
Bypass capacitor
Forward-biased diode
Reverse-biased diode
78
Amateur Radio Practices
G4C01 Which of the following might be
useful in reducing RF interference to audiofrequency devices?
A. Bypass inductor
B.
Bypass capacitor
C. Forward-biased diode
D. Reverse-biased diode
79
Amateur Radio Practices
RFI
Occasionally, the RF transmitted from a station will be picked up
in the telephone lines and will be audible on the phone. This is
very common near AM broadcast stations. The telephone line
filter shown here can be used to eliminate RF being picked up
in the telephone line by simply plugging it in line with the
phone (there’s a jack on the end of the boxy part). Some
phones (poorly designed ones) will actually pick up the RF
inside the phone. There is no effective solution for these
phones, short of replacement.
It is also possible for RF to be picked up by PA or stereo systems.
Sideband voice signals will often sound very distorted and CW
can cause a buzzing or clicking. A solid ground on the
transmitter and the PA or stereo system can often correct this.
80
Amateur Radio Practices
Telephone Line Filter
81
Amateur Radio Practices
G4C02 Which of the following should be
installed if a properly operating amateur
station is interfering with a nearby
telephone?
A.
B.
C.
D.
An RFI filter on the transmitter
An RFI filter at the affected telephone
A high pass filter on the transmitter
A high pass filter at the affected telephone
82
Amateur Radio Practices
G4C02 Which of the following should be
installed if a properly operating amateur
station is interfering with a nearby
telephone?
A. An RFI filter on the transmitter
B.
An RFI filter at the affected telephone
C. A high pass filter on the transmitter
D. A high pass filter at the affected telephone
83
Amateur Radio Practices
G4C03 What sound is heard from a publicaddress system if there is interference from
a nearby single-sideband phone transmitter?
A.
B.
C.
D.
A steady hum whenever the transmitter is on the air
On-and-off humming or clicking
Distorted speech
Clearly audible speech
84
Amateur Radio Practices
G4C03 What sound is heard from a publicaddress system if there is interference from
a nearby single-sideband phone transmitter?
A. A steady hum whenever the transmitter is on the air
B. On-and-off humming or clicking
C.
Distorted speech
D. Clearly audible speech
85
Amateur Radio Practices
G4C04 What is the effect on a public-address
system if there is interference from nearby
CW transmitter?
A.
B.
C.
D.
On-and-off humming or clicking
A CW signal at a nearly pure audio frequency
A chirpy CW signal
Severely distorted audio
86
Amateur Radio Practices
G4C04 What is the effect on a public-address
system if there is interference from nearby
CW transmitter?
A.
On-and-off humming or clicking
B. A CW signal at a nearly pure audio frequency
C. A chirpy CW signal
D. Severely distorted audio
87
Amateur Radio Practices
Station Grounding
For a proper RF ground, it’s important to use a heavy
gauge copper (not aluminum) braid or foil and keep
the run length to a minimum. Standard wire, even
heavy gauge, or long runs can cause your ground lead
to act as an antenna and resonate. A good ground
will reduce RFI to other equipment, minimize the risk
of shock and reduce electrical interference. At a
minimum a ground rod should be 8 feet long. This
can be difficult to achieve in some locations and
multiple shorter rods tied together can be used.
88
Amateur Radio Practices
Station Grounding
89
Amateur Radio Practices
G4C05 What might be the problem if you
receive an RF burn when touching your
equipment while transmitting on a HF band,
assuming the equipment is connected to a
ground rod?
A. Flat braid rather than round wire has been used for the
ground wire
B. Insulated wire has been used for the ground wire
C. The ground rod is resonant
D. The ground wire is resonant
90
Amateur Radio Practices
G4C05 What might be the problem if you
receive an RF burn when touching your
equipment while transmitting on a HF band,
assuming the equipment is connected to a
ground rod?
A. Flat braid rather than round wire has been used for the
ground wire
B. Insulated wire has been used for the ground wire
C. The ground rod is resonant
D.
The ground wire is resonant
91
Amateur Radio Practices
G4C06 Which of the following is an
important reason to have a good station
ground?
A.
B.
C.
D.
To reduce the likelihood of RF burns
To reduce the likelihood of electrical shock
To reduce interference
All of these answers are correct
92
Amateur Radio Practices
G4C06 Which of the following is an
important reason to have a good station
ground?
A. To reduce the likelihood of RF burns
B. To reduce the likelihood of electrical shock
C. To reduce interference
D.
All of these answers are correct
93
Amateur Radio Practices
G4C07 What is one good way to avoid stray
RF energy in an amateur station?
A.
B.
C.
D.
Keep the station's ground wire as short as possible
Install an RF filter in series with the ground wire
Use a ground loop for best conductivity
Install a few ferrite beads on the ground wire where it
connects to your station
94
Amateur Radio Practices
G4C07 What is one good way to avoid stray
RF energy in an amateur station?
A.
Keep the station's ground wire as short as
possible
B. Install an RF filter in series with the ground wire
C. Use a ground loop for best conductivity
D. Install a few ferrite beads on the ground wire where it
connects to your station
95
Amateur Radio Practices
G4C08 Which of the following is a reason to
place ferrite beads around audio cables to
reduce common mode RF interference?
A.
B.
C.
D.
They
They
They
They
act as a series inductor
act as a shunt capacitor
lower the impedance of the cable
increase the admittance of the cable
96
Amateur Radio Practices
G4C08 Which of the following is a reason to
place ferrite beads around audio cables to
reduce common mode RF interference?
A.
They act as a series inductor
B. They act as a shunt capacitor
C. They lower the impedance of the cable
D. They increase the admittance of the cable
97
Amateur Radio Practices
G4C09 Which of the following statements
about station grounding is true?
A. The chassis of each piece of station equipment should be
tied together with high-impedance conductors
B. If the chassis of all station equipment is connected with a
good conductor, there is no need to tie them to an earth
ground
C. RF hot spots can occur in a station located above the
ground floor if the equipment is grounded by a long ground
wire
D. A ground loop is an effective way to ground station
equipment
98
Amateur Radio Practices
G4C09 Which of the following statements
about station grounding is true?
A. The chassis of each piece of station equipment should be
tied together with high-impedance conductors
B. If the chassis of all station equipment is connected with a
good conductor, there is no need to tie them to an earth
ground
C.
RF hot spots can occur in a station located
above the ground floor if the equipment is grounded
by a long ground wire
D. A ground loop is an effective way to ground station
equipment
99
Amateur Radio Practices
G4C10 Which of the following is covered in
the National Electrical Code?
A.
B.
C.
D.
Acceptable bandwidth limits
Acceptable modulation limits
Electrical safety inside the ham shack
RF exposure limits of the human body
100
Amateur Radio Practices
G4C10 Which of the following is covered in
the National Electrical Code?
A. Acceptable bandwidth limits
B. Acceptable modulation limits
C.
Electrical safety inside the ham shack
D. RF exposure limits of the human body
101
Amateur Radio Practices
G4C11 Which of the following can cause
unintended rectification of RF signal energy
and can result in interference to your station
as well as nearby radio and TV receivers?
A. Induced currents in conductors that are in poor electrical
contact
B. Induced voltages in conductors that are in good electrical
contact
C. Capacitive coupling of the RF signal to ground
D. Excessive standing wave ratio (SWR) of the transmission
line system
102
Amateur Radio Practices
G4C11 Which of the following can cause
unintended rectification of RF signal energy
and can result in interference to your station
as well as nearby radio and TV receivers?
A.
Induced currents in conductors that are in poor
electrical contact
B. Induced voltages in conductors that are in good electrical
contact
C. Capacitive coupling of the RF signal to ground
D. Excessive standing wave ratio (SWR) of the transmission
line system
103
Amateur Radio Practices
G4C12 What is one cause of broadband radio
frequency interference at an amateur radio
station?
A. Not using a balun or line isolator to feed balanced antennas
B. Lack of rectification of the transmitter's signal in power
conductors
C. Arcing at a poor electrical connection
D. The use of horizontal, rather than vertical antennas
104
Amateur Radio Practices
G4C12 What is one cause of broadband radio
frequency interference at an amateur radio
station?
A. Not using a balun or line isolator to feed balanced antennas
B. Lack of rectification of the transmitter's signal in power
conductors
C.
Arcing at a poor electrical connection
D. The use of horizontal, rather than vertical antennas
105
Amateur Radio Practices
G4C13 How can a ground loop be avoided?
A. Series connect all ground conductors
B. Connect the AC neutral conductor to the ground wire
C. Avoid using lock washers and star washers in making
ground connections
D. Connect all ground conductors to a single point
106
Amateur Radio Practices
G4C13 How can a ground loop be avoided?
A. Series connect all ground conductors
B. Connect the AC neutral conductor to the ground wire
C. Avoid using lock washers and star washers in making
ground connections
D.
Connect all ground conductors to a single point
107
Amateur Radio Practices
G4D01 What is the reason for using a
properly adjusted speech processor with a
single sideband phone transmitter?
A.
B.
C.
D.
It
It
It
It
reduces average transmitter power requirements
reduces unwanted noise pickup from the microphone
improves voice-frequency fidelity
improves signal intelligibility at the receiver
108
Amateur Radio Practices
G4D01 What is the reason for using a
properly adjusted speech processor with a
single sideband phone transmitter?
A. It reduces average transmitter power requirements
B. It reduces unwanted noise pickup from the microphone
C. It improves voice-frequency fidelity
D.
It improves signal intelligibility at the receiver
109
Amateur Radio Practices
G4D02 Which of the following describes how
a speech processor affects a transmitted
single sideband signal?
A.
B.
C.
D.
It
It
It
It
increases the peak power
increases the average power
reduces harmonic distortion
reduces intermodulation distortion
110
Amateur Radio Practices
G4D02 Which of the following describes how
a speech processor affects a transmitted
single sideband signal?
A. It increases the peak power
B.
It increases the average power
C. It reduces harmonic distortion
D. It reduces intermodulation distortion
111
Amateur Radio Practices
G4D03 Which of the following can be the
result of an incorrectly adjusted speech
processor?
A.
B.
C.
D.
Distorted speech
Splatter
Excessive background pickup
All of these answers are correct
112
Amateur Radio Practices
G4D03 Which of the following can be the
result of an incorrectly adjusted speech
processor?
A. Distorted speech
B. Splatter
C. Excessive background pickup
D.
All of these answers are correct
113
Amateur Radio Practices
G4D04 What does an S-meter measure?
A.
B.
C.
D.
Conductance
Impedance
Received signal strength
Transmitter power output
114
Amateur Radio Practices
G4D04 What does an S-meter measure?
A. Conductance
B. Impedance
C.
Received signal strength
D. Transmitter power output
115
Amateur Radio Practices
G4D05 How does an S-meter reading of 20
db over S-9 compare to an S-9 signal,
assuming a properly calibrated S meter?
A.
B.
C.
D.
It
It
It
It
is
is
is
is
10 times weaker
20 times weaker
20 times stronger
100 times stronger
116
Amateur Radio Practices
G4D05 How does an S-meter reading of 20
db over S-9 compare to an S-9 signal,
assuming a properly calibrated S meter?
A. It is 10 times weaker
B. It is 20 times weaker
C. It is 20 times stronger
D.
It is 100 times stronger
117
Amateur Radio Practices
G4D06 Where is an S-meter generally
found?
A.
B.
C.
D.
In
In
In
In
a
a
a
a
receiver
SWR bridge
transmitter
conductance bridge
118
Amateur Radio Practices
G4D06 Where is an S-meter generally
found?
A.
In a receiver
B. In a SWR bridge
C. In a transmitter
D. In a conductance bridge
119
Amateur Radio Practices
Typical Ham RF Connectors
From Left to Right:
N male, N female, PL-259, BNC male, SMA male, SMA female (on HT),
BNC female (on lower radio), SO-238 (on upper radio)
120
Amateur Radio Practices
G4D07 Which of the following describes a
Type-N connector?
A.
B.
C.
D.
A moisture resistant RF connector useful to 10 GHz
A small bayonet connector used for data circuits
A threaded connector used for hydraulic systems
An audio connector used in surround sound installations
121
Amateur Radio Practices
G4D07 Which of the following describes a
Type-N connector?
A.
A moisture resistant RF connector useful to 10
GHz
B. A small bayonet connector used for data circuits
C. A threaded connector used for hydraulic systems
D. An audio connector used in surround sound installations
122
Amateur Radio Practices
G4D08 Which of the following connectors
would be a good choice for a serial data
port?
A.
B.
C.
D.
PL-259
Type N
Type SMA
DB-9
123
Amateur Radio Practices
G4D08 Which of the following connectors
would be a good choice for a serial data
port?
A. PL-259
B. Type N
C. Type SMA
D.
DB-9
124
Amateur Radio Practices
G4D09 Which of these connector types is
commonly used for RF service at frequencies
up to 150 MHz?
A.
B.
C.
D.
Octal
RJ-11
UHF
DB-25
125
Amateur Radio Practices
G4D09 Which of these connector types is
commonly used for RF service at frequencies
up to 150 MHz?
A. Octal
B. RJ-11
C.
UHF
D. DB-25
126
Amateur Radio Practices
G4D10 Which of these connector types is
commonly used for audio signals in amateur
radio stations?
A.
B.
C.
D.
PL-259
BNC
RCA Phono
Type N
127
Amateur Radio Practices
G4D10 Which of these connector types is
commonly used for audio signals in amateur
radio stations?
A. PL-259
B. BNC
C.
RCA Phono
D. Type N
128
Amateur Radio Practices
Anderson Power Poles
G4D11 What is the main reason to use keyed
connectors over non-keyed types?
A.
B.
C.
D.
Prevention of use by unauthorized persons
Reduced chance of damage due to incorrect mating
Higher current carrying capacity
All of these choices are correct
130
Amateur Radio Practices
G4D11 What is the main reason to use keyed
connectors over non-keyed types?
A. Prevention of use by unauthorized persons
B.
Reduced chance of damage due to incorrect
mating
C. Higher current carrying capacity
D. All of these choices are correct
131
Amateur Radio Practices
G4E01 Which of the following emission types
are permissible while operating HF mobile?
A.
B.
C.
D.
CW
SSB
FM
All of these choices are correct
132
Amateur Radio Practices
G4E01 Which of the following emission types
are permissible while operating HF mobile?
A. CW
B. SSB
C. FM
D.
All of these choices are correct
133
Amateur Radio Practices
Mobile Radio Installation
134
Amateur Radio Practices
The power is wired directly to the battery via a fuse on each power lead.
135
Amateur Radio Practices
There is a relay that turns the radio off when the ignition is turned off and
the antenna is mounted on the roof for best performance and shielding for
the occupants
136
Amateur Radio Practices
Using large wires directly to the battery insures there is sufficient power
available with minimal voltage drop and noise. Where a 50 watt VHF
transceiver may draw up to 10 amps, an HF transceiver can draw over 20
amps. Most auto wiring is not designed for this load, particularly cigarette
lighters.
137
Amateur Radio Practices
Mobile Radio Installation
138
Amateur Radio Practices
Would you like Whine with that Cheese?
G4E02 What is alternator whine?
A. A DC emission from the alternator
B. A constant pitched tone or buzz in transmitted or received
audio that occurs whenever the ignition key is in the on
position
C. A tone or buzz in transmitted or received audio that varies
with engine speed
D. A mechanical sound from the alternator indicating current
overload
140
Amateur Radio Practices
G4E02 What is alternator whine?
A. A DC emission from the alternator
B. A constant pitched tone or buzz in transmitted or received
audio that occurs whenever the ignition key is in the on
position
C.
A tone or buzz in transmitted or received audio
that varies with engine speed
D. A mechanical sound from the alternator indicating current
overload
141
Amateur Radio Practices
G4E03 Which of the following power
connections would be the best for a 100watt HF mobile installation?
A. A direct, fused connection
gauge wire
B. A direct, fused connection
using heavy gauge wire
C. A direct, fused connection
D. A direct, fused connection
using resistor wire
to the battery using heavy
to the alternator or generator
to the battery using resistor wire
to the alternator or generator
142
Amateur Radio Practices
G4E03 Which of the following power
connections would be the best for a 100watt HF mobile installation?
A.
A direct, fused connection to the battery using
heavy gauge wire
B. A direct, fused connection to the alternator or generator
using heavy gauge wire
C. A direct, fused connection to the battery using resistor wire
D. A direct, fused connection to the alternator or generator
using resistor wire
143
Amateur Radio Practices
G4E04 Why is it best NOT to draw the DC
power for a 100-watt HF transceiver from an
automobile's cigarette lighter socket?
A. The socket is not wired with an RF-shielded power cable
B. The socket's wiring may be inadequate for the current
being drawn by the transceiver
C. The DC polarity of the socket is reversed from the polarity
of modern HF transceivers
D. The power from the socket is never adequately filtered for
HF transceiver operation
144
Amateur Radio Practices
G4E04 Why is it best NOT to draw the DC
power for a 100-watt HF transceiver from an
automobile's cigarette lighter socket?
A. The socket is not wired with an RF-shielded power cable
B.
The socket's wiring may be inadequate for the
current being drawn by the transceiver
C. The DC polarity of the socket is reversed from the polarity
of modern HF transceivers
D. The power from the socket is never adequately filtered for
HF transceiver operation
145
Amateur Radio Practices
G4E05 Which of the following most limits
the effectiveness of an HF mobile transceiver
operating in the 75 meter band?
A.
B.
C.
D.
"Picket Fencing" signal variation
The wire gauge of the DC power line to the transceiver
The HF mobile antenna system
FCC rules limiting mobile output power on the 75 meter
band
146
Amateur Radio Practices
G4E05 Which of the following most limits
the effectiveness of an HF mobile transceiver
operating in the 75 meter band?
A. "Picket Fencing" signal variation
B. The wire gauge of the DC power line to the transceiver
C.
The HF mobile antenna system
D. FCC rules limiting mobile output power on the 75 meter
band
147
Amateur Radio Practices
G4E06 Which of the following is true of an
emergency generator installation?
A. The generator should be located in a well ventilated area
B. The generator should be insulated from ground
C. Fuel should be stored near the generator for rapid refueling
in case of an emergency
D. All of these choices are correct
148
Amateur Radio Practices
G4E06 Which of the following is true of an
emergency generator installation?
A.
The generator should be located in a well
ventilated area
B. The generator should be insulated from ground
C. Fuel should be stored near the generator for rapid refueling
in case of an emergency
D. All of these choices are correct
149
Amateur Radio Practices
Big Bada Boom
The facility was formerly a large computer/data center with battery room and
emergency generators in Sacramento, CA. The company vacated the
building, moved out the computer equipment but left the battery backup
system behind.
The ventilation for the battery room appeared to be tied to a hydrogen
monitoring system (which is pretty common). The Hydrogen sensor was in
alarm upon emergency responders arriving at the scene (post-explosion).
911 callers reporting the explosion also reported hearing an alarm for 3 days
prior to the explosion. This appears to have been a local alarm as it was not
relayed to the Fire Department. Given how slowly batteries generate
hydrogen gas, it appears the batteries were charging for a long period of
time with no ventilation - the detector was alarming and hydrogen gas
continued to build up until it found an ignition source. The best guess is the
ignition occurred at or near a grounding strap on the battery racks but in a
room full of batteries and electrical equipment, ignition sources are
plentiful...especially when considering the sensitivity of hydrogen.
150
Amateur Radio Practices
Battery Explosion
151
Amateur Radio Practices
G4E07 When might a lead-acid storage
battery give off explosive hydrogen gas?
A.
B.
C.
D.
When
When
When
When
stored for long periods of time
being discharged
being charged
not placed on a level surface
152
Amateur Radio Practices
G4E07 When might a lead-acid storage
battery give off explosive hydrogen gas?
A. When stored for long periods of time
B. When being discharged
C.
When being charged
D. When not placed on a level surface
153
Amateur Radio Practices
Solar panels work on a process called
photovoltaic conversion. The output
voltage from each cell is fixed at 0.5
volts but current output changes with
light intensity. These individual cells
are wired in such a way that they
provide the desired output voltage,
generally from 12 to 48 volts. 12 volt
panels can obviously be used to
power radios or charge batteries (that
power radios) where 48 volt panels
are generally used to charge storage
batteries for larger (residential-sized)
electrical systems. It’s important
when choosing a panel that it is wired
for the correct voltage and can supply
the current necessary.
Solar Panel or
Photovoltaic
Module
154
Amateur Radio Practices
G4E08 What is the name of the process by
which sunlight is changed directly into
electricity?
A.
B.
C.
D.
Photovoltaic conversion
Photon emission
Photosynthesis
Photon decomposition
155
Amateur Radio Practices
G4E08 What is the name of the process by
which sunlight is changed directly into
electricity?
A.
Photovoltaic conversion
B. Photon emission
C. Photosynthesis
D. Photon decomposition
156
Amateur Radio Practices
G4E09 What is the approximate open-circuit
voltage from a modern, well illuminated
photovoltaic cell?
A.
B.
C.
D.
0.02 VDC
0.5 VDC
0.2 VDC
1.38 VDC
157
Amateur Radio Practices
G4E09 What is the approximate open-circuit
voltage from a modern, well illuminated
photovoltaic cell?
A. 0.02 VDC
B.
0.5 VDC
C. 0.2 VDC
D. 1.38 VDC
158
Amateur Radio Practices
G4E10 Which of these materials is used as
the active element of a solar cell?
A.
B.
C.
D.
Doped Silicon
Nickel Hydride
Doped Platinum
Aluminum nitride
159
Amateur Radio Practices
G4E10 Which of these materials is used as
the active element of a solar cell?
A.
Doped Silicon
B. Nickel Hydride
C. Doped Platinum
D. Aluminum nitride
160
Amateur Radio Practices
G4E11 Which of the following is a
disadvantage to using wind power as the
primary source of power for an emergency
station?
A. The conversion efficiency from mechanical energy to
electrical energy is less that 2 percent
B. The voltage and current ratings of such systems are not
compatible with amateur equipment
C. A large energy storage system is needed to supply power
when the wind is not blowing
D. All of these choices are correct
161
Amateur Radio Practices
G4E11 Which of the following is a
disadvantage to using wind power as the
primary source of power for an emergency
station?
A. The conversion efficiency from mechanical energy to
electrical energy is less that 2 percent
B. The voltage and current ratings of such systems are not
compatible with amateur equipment
C.
A large energy storage system is needed to
supply power when the wind is not blowing
D. All of these choices are correct
162
Amateur Radio Practices
G4E12 Which of the following is a primary
reason for not placing a gasoline-fueled
generator inside an occupied area?
A.
B.
C.
D.
Danger of carbon monoxide poisoning
Danger of engine over torque
Lack of oxygen for adequate combustion
Lack of nitrogen for adequate combustion
163
Amateur Radio Practices
G4E12 Which of the following is a primary
reason for not placing a gasoline-fueled
generator inside an occupied area?
A.
Danger of carbon monoxide poisoning
B. Danger of engine over torque
C. Lack of oxygen for adequate combustion
D. Lack of nitrogen for adequate combustion
164
Amateur Radio Practices
G4E13 Why would it be unwise to power
your station by back feeding the output of a
gasoline generator into your house wiring by
connecting the generator through an AC wall
outlet?
A.
B.
C.
D.
It might present a hazard for electric company workers
It is prone to RF interference
It may disconnect your RF ground
None of the above; this is an excellent expedient
165
Amateur Radio Practices
G4E13 Why would it be unwise to power
your station by back feeding the output of a
gasoline generator into your house wiring by
connecting the generator through an AC wall
outlet?
A.
It might present a hazard for electric company
workers
B. It is prone to RF interference
C. It may disconnect your RF ground
D. None of the above; this is an excellent expedient
166
Amateur Radio Practices
G4 - AMATEUR RADIO PRACTICES
[5 Questions - 5 groups]
167
Amateur Radio Practices