問題一覧
1
Which of the following is a common use of coaxial cable?
carry RF signals between a radio and antenna
2
Which instrument is used to measure electrical current?
ammeter
3
What could be used in place of a regular speaker to help you copy signals in a noisy area?
set of headphones
4
Where should a mobile transceiver's power negative connection be made?
at the battery or engine block ground strap
5
Which of the following can be used to enter the operating frequency of a modern transceiver?
the keypad of VFO knob
6
Which of the following measurements are commonly used using a multimeter?
voltage and resistance
7
What signals are used to conduct a two-tone test?
two non-harmonically related audio signal
8
Which of the following can be the result of an incorrectly adjusted speech processor?
all of the choices
9
What does the term "Frequency Stability Over Temperature" mean?
frequency tolerance with respect to a range of temperature measured in PPM or parts per million
10
What does the term "Selectivity” mean?
it is the ability of a receiver to distinguish between a signal and the desired
11
What does the term "Receiver Sensitivity” means?
it is a measure of a receiver’s ability to reproduce very weak signals
12
What safety equipment item should you always add to home built equipment that is powered from 230 volt AC lines?
a fuse or circuit breakers in series with the equipment
13
What is the most important safety precaution to take when putting up an antenna tower?
insulate the base of the tower to avoid lightning strikes
14
To avoid excessively high human exposure to RF fields, how should amateur antennas generally be mounted?
as far away from accessible areas possible
15
What are the frequency limits of the 2-meter band in ITU Region 3?
144.000 - 146.000 MHz
16
What might cause erratic changes in SWR readings?
a loose connection in an antenna or a feed line
17
How is an ammeter usually connected to a circuit?
in series with the circuit
18
What, in general terms, is standing wave ratio (SWR)?
a measure of how well a load is matched to a transmission line
19
What should you do if you receive a report that your station's transmissions are causing splatter or interference on nearby frequencies?
check your transmitter for off-frequency operation or spurious emissions
20
Where must a filter be installed to reduce harmonic emissions?
between the transmitter and the antenna
21
What electrical component is used to connect or disconnect electrical circuits?
switch
22
Which of the following may be useful in correcting a radio frequency interference problem?
all of the choices
23
What popular operating activity involves contacting as many stations as possible during a specified period of time?
contesting
24
What brief statement is often used in place of "CQ" to indicate that you are listening on a repeater?
say your call sign
25
Which of the following is common practice during net operations to get the immediate attention of the net control station when reporting an emergency?
begin your transmission with “priority” or “Emergency” followed by your call sign
26
What is the formula for converting frequency to wavelength in meters?
wavelength in meters equals 300 divided by frequency in megahertz
27
Which of the following describes the common meaning of the term "repeater offset”?
the difference between the repeater’s transmit and receive frequencies
28
Which of the following types of solder is best for radio and electronic use?
rosin-core solder
29
Which of these items would be useful for a hidden transmitter hunt?
a directional antenna
30
What does an antenna tuner do?
it matches the antenna system impedance to the transceiver’s output impedance
31
What is capture effect?
a phenomenon in FM reception in which only the stronger of two signals at, or near , the same frequency will be
32
What is used to test the linearity and output power of an SSB transceiver?
two-tone sine wave test
33
A logic probe has three LED's (Light Emitting Diode), red, green and amber, what does a flashing amber light indicates?
a pulse signal
34
What does a spectrum analyzer test instrument display?
frequency domain waveforms
35
Why do we use a dummy load?
all of the choices
36
What is frequency drift?
all of the choices
37
What is frequency tolerance?
initial deviation of a crystal or oscillator frequency as compared to the absolute at 25 deg. C
38
Which of the following frequencies is in the 12-meter band?
24.940 MHz
39
Which of the following is true concerning access to frequencies?
no one has priority access to frequencies, common courtesy should be a guide
40
How can a ground loop be avoided?
connect all ground contacts to a single point
41
Which of the following can be the result of an improperly adjusted speech processor?
all of the choices
42
Which of the following components should be added to a capacitor to increase the capacitance?
a capacitor in parallel
43
Which frequency is within the 6-meter band?
52.525 MHz
44
Under which of the following circumstances are amateur stations authorized to transmit signals related to broadcasting, program production, or news gathering, assuming no other means is available?
only where such communications directly relate to immediate safety of human life or protection of property
45
Which of the following is a common use for the dual VFO feature on a transceiver?
to permit ease of monitoring the transmit and receive frequencies when they are not the same
46
What is an advantage of a digital voltmeter as compared to an analog voltmeter?
better precision for most uses
47
What could be a symptom of a ground loop somewhere in your station?
you receive reports of “hum” on your station’s transmitter signal
48
What does an S-meter measure?
received signal strength
49
Which of the following phone emissions uses the narrowest frequency bandwidth?
single sideband
50
What is the approximate length for a 1/2-wave dipole antenna cut for 3.550 MHz?
131 feet
51
What is a logic probe?
a probe used for analyzing and troubleshooting logical states
52
An oscilloscope displays signals in what format?
amplitude level and time duration
53
What reading on an SWR meter indicates perfect impedance match between the antenna and the feed line?
1 to 1
54
Which of the following precautions should be taken when measuring circuit resistance with an ohmmeter?
ensure that the circuit is not powered
55
What is the minimum safe distance from a power line when installing an antenna?
1/2 wavelength at the operating frequency
56
What is an instance in which the use of an instrument with analog readout may be preferred over an instrument with a numerical digital readout?
when adjusting tuned circuits
57
What type of filter should be connected to a TV receiver as the first step in trying to prevent RF overload from a nearby 2 M transmitter?
band-reject filter
58
What is the source of a high-pitched whine that varies with engine speed in a mobile transceiver's receive audio?
the alternator
59
Which of the following controls could be used if the voice pitch of a single-sideband signal seems too high or too low?
the receiver RIT clarifier
60
What instrument is used to measure standing wave ratio?
an SWR meter
61
your mobile transceiver does not power up, what might you check first?
the 12-volt fuses
62
In what radio frequency range do 2-meter communications take place?
VHF, very high frequency range
63
What circuit blocks RF energy above and below certain limits?
a band-pass filter
64
Which of the following devices would you need to conduct Amateur Radio communications using a data emission?
computer
65
What is a coaxial cable?
a center wire inside an insulting material covered by the metal sleeve or shield
66
What does a “TR" switch means?
a transmit-receive change-over switch
67
Which of the following is an advantage of a switched-mode power supply as compared to a linear power supply?
the relatively high frequency power oscillator allows the use of small, light weight and low-cost transformers in the switched-mode supply
68
What would be the SWR if you feed a vertical antenna that has a 25-ohm feed point impedance with 50-ohm coaxial cable?
2:01
69
What RF-safety precautions should you take before beginning repairs on an antenna?
be sure to turn off the transmitter and disconnect the feed line
70
What is the best reason to use a headset with an attached microphone and VOX control when using a mobile station?
for safety, hands-free operation
71
What is a device used for radiating electromagnetic signals fed into it from a radio transmiter into space, or for capturing a small portion of the RF energy from pace and then feeding it into a receiver for subsequent processing?
antenna
72
What is an electromechanical device having one or more contacts that are opened and closed by a magnetic field generated by its own built-in electromagnet that can be activated by an external circuit?
relay
73
What type of instrument can be used to accurately measure an RF field?
a calibrated field-strength meter with a calibrated antenna
74
What is the purpose of a transmitter power supply interlock?
to ensure that dangerous voltages are removed if the cabinet is opened
75
What is normally meant by operating a transceiver in “split” mode?
the transceiver is set to different transmit and receive frequencies
76
Which of these connector types is commonly used for audio signals in Amateur Radio stations?
RCA Phono
77
Which HF antenna would be the best to use for minimizing interference?
a unidirectional antenna
78
Which of the following can be determined with a field strength meter?
the radiation pattern of an antenna
79
What are the typical characteristic impedances of coaxial cables used for antenna feed lines at amateur stations?
50 ohm and 75 ohm
80
If you are told your amateur station is causing television interference, what should you do?
connect a high-pass filter to the transmitter output and low-pass filter to the antenna input of the television
81
How many hertz are there in a kilohertz?
1000
82
Approximately how long is the driven element of a Yagi antenna?
1/2 wavelength
83
What could happen to your transceiver if you replace its blown 5 amp AC line fuse with a 30 amp fuse?
the transceiver could use more current than 5 amps and a fire could occur
84
How could you best keep unauthorized persons from using your amateur station at home?
use a key-operated on/off switch in the main power line
85
What is the most important accessory to have for a hand held radio in an emergency?
several sets of charged batteries
86
What may happen if an SSB transmitter is operated with the microphone gain set too high?
it may cause splatter interference to other stations operating near its frequency
87
Most humans can hear sounds in what frequency range?
20 - 20,000 Hz
88
Considering RF safety, what precaution should you take whenever you make adjustments to the feed line of a directional antenna system?
be sure no one can activate the transmitter
89
You are the net control station of a daily HF net, what would you do if the frequency on which you normally meet is in use just before the net begins?
conduct the net on a clear frequency 3 to 5 kHz away from the regular net frequency
90
What is the purpose of the VOX sensitivity control?
to set the audio level at which the transmitter activates
91
What is the best instrument to use to check the signal quality of a CW or single-sideband phone transmitter?
a monitoring oscilloscope
92
Which of the following statements about station grounding is true?
RF hot spots can occur in a station located above the ground floor of the equipment is grounded by a long ground wire
93
If a single-sideband phone transmitter is 100% modulated, what will a speech processor do to the transmitter's power?
it will increase the output PEP
94
Why is it best not to draw the DC power for a 100-Watt HF transceiver from an automobile's cigarette lighter socket?
the socket’s wiring may not be adequate for the current being drawn by the transceiver
95
Grid-dip meter/solid state dip meter measures what parameter?
resonant frequency of an LC tank circuit
96
Where do we use a frequency counter?
all of the choices
97
What is intermodulation interference?
interference caused by the combining several signals in a non-linear device producing new unwanted frequencies
98
What is receiver desensitization?
overloading of a receiver front-end by a strong off-channel signal causing a reduction in sensitivity
99
What is cross-modulation?
the transfer of the amplitude modulation of a strong unwanted carrier onto the wanted carrier caused by non-linearity in
100
What type of electrical circuit is created when a fuse blows?
an open circuit