Extra Question Pool

Where should a shock-absorbing lanyard be attached to a tower when working above ground?

Above the climber's head level
To the belt of the fall-arrest harness
Even with the climber's waist
To the next lowest set of guys

To what should lanyards be attached while climbing?

Antenna mast
Guy brackets
Tower rungs
Tower legs

When must an RF exposure evaluation be performed on an amateur station operating on 80 meters?

An evaluation must always be performed
When the ERP of the station is less than 10 watts
When the station's operating mode is CW
When the output power from the transmitter is less than 100 watts

Which of the following types of equipment are exempt from RF exposure evaluations?

Transceivers with less than 7 watts of RF output
Antennas that radiate only in the near field
Hand-held transceivers sold before May 3, 2021
Dish antennas less than one meter in diameter

What does SAR measure?

Signal attenuation ratio
Signal amplification rating
The rate at which RF energy is absorbed by the body
The rate of RF energy reflected from stationary terrain

What is meant by "100% tie-off" regarding tower safety?

All loose ropes and guys secured to a fixed structure
At least one lanyard attached to the tower at all times
All tools secured to the climber's harness
All circuit breakers feeding power to the tower must be tied closed with tape, cable, or ties

Why are there separate electric (E) and magnetic (H) MPE limits at frequencies below 300 MHz?

The body reacts to electromagnetic radiation from both the E and H fields
Ground reflections and scattering cause the field strength to vary with location
E field and H field radiation intensity peaks can occur at different locations
All these choices are correct

What hazard is created by operating at microwave frequencies?

Microwaves are ionizing radiation
The high gain antennas commonly used can result in high exposure levels
Microwaves are in the frequency range where wave velocity is higher
The extremely high frequency energy can damage the joints of antenna structures

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Each transmitter that produces 20 percent or more of its MPE limit in areas where the total MPE limit is exceeded
Each transmitter operating with a duty cycle greater than 25 percent
Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded
Each transmitter operating with a duty cycle greater than 50 percent

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

300 kHz - 3 MHz
3 - 30 MHz
30 - 300 MHz
300 - 3000 MHz

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Ensure signals from your station are less than the controlled maximum permissible exposure (MPE) limits
Ensure signals from your station are less than the uncontrolled maximum permissible exposure (MPE) limits
Ensure signals from your station are less than the controlled maximum permissible emission (MPE) limits
Ensure signals from your station are less than the uncontrolled maximum permissible emission (MPE) limits

What is the primary function of an external earth connection or ground rod?

Prevent static build up on power lines
Lightning charge dissipation
Reduce RF current flow between pieces of equipment
Protect breaker panel from power surges

What feature of a cardioid pattern antenna makes it useful for direction-finding antennas?

A very sharp peak
A single null
Broadband response
High radiation angle

How can the output voltage of a multiple-turn receiving loop antenna be increased?

By reducing the permeability of the loop shield
By utilizing high impedance wire for the coupling loop
By increasing the number of turns and/or the area enclosed by the loop
All these choices are correct

What type of radiation pattern is created by a single-turn, terminated loop such as a pennant antenna?

Cardioid
Bidirectional
Omnidirectional
Hyperbolic

What is the function of a sense antenna?

It modifies the pattern of a DF antenna to provide a null in only one direction
It increases the sensitivity of a DF antenna array
It allows DF antennas to receive signals at different vertical angles
It provides diversity reception that cancels multipath signals

What is the function of a Beverage antenna's termination resistor?

Increase the front-to-side ratio
Absorb signals from the reverse direction
Decrease SWR bandwidth
Eliminate harmonic reception

What indicates the correct value of terminating resistance for a Beverage antenna?

Maximum feed point DC resistance at the center of the desired frequency range
Minimum low-angle front-to-back ratio at the design frequency
Maximum DC current in the terminating resistor
Minimum variation in SWR over the desired frequency range

What challenge is presented by a small wire-loop antenna for direction finding?

It has a bidirectional null pattern
It does not have a clearly defined null
It is practical for use only on VHF and higher bands
All these choices are correct

What is the purpose of placing an electrostatic shield around a small-loop direction-finding antenna?

It adds capacitive loading, increasing the bandwidth of the antenna
It eliminates unbalanced capacitive coupling to the antenna's surroundings, improving the depth of its nulls
It eliminates tracking errors caused by strong out-of-band signals
It increases signal strength by providing a better match to the feed line

What is receiving directivity factor (RDF)?

Forward gain compared to the gain in the reverse direction
Relative directivity compared to isotropic
Relative directivity compared to a dipole
Peak antenna gain compared to average gain over the hemisphere around and above the antenna

Which is generally true for 160- and 80-meter receiving antennas?

Atmospheric noise is so high that directivity is much more important than losses
They must be erected at least 1/2 wavelength above the ground to attain good directivity
Low loss coax transmission line is essential for good performance
All these choices are correct

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Its overall length must not exceed 1/4 wavelength
It must be mounted more than 1 wavelength above ground
It should be configured as a four-sided loop
It should be at least one wavelength long

In what units are the wavelength scales on a Smith chart calibrated?

In fractions of transmission line electrical frequency
In fractions of transmission line electrical wavelength
In fractions of antenna electrical wavelength
In fractions of antenna electrical frequency

What do the arcs on a Smith chart represent?

Frequency
SWR
Points with constant resistance
Points with constant reactance

What third family of circles is often added to a Smith chart during the process of designing impedance matching networks?

Constant-SWR circles
Transmission line length circles
Coaxial-length circles
Radiation-pattern circles

How is a Smith chart normalized?

Reassign the reactance axis with resistance values
Reassign the resistance axis with reactance values
Reassign the prime center's impedance value
Reassign the prime center to the reactance axis

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

The reactance axis
The current axis
The voltage axis
The resistance axis

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Prime axis
Reactance axis
Impedance axis
Polar axis

Which of the following is a common use for a Smith chart?

Determine the length and position of an impedance matching stub
Determine the impedance of a transmission line, given the physical dimensions
Determine the gain of an antenna given the physical and electrical parameters
Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials

What are the two families of circles and arcs that make up a Smith chart?

Inductance and capacitance
Reactance and voltage
Resistance and reactance
Voltage and impedance

Which of the following is often determined using a Smith chart?

Beam headings and radiation patterns
Satellite azimuth and elevation bearings
Impedance and SWR values in transmission lines
Point-to-point propagation reliability as a function of frequency

What type of coordinate system is used in a Smith chart?

Voltage circles and current arcs
Resistance circles and reactance arcs
Voltage chords and current chords
Resistance lines and reactance chords

Which of the following can be calculated using a Smith chart?

Impedance along transmission lines
Radiation resistance
Antenna radiation pattern
Radio propagation

What impedance does a 1/4-wavelength transmission line present to an RF generator when the line is open at the far end?

The same as the characteristic impedance of the line
The same as the input impedance to the generator
Very high impedance
Very low impedance

What impedance does a 1/8-wavelength transmission line present to an RF generator when the line is open at the far end?

The same as the characteristic impedance of the line
An inductive reactance
A capacitive reactance
Infinite

What impedance does a 1/8-wavelength transmission line present to an RF generator when the line is shorted at the far end?

A capacitive reactance
The same as the characteristic impedance of the line
An inductive reactance
Zero

What impedance does a 1/4-wavelength transmission line present to an RF generator when the line is shorted at the far end?

Very high impedance
Very low impedance
The same as the characteristic impedance of the transmission line
The same as the generator output impedance

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric coaxial cable, assuming all other parameters are the same?

Foam dielectric coaxial cable has lower safe maximum operating voltage
Foam dielectric coaxial cable has lower loss per unit of length
Foam dielectric coaxial cable has higher velocity factor
All these choices are correct

How does parallel conductor transmission line compare to coaxial cable with a plastic dielectric?

Lower loss
Higher SWR
Smaller reflection coefficient
Lower velocity factor

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

7.0 meters
8.5 meters
10.6 meters
13.3 meters

What is microstrip?

Special shielding material designed for microwave frequencies
Miniature coax used for low power applications
Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies

What impedance does a 1/2-wavelength transmission line present to an RF generator when the line is shorted at the far end?

Very high impedance
Very low impedance
The same as the characteristic impedance of the line
The same as the output impedance of the RF generator

Why is the electrical length of a coaxial cable longer than its physical length?

Skin effect is less pronounced in the coaxial cable
Skin effect is more pronounced in the coaxial cable
Electromagnetic waves move faster in coaxial cable than in air
Electromagnetic waves move more slowly in a coaxial cable than in air

Which of the following has the biggest effect on the velocity factor of a transmission line?

The characteristic impedance
The transmission line length
The insulating dielectric material
The center conductor resistivity

What is the velocity factor of a transmission line?

The ratio of its characteristic impedance to its termination impedance
The ratio of its termination impedance to its characteristic impedance
The velocity of a wave in the transmission line multiplied by the velocity of light in a vacuum
The velocity of a wave in the transmission line divided by the velocity of light in a vacuum

What is the purpose of using multiple driven elements connected through phasing lines?

To control the antenna's radiation pattern
To prevent harmonic radiation from the transmitter
To allow single-band antennas to operate on other bands
To create a low-angle radiation pattern

Which matching system places an inductance across the feed point of a vertical monopole antenna?

Gamma
Shunt-fed
Beta or hairpin
T-match

Which of the following is used to shunt feed a grounded tower at its base?

Double-bazooka match
Beta or hairpin match
Gamma match
All these choices are correct

What is a use for a Wilkinson divider?

To divide the operating frequency of a transmitter signal so it can be used on a lower frequency band
To feed high-impedance antennas from a low-impedance source
To divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
To divide the frequency of the input to a counter to increase its frequency range

What parameter describes the interaction of a load and transmission line?

Characteristic impedance
Reflection coefficient
Velocity factor
Dielectric constant

Which of these transmission line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm feed point impedance to a 50-ohm transmission line?

50 ohms
62 ohms
75 ohms
90 ohms

What Yagi driven element feed point impedance is required to use a beta or hairpin matching system?

Capacitive (driven element electrically shorter than 1/2 wavelength)
Inductive (driven element electrically longer than 1/2 wavelength)
Purely resistive
Purely reactive

What is the purpose of the series capacitor in a gamma match?

To provide DC isolation between the feed line and the antenna
To cancel unwanted inductive reactance
To provide a rejection notch that prevents the radiation of harmonics
To transform the antenna impedance to a higher value

What matching system uses a short length of transmission line connected in parallel with the feed line at or near the feed point?

Gamma match
Delta match
T-match
Stub match

What antenna matching system matches coaxial cable to an antenna by connecting the shield to the center of the antenna and the conductor a fraction of a wavelength to one side?

Gamma match
Delta match
T-match
Stub match

Which matching system for Yagi antennas requires the driven element to be insulated from the boom?

Gamma
Beta or hairpin
Shunt-fed
T-match

What is the purpose of making a Yagi's parasitic elements either longer or shorter than resonance?

Wind torque cancellation
Mechanical balance
Control of phase shift
Minimize losses

Why do most two-element Yagis with normal spacing have a reflector instead of a director?

Lower SWR
Higher receiving directivity factor
Greater front-to-side
Higher gain

How does radiation resistance of a base-fed whip antenna change below its resonant frequency?

Radiation resistance increases
Radiation resistance decreases
Radiation resistance becomes imaginary
Radiation resistance does not depend on frequency

What is the function of a loading coil in an electrically short antenna?

To increase the SWR bandwidth by increasing net reactance
To lower the losses
To lower the Q
To resonate the antenna by cancelling the capacitive reactance

What happens as the Q of an antenna increases?

SWR bandwidth increases
SWR bandwidth decreases
Gain is reduced
More common-mode current is present on the feed line

What is an advantage of top loading an electrically short HF vertical antenna?

Lower Q
Greater structural strength
Higher losses
Improved radiation efficiency

What happens to SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

It is increased
It is decreased
It is unchanged if the loading coil is located at the feed point
It is unchanged if the loading coil is located at a voltage maximum point

Approximately how long is a Yagi's driven element?

234 divided by frequency in MHz
1005 divided by frequency in MHz
1/4 wavelength
1/2 wavelength

Why should antenna loading coils have a high ratio of reactance to resistance?

To swamp out harmonics
To lower the radiation angle
To maximize efficiency
To minimize the Q

What is the most efficient location for a loading coil on an electrically short whip?

Near the center of the vertical radiator
As low as possible on the vertical radiator
At a voltage maximum
At a voltage null

How can two linearly polarized Yagi antennas be used to produce circular polarization?

Stack two Yagis to form an array with the respective elements in parallel planes fed 90 degrees out of phase
Stack two Yagis to form an array with the respective elements in parallel planes fed in phase
Arrange two Yagis on the same axis and perpendicular to each other with the driven elements at the same point on the boom and fed 90 degrees out of phase
Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase

How much does the gain of an ideal parabolic reflector antenna increase when the operating frequency is doubled?

2 dB
3 dB
4 dB
6 dB

How does the radiation pattern of a horizontally-polarized antenna mounted above a long slope compare with the same antenna mounted above flat ground?

The main lobe takeoff angle increases in the downhill direction
The main lobe takeoff angle decreases in the downhill direction
The horizontal beamwidth decreases in the downhill direction
The horizontal beamwidth increases in the uphill direction

How does the radiation pattern of a horizontally polarized antenna vary with increasing height above ground?

The takeoff angle of the lowest elevation lobe increases
The takeoff angle of the lowest elevation lobe decreases
The horizontal beamwidth increases
The horizontal beamwidth decreases

Which of the following describes an extended double Zepp antenna?

An end-fed full-wave dipole antenna
A center-fed 1.5-wavelength dipole antenna
A center-fed 1.25-wavelength dipole antenna
An end-fed 2-wavelength dipole antenna

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Radiation at low angles decreases
Additional lobes appear at higher elevation angles
Separate elevation lobes will combine into a single lobe
Radiation at low angles increases

Which of the following describes a Zepp antenna?

A horizontal array capable of quickly changing the direction of maximum radiation by changing phasing lines
An end-fed half-wavelength dipole
An omni-directional antenna commonly used for satellite communications
A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines

Which of the following describes a G5RV antenna?

A wire antenna center-fed through a specific length of open-wire line connected to a balun and coaxial feed line
A multi-band trap antenna
A phased array antenna consisting of multiple loops
A wide band dipole using shorted coaxial cable for the radiating elements and fed with a 4:1 balun

What is a folded dipole antenna?

A dipole one-quarter wavelength long
A center-fed dipole with the ends folded down 90 degrees at the midpoint of each side
A half-wave dipole with an additional parallel wire connecting its two ends
A dipole configured to provide forward gain

What is the approximate feed point impedance at the center of a two-wire half-wave folded dipole antenna?

300 ohms
72 ohms
50 ohms
450 ohms

What is the effect of adding a terminating resistor to a rhombic or long-wire antenna?

It reflects the standing waves on the antenna elements back to the transmitter
It changes the radiation pattern from bidirectional to unidirectional
It changes the radiation pattern from horizontal to vertical polarization
It decreases the ground loss

What is the purpose of feeding an off-center-fed dipole (OCFD) between the center and one end instead of at the midpoint?

To create a similar feed point impedance on multiple bands
To suppress off-center lobes at higher frequencies
To resonate the antenna across a wider range of frequencies
To reduce common-mode current coupling on the feed line shield

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Fewer lobes form with the major lobes increasing closer to broadside to the wire
Additional lobes form with major lobes increasingly aligned with the axis of the antenna
The elevation angle increases, and the front-to-rear ratio decreases
The elevation angle increases, while the front-to-rear ratio is unaffected

What type of radiation pattern is created by two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

Omni-directional
Cardioid
A figure-eight broadside to the axis of the array
A figure-eight end-fire along the axis of the array

What type of radiation pattern is created by two 1/4-wavelength vertical antennas spaced 1/4-wavelength apart and fed 90 degrees out of phase?

Cardioid
A figure-eight end-fire along the axis of the array
A figure-eight broadside to the axis of the array
Omni-directional

What type of radiation pattern is created by two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Cardioid
Omni-directional
A figure-eight broadside to the axis of the array
A figure-eight oriented along the axis of the array

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Ground conductivity will not be accurately modeled
The resulting design will favor radiation of harmonic energy
The computed feed point impedance may be incorrect
The antenna will become mechanically unstable

What is the principle of a Method of Moments analysis?

A wire is modeled as a series of segments, each having a uniform value of current
A wire is modeled as a single sine-wave current generator
A wire is modeled as a single sine-wave voltage source
A wire is modeled as a series of segments, each having a distinct value of voltage across it

What type of analysis is commonly used for modeling antennas?

Graphical analysis
Method of Moments
Mutual impedance analysis
Calculus differentiation with respect to physical properties

What is the far field of an antenna?

The region of the ionosphere where radiated power is not refracted
The region where radiated power dissipates over a specified time period
The region where radiated field strengths are constant
The region where the shape of the radiation pattern no longer varies with distance

What is the difference in radiated power between a lossless antenna with gain and an isotropic radiator driven by the same power?

The power radiated from the directional antenna is increased by the gain of the antenna
The power radiated from the directional antenna is stronger by its front-to-back ratio
They are the same
The power radiated from the isotropic radiator is 2.15 dB greater than that from the directional antenna

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

45 degrees
75 degrees
7.5 degrees
25 degrees

What type of antenna pattern is shown in Figure E9-2?

Elevation
Azimuth
Near field
Polarization

What is the front-to-back ratio of the radiation pattern shown in Figure E9-2?

15 dB
28 dB
3 dB
38 dB

What is the front-to-side ratio of the antenna radiation pattern shown in Figure E9-1?

12 dB
24 dB
18 dB
14 dB

What is the front-to-back ratio of the antenna radiation pattern shown in Figure E9-1?

36 dB
14 dB
24 dB
18 dB

What is the 3 dB beamwidth of the antenna radiation pattern shown in Figure E9-1?

75 degrees
50 degrees
25 degrees
30 degrees

How much gain does an antenna have compared to a half-wavelength dipole if it has 6 dB gain over an isotropic radiator?

3.85 dB
6.0 dB
8.15 dB
2.79 dB

Which of the following determines ground losses for a ground-mounted vertical antenna operating on HF?

The standing wave ratio
Distance from the transmitter
Soil conductivity
Take-off angle

Which of the following improves the efficiency of a ground-mounted quarter-wave vertical antenna?

Installing a ground radial system
Isolating the coax shield from ground
Shortening the radiating element
All these choices are correct

What is antenna efficiency?

Radiation resistance divided by transmission resistance
Radiation resistance divided by total resistance
Total resistance divided by radiation resistance
Effective radiated power divided by transmitter output

Which frequency band has the smallest first Fresnel zone?

5.8 GHz
3.4 GHz
2.4 GHz
900 MHz

What is the effective isotropic radiated power (EIRP) of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

159 watts
252 watts
632 watts
63.2 watts

What is the effective radiated power (ERP) of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

317 watts
2,000 watts
126 watts
300 watts

What does the term "foreground gain" mean?

The change in signal strength caused by grounding the antenna
The gain of the antenna with respect to a dipole at ground level
To force net gain to 0 dB by grounding part of the antenna
An increase in signal strength from ground reflections in the environment of the antenna

Which of the following factors affect the feed point impedance of an antenna?

Transmission line length
Antenna height
The settings of an antenna tuner at the transmitter
The input power level

What term describing total radiated power takes into account all gains and losses?

Power factor
Half-power bandwidth
Effective radiated power
Apparent power

What is the effective radiated power (ERP) of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

469 watts
78.7 watts
420 watts
286 watts

What is an isotropic radiator?

A calibrated, unidirectional antenna used to make precise antenna gain measurements
An omnidirectional, horizontally polarized, precisely calibrated antenna used to make field measurements of antenna gain
A hypothetical, lossless antenna having equal radiation intensity in all directions used as a reference for antenna gain
A spacecraft antenna used to direct signals toward Earth

What is one advantage of using ASCII code for data communications?

It includes built-in error correction features
It contains fewer information bits per character than any other code
It is possible to transmit both uppercase and lowercase text
It uses one character as a shift code to send numeric and special characters

What are some of the differences between the Baudot digital code and ASCII?

Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

What is considered an acceptable maximum IMD level for an idling PSK signal?

+5 dB
+10 dB
+15 dB
-30 dB

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Signal-to-noise ratio
Baud error rate
Repeat Request Rate (RRR)
Intermodulation Distortion (IMD)

What is a common cause of overmodulation of AFSK signals?

Excessive numbers of retries
Excessive frequency deviation
Bit errors in the modem
Excessive transmit audio levels

What is the advantage of including parity bits in ASCII characters?

Faster transmission rate
Signal-to-noise ratio is improved
A larger character set is available
Some types of errors can be detected

What is the most common method of reducing key clicks?

Increase keying waveform rise and fall times
Insert low-pass filters at the transmitter output
Reduce keying waveform rise and fall times
Insert high-pass filters at the transmitter output

What is the primary effect of extremely short rise or fall time on a CW signal?

More difficult to copy
The generation of RF harmonics
The generation of key clicks
More difficult to tune

Which describes spread spectrum frequency hopping?

If interference is detected by the receiver, it will signal the transmitter to change frequencies
RF signals are clipped to generate a wide band of harmonics which provides redundancy to correct errors
A binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
Rapidly varying the frequency of a transmitted signal according to a pseudorandom sequence

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

Frequency hopping
Direct sequence
Binary phase-shift keying
Phase compandored spread spectrum

Why are received spread spectrum signals resistant to interference?

Signals not using the spread spectrum algorithm are suppressed in the receiver
The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
Built-in error correction codes minimize interference
If the receiver detects interference, it will signal the transmitter to change frequencies

What technique do individual nodes use to form a mesh network?

Forward error correction and Viterbi codes
Acting as store-and-forward digipeaters
Discovery and link establishment protocols
Custom code plugs for the local trunking systems

What type of addresses do nodes have in a mesh network?

Email
Trust server
Internet Protocol (IP)
Talk group

What is described by the constellation diagram of a QAM or QPSK signal?

How many carriers may be present at the same time
The possible phase and amplitude states for each symbol
Frequency response of the signal stream
The number of bits used for error correction in the protocol

What factors affect the bandwidth of a transmitted CW signal?

IF bandwidth and Q
Modulation index and output power
Keying speed and shape factor (rise and fall time)
All these choices are correct

What is the relationship between symbol rate and baud?

They are the same
Baud is twice the symbol rate
Baud rate is half the symbol rate
The relationship depends on the specific code used

How can data rate be increased without increasing bandwidth?

It is impossible
Increasing analog-to-digital conversion resolution
Using a more efficient digital code
Using forward error correction

Which digital code allows only one bit to change between sequential code values?

Binary Coded Decimal Code
Extended Binary Coded Decimal Interchange Code
Extended ASCII
Gray code

How does ARQ accomplish error correction?

Special binary codes provide automatic correction
Special polynomial codes provide automatic correction
If errors are detected, redundant data is substituted
If errors are detected, a retransmission is requested

What is the bandwidth of a 4,800-Hz frequency shift, 9,600-baud ASCII FM transmission?

15.36 kHz
9.6 kHz
4.8 kHz
5.76 kHz

What is the bandwidth of an FT8 signal?

10 Hz
50 Hz
600 Hz
2.4 kHz

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

13 Hz
26 Hz
52 Hz
104 Hz

What technique minimizes the bandwidth of a PSK31 signal?

Zero-sum character encoding
Reed-Solomon character encoding
Use of sinusoidal data pulses
Use of linear data pulses

Why should the phase of a PSK signal be changed at the zero crossing of the RF signal?

To minimize bandwidth
To simplify modulation
To improve carrier suppression
All these choices are correct

What is the definition of symbol rate in a digital transmission?

The number of control characters in a message packet
The maximum rate at which the forward error correction code can make corrections
The rate at which the waveform changes to convey information
The number of characters carried per second by the station-to-station link

What is Quadrature Amplitude Modulation or QAM?

A technique for digital data compression used in digital television which removes redundancy in the data by comparing bit amplitudes
Transmission of data by modulating the amplitude of two carriers of the same frequency but 90 degrees out of phase
A method of performing single sideband modulation by shifting the phase of the carrier and modulation components of the signal
A technique for analog modulation of television video signals using phase modulation and compression

What is digital time division multiplexing?

Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
Two or more signals are arranged to share discrete time slots of a data transmission
Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
Two or more signals are quadrature modulated to increase bandwidth efficiency

What is frequency division multiplexing (FDM)?

The transmitted signal jumps from band to band at a predetermined rate
Dividing the transmitted signal into separate frequency bands that each carry a different data stream
The transmitted signal is divided into packets of information
Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

What is deviation ratio?

The ratio of the audio modulating frequency to the center carrier frequency
The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
The ratio of the carrier center frequency to the audio modulating frequency
The ratio of the highest audio modulating frequency to the average audio modulating frequency

What describes orthogonal frequency-division multiplexing (OFDM)?

A frequency modulation technique that uses non-harmonically related frequencies
A bandwidth compression technique using Fourier transforms
A digital mode for narrow-band, slow-speed transmissions
A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference

Orthogonal frequency-division multiplexing (OFDM) is a technique used for which types of amateur communication?

Digital modes
Extremely low-power contacts
EME
OFDM signals are not allowed on amateur bands

What is the deviation ratio of an FM phone signal having a maximum frequency swing of plus or minus 7.5 kHz if the highest modulation frequency is 3.5 kHz?

2.14
0.214
0.47
47

What is the deviation ratio of an FM phone signal having a maximum frequency swing of plus or minus 5 kHz if the highest modulation frequency is 3 kHz?

6
0.167
0.6
1.67

What is the modulation index of an FM phone signal having a maximum carrier deviation of plus or minus 6 kHz if the highest modulating frequency is 2 kHz?

0.3
3
0.6
6

What is the modulation index of an FM phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency if the highest modulating frequency is 1000 Hz?

3
0.3
6
0.6

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

It increases as the RF carrier frequency increases
It decreases as the RF carrier frequency increases
It varies with the square root of the RF carrier frequency
It does not depend on the RF carrier frequency

What is the modulation index of an FM signal?

The ratio of frequency deviation to modulating signal frequency
The ratio of modulating signal amplitude to frequency deviation
The modulating signal frequency divided by the bandwidth of the transmitted signal
The bandwidth of the transmitted signal divided by the modulating signal frequency

Which of the following is a measure of the quality of an analog-to-digital converter?

Total harmonic distortion
Peak envelope power
Reciprocal mixing
Power factor

What is the purpose of a low-pass filter used at the output of a digital-to-analog converter?

Lower the input bandwidth to increase the effective resolution
Improve accuracy by removing out-of-sequence codes from the input
Remove spurious sampling artifacts from the output signal
All these choices are correct

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

8
8 multiplied by the gain of the input amplifier
256 divided by the gain of the input amplifier
256

Why are direct or flash conversion analog-to-digital converters used for a software defined radio?

Very low power consumption decreases frequency drift
Immunity to out-of-sequence coding reduces spurious responses
Very high speed allows digitizing high frequencies
All these choices are correct

What determines the PEP-to-average power ratio of an unprocessed single-sideband phone signal?

The frequency of the modulating signal
Speech characteristics
The degree of carrier suppression
Amplifier gain

What is the approximate ratio of PEP-to-average power in an unprocessed single-sideband phone signal?

2.5 to 1
25 to 1
1 to 1
13 to 1

What is the benefit of making voltage measurements with a true-RMS calculating meter?

An inverse Fourier transform can be used
The signal's RMS noise factor is also calculated
The calculated RMS value can be converted directly into phasor form
RMS is measured for both sinusoidal and non-sinusoidal signals

What is "dither" with respect to analog-to-digital converters?

An abnormal condition where the converter cannot settle on a value to represent the signal
A small amount of noise added to the input signal to reduce quantization noise
An error caused by irregular quantization step size
A method of decimation by randomly skipping samples

Which of the following describes a signal in the time domain?

Power at intervals of phase
Amplitude at different times
Frequency at different times
Discrete impulses in time order

Which of the following is a type of analog-to-digital conversion?

Successive approximation
Harmonic regeneration
Level shifting
Phase reversal

What technique shows that a square wave is made up of a sine wave and its odd harmonics?

Fourier analysis
Vector analysis
Numerical analysis
Differential analysis

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Use a GPS signal reference
Use a rubidium stabilized reference oscillator
Use a temperature-controlled high Q dielectric resonator
All these choices are correct

Which of the following ensures that a crystal oscillator operates on the frequency specified by the crystal manufacturer?

Provide the crystal with a specified parallel inductance
Provide the crystal with a specified parallel capacitance
Bias the crystal at a specified voltage
Bias the crystal at a specified current

What are the major spectral impurity components of direct digital synthesizers?

Broadband noise
Digital conversion noise
Spurious signals at discrete frequencies
Harmonics of the local oscillator

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

The phase relationship between a reference oscillator and the output waveform
Amplitude values that represent the desired waveform
The phase relationship between a voltage-controlled oscillator and the output waveform
Frequently used receiver and transmitter frequencies

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital-to-analog converter, and a low-pass anti-alias filter?

A direct digital synthesizer
A hybrid synthesizer
A phase-locked loop synthesizer
A direct conversion synthesizer

Which of the following components can be used to reduce thermal drift in crystal oscillators?

NP0 capacitors
Toroidal inductors
Wirewound resistors
Non-inductive resistors

How can an oscillator's microphonic responses be reduced?

Use NP0 capacitors
Reduce noise on the oscillator's power supply
Increase the gain
Mechanically isolate the oscillator circuitry from its enclosure

Which of these functions can be performed by a phase-locked loop?

Wide-band AF and RF power amplification
Frequency synthesis and FM demodulation
Photovoltaic conversion and optical coupling
Comparison of two digital input signals and digital pulse counting

How is positive feedback supplied in a Pierce oscillator?

Through a tapped coil
Through link coupling
Through a neutralizing capacitor
Through a quartz crystal

How is positive feedback supplied in a Colpitts oscillator?

Through a tapped coil
Through link coupling
Through a capacitive divider
Through a neutralizing capacitor

What is a phase-locked loop?

An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
An electronic circuit also known as a monostable multivibrator
An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
An electronic circuit consisting of a precision push-pull amplifier with a differential phase input

What is a microphonic?

An IC used for amplifying microphone signals
Distortion caused by RF pickup on the microphone cable
Changes in oscillator frequency caused by mechanical vibration
Excess loading of the microphone by an oscillator

What are three common oscillator circuits?

Taft, Pierce, and negative feedback
Pierce, Fenner, and Beane
Taft, Hartley, and Pierce
Colpitts, Hartley, and Pierce

What is an operational amplifier?

A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
A digital audio amplifier whose characteristics are determined by components external to the amplifier
An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
A RF amplifier used in the UHF and microwave regions

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3,300 ohms and RF is 47 kilohms?

28
14
7
0.07

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1,800 ohms and RF is 68 kilohms?

1
0.03
38
76

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1,000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

0.23 volts
2.3 volts
-0.23 volts
-2.3 volts

How does the gain of an ideal operational amplifier vary with frequency?

It increases linearly with increasing frequency
It decreases linearly with increasing frequency
It decreases logarithmically with increasing frequency
It does not vary with frequency

What voltage gain can be expected from the circuit in Figure E7-3 when R1 is 10 ohms and RF is 470 ohms?

0.21
4700
47
24

What is the gain-bandwidth of an operational amplifier?

The maximum frequency for a filter circuit using that type of amplifier
The frequency at which the open-loop gain of the amplifier equals one
The gain of the amplifier at a filter's cutoff frequency
The frequency at which the amplifier's offset voltage is zero

How can unwanted ringing and audio instability be prevented in an op-amp audio filter?

Restrict both gain and Q
Restrict gain but increase Q
Restrict Q but increase gain
Increase both gain and Q

What is meant by the term "op-amp input offset voltage"?

The output voltage of the op-amp minus its input voltage
The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
The differential input voltage needed to bring the open loop output voltage to zero
The potential between the amplifier input terminals of the op-amp in an open loop condition

What is the typical input impedance of an op-amp?

100 ohms
10,000 ohms
Very low
Very high

What is the frequency response of the circuit in E7-3 if a capacitor is added across the feedback resistor?

High-pass filter
Low-pass filter
Band-pass filter
Notch filter

What is the typical output impedance of an op-amp?

Very low
Very high
100 ohms
10,000 ohms

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Higher data rate
More taps
Lower Q
Double-precision math routines

What is the function of taps in a digital signal processing filter?

To reduce excess signal pressure levels
Provide access for debugging software
Select the point at which baseband signals are generated
Provide incremental signal delays for filter algorithms

Which of the following is generally true of Finite Impulse Response (FIR) filters?

FIR filters can delay all frequency components of the signal by the same amount
FIR filters are easier to implement for a given set of passband rolloff requirements
FIR filters can respond faster to impulses
All these choices are correct

What sets the minimum detectable signal level for a direct-sampling software defined receiver in the absence of atmospheric or thermal noise?

Sample clock phase noise
Reference voltage level and sample width in bits
Data storage transfer rate
Missing codes and jitter

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a direct-sampling software defined radio (SDR)?

Sample rate
Sample width in bits
Integral non-linearity
Differential non-linearity

Why is an anti-aliasing filter required in a decimator?

It removes high-frequency signal components that would otherwise be reproduced as lower frequency components
It peaks the response of the decimator, improving bandwidth
It removes low-frequency signal components to eliminate the need for DC restoration
It notches out the sampling frequency to avoid sampling errors

What is the function of decimation?

Converting data to binary-coded decimal form
Reducing the effective sample rate by removing samples
Attenuating the signal
Removing unnecessary significant digits

What function is performed by a Fast Fourier Transform?

Converting analog signals to digital form
Converting digital signals to analog form
Converting signals from the time domain to the frequency domain
Converting signals from the frequency domain to the time domain

What is the minimum number of bits required to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

4 bits
6 bits
8 bits
10 bits

How frequently must an analog signal be sampled to be accurately reproduced?

At least half the rate of the highest frequency component of the signal
At least twice the rate of the highest frequency component of the signal
At the same rate as the highest frequency component of the signal
At four times the rate of the highest frequency component of the signal

Which method generates an SSB signal using digital signal processing?

Mixing products are converted to voltages and subtracted by adder circuits
A frequency synthesizer removes unwanted sidebands
Varying quartz crystal characteristics are emulated in digital form
Signals are combined in quadrature phase relationship

What type of digital signal processing filter is used to generate an SSB signal?

An adaptive filter
A notch filter
A Hilbert-transform filter
An elliptical filter

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

An adaptive filter
A crystal-lattice filter
A Hilbert-transform filter
A phase-inverting filter

What is meant by "direct sampling" in software defined radios?

Software is converted from source code to object code during operation of the receiver
I and Q signals are generated by digital processing without the use of RF amplification
Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
A switching mixer is used to generate I and Q signals directly from the RF input

Which type of detector is used for demodulating SSB signals?

Discriminator
Phase detector
Product detector
Phase comparator

How does a diode envelope detector function?

By rectification and filtering of RF signals
By breakdown of the Zener voltage
By mixing signals with noise in the transition region of the diode
By sensing the change of reactance in the diode with respect to frequency

What occurs when the input signal levels to a mixer are too high?

Spurious mixer products are generated
Mixer blanking occurs
Automatic limiting occurs
Excessive AGC voltage levels are generated

What are the principal frequencies that appear at the output of a mixer?

Two and four times the input frequency
The square root of the product of input frequencies
The two input frequencies along with their sum and difference frequencies
1.414 and 0.707 times the input frequency

What is meant by the term "baseband" in radio communications?

The lowest frequency band that the transmitter or receiver covers
The frequency range occupied by a message signal prior to modulation
The unmodulated bandwidth of the transmitted signal
The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency

Why is de-emphasis used in FM communications receivers?

For compatibility with transmitters using phase modulation
To reduce impulse noise reception
For higher efficiency
To remove third-order distortion products

What is added to an FM speech channel to boost the higher audio frequencies?

A de-emphasis network
A harmonic enhancer
A heterodyne enhancer
A pre-emphasis network

What is one way to produce a single-sideband phone signal?

Use a balanced modulator followed by a filter
Use a reactance modulator followed by a mixer
Use a loop modulator followed by a mixer
Use a product detector with a DSB signal

What is a frequency discriminator?

An FM generator circuit
A circuit for filtering closely adjacent signals
An automatic band-switching circuit
A circuit for detecting FM signals

What is the function of a reactance modulator?

Produce PM or FM signals by varying a resistance
Produce AM signals by varying an inductance
Produce AM signals by varying a resistance
Produce PM or FM signals by varying a capacitance

Which of the following can be used to generate FM phone signals?

Balanced modulation of the audio amplifier
Reactance modulation of a local oscillator
Reactance modulation of the final amplifier
Balanced modulation of a local oscillator

What is the purpose of a step-start circuit in a high-voltage power supply?

To provide a dual-voltage output for reduced power applications
To compensate for variations of the incoming line voltage
To prevent arcing across the input power switch or relay contacts
To allow the filter capacitors to charge gradually

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

Equalize the voltage across each capacitor
Discharge the capacitors when voltage is removed
Provide a minimum load on the supply
All these choices are correct

Which of the following calculates power dissipated by a series linear voltage regulator?

Input voltage multiplied by input current
Input voltage divided by output current
Voltage difference from input to output multiplied by output current
Output voltage multiplied by output current

What is the dropout voltage of a linear voltage regulator?

Minimum input voltage for rated power dissipation
Maximum output voltage drop when the input voltage is varied over its specified range
Minimum input-to-output voltage required to maintain regulation
Maximum that the output voltage may decrease at rated load

What is the purpose of an inverter connected to a solar panel output?

Reduce AC ripple on the output
Maintain voltage with varying illumination levels
Prevent discharge when panel is not illuminated
Convert the panel's output from DC to AC

Why is a switching type power supply less expensive and lighter than an equivalent linear power supply?

The inverter design does not require an output filter circuit
The control circuitry uses less current, therefore smaller heat sinks are required
The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
It recovers power from the unused portion of the AC cycle, thus using fewer components

How is battery operating time calculated?

Average current divided by capacity in amp-hours
Average current divided by internal resistance
Capacity in amp-hours divided by average current
Internal resistance divided by average current

What type of circuit is shown in Figure E7-2?

Switching voltage regulator
Common emitter amplifier
Linear voltage regulator
Common base amplifier

What is the purpose of C2 in the circuit shown in Figure E7-2?

It bypasses rectifier output ripple around D1
It is a brute force filter for the output
To prevent self-oscillation
To provide fixed DC bias for Q1

What is the purpose of Q1 in the circuit shown in Figure E7-2?

It provides negative feedback to improve regulation
It provides a constant load for the voltage source
It controls the current to keep the output voltage constant
It provides regulation by switching or “chopping” the input DC voltage

Which of the following types of linear voltage regulator operates by loading the unregulated voltage source?

A constant current source
A series regulator
A shunt current source
A shunt regulator

Which of the following describes a three-terminal voltage regulator?

A series current source
A series regulator
A shunt regulator
A shunt current source

What device is used as a stable voltage reference?

A Zener diode
A digital-to-analog converter
An SCR
An analog-to-digital converter

How does a switchmode voltage regulator work?

By alternating the output between positive and negative voltages
By varying the duty cycle of pulses input to a filter
By varying the conductivity of a pass element
By switching between two Zener diode reference voltages

How does a linear electronic voltage regulator work?

It has a ramp voltage as its output
It eliminates the need for a pass transistor
The control element duty cycle is proportional to the line or load conditions
The conduction of a control element is varied to maintain a constant output voltage

Which of the following measures a filter's ability to reject signals in adjacent channels?

Passband ripple
Phase response
Shape factor
Noise factor

Which of the following filters is used in a 2-meter band repeater duplexer?

A crystal filter
A cavity filter
A DSP filter
An L-C filter

What is a crystal lattice filter?

A power supply filter made with interlaced quartz crystals
An audio filter made with four quartz crystals that resonate at 1 kHz intervals
A filter using lattice-shaped quartz crystals for high-Q performance
A filter for low-level signals made using quartz crystals

Which of the following is most frequently used as a band-pass or notch filter in VHF and UHF transceivers?

A Sallen-Key filter
A helical filter
A swinging choke filter
A finite impulse response filter

Which describes a Pi-L network?

A Phase Inverter Load network
A Pi-network with an additional output series inductor
A network with only three discrete parts
A matching network in which all components are isolated from ground

What are the characteristics of an elliptical filter?

Gradual passband rolloff with minimal stop-band ripple
Extremely flat response over its pass band with gradually rounded stop-band corners
Extremely sharp cutoff with one or more notches in the stop band
Gradual passband rolloff with extreme stop-band ripple

Which filter type has ripple in the passband and a sharp cutoff?

A Butterworth filter
An active LC filter
A passive op-amp filter
A Chebyshev filter

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

It introduces negative resistance to cancel the resistive part of impedance
It introduces transconductance to cancel the reactive part of impedance
It cancels the reactive part of the impedance and changes the resistive part to the desired value
Reactive currents are dissipated in matched resistances

What is the purpose of adding an inductor to a Pi-network to create a Pi-L-network?

Greater harmonic suppression
Higher efficiency
To eliminate one capacitor
Greater transformation range

What is the frequency response of a T-network with series capacitors and a shunt inductor?

Low-pass
High-pass
Band-pass
Notch

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between the input and output

What type of amplifier circuit is shown in Figure E7-1?

Common base
Common collector
Common emitter
Emitter follower

In Figure E7-1, what is the purpose of R3?

Fixed bias
Emitter bypass
Output load resistor
Self bias

In Figure E7-1, what is the purpose of R1 and R2?

Load resistors
Voltage divider bias
Self bias
Feedback

What is characteristic of an emitter follower (or common collector) amplifier?

Low input impedance and phase inversion from input to output
Differential inputs and single output
Acts as an OR circuit if one input is grounded
Input and output signals in-phase

Why are switching amplifiers more efficient than linear amplifiers?

Switching amplifiers operate at higher voltages
The switching device is at saturation or cutoff most of the time
Linear amplifiers have high gain resulting in higher harmonic content
Switching amplifiers use push-pull circuits

Which of the following is the likely result of using a Class C amplifier to amplify a single-sideband phone signal?

Reduced intermodulation products
Increased overall intelligibility
Reduced third-order intermodulation
Signal distortion and excessive bandwidth

What is a characteristic of a grounded-grid amplifier?

High power gain
Low input impedance
High electrostatic damage protection
Low bandwidth

What can be done to prevent unwanted oscillations in an RF power amplifier?

Tune the stage for minimum loading
Tune both the input and output for maximum power
Install parasitic suppressors and/or neutralize the stage
Use a phase inverter in the output filter

What is the operating point of a Class A common emitter amplifier?

Approximately halfway between saturation and cutoff
Approximately halfway between the emitter voltage and the base voltage
At a point where the bias resistor equals the load resistor
At a point where the load line intersects the zero bias current curve

What circuit is required at the output of an RF switching amplifier?

A filter to remove harmonic content
A high-pass filter to compensate for low gain at low frequencies
A matched load resistor to prevent damage by switching transients
A temperature compensating load resistor to improve linearity

What is a Class D amplifier?

An amplifier that uses switching technology to achieve high efficiency
A low power amplifier that uses a differential amplifier for improved linearity
An amplifier that uses drift-mode FETs for high efficiency
An amplifier biased to be relatively free from distortion

For what portion of the signal cycle does each active element in a push-pull, Class AB amplifier conduct?

More than 180 degrees but less than 360 degrees
Exactly 180 degrees
The entire cycle
Less than 180 degrees

What does "positive logic" mean in reference to logic devices?

The logic devices have high noise immunity
High voltage represents a 1, low voltage a 0
The logic circuit is in the “true” condition
1s and 0s are defined as different positive voltage levels

What is a truth table?

A list of inputs and corresponding outputs for an op-amp
A list of inputs and corresponding outputs for a digital device
A diagram showing logic states when the digital gate output is true
A table of logic symbols that indicate the logic states of an op-amp

What logical operation is performed by a two-input exclusive NOR gate?

It produces a 0 at its output only if all inputs are 0
It produces a 1 at its output only if all inputs are 1
It produces a 0 at its output if one and only one of its inputs is 1
It produces a 1 at its output if one and only one input is 1

What logical operation does an OR gate perform?

It produces a 1 at its output if any input is 1
It produces a 0 at its output if all inputs are 1
It produces a 0 at its output if some but not all inputs are 1
It produces a 1 at its output if all inputs are 0

What logical operation does a NAND gate perform?

It produces a 0 at its output only if all inputs are 0
It produces a 1 at its output only if all inputs are 1
It produces a 0 at its output if some but not all inputs are 1
It produces a 0 at its output only if all inputs are 1

What is a characteristic of a monostable multivibrator?

It switches temporarily to an alternate state for a set time
It produces a continuous square wave
It stores one bit of data
It maintains a constant output voltage, regardless of variations in the input voltage

Which of the following circuits continuously alternates between two states without an external clock signal?

Monostable multivibrator
J-K flip-flop
T flip-flop
Astable multivibrator

How many flip-flops are required to divide a signal frequency by 16?

4
6
8
16

Which of the following can divide the frequency of a pulse train by 2?

An XOR gate
A flip-flop
An OR gate
A multiplexer

What is the function of a decade counter?

It produces one output pulse for every 10 input pulses
It decodes a decimal number for display on a seven-segment LED display
It produces 10 output pulses for every input pulse
It decodes a binary number for display on a seven-segment LED display

Which circuit is bistable?

An AND gate
An OR gate
A flip-flop
A bipolar amplifier

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

0.5 volts
0.7 volts
1.1 volts
1.5 volts

What is the most common material used in power-generating photovoltaic cells?

Selenium
Silicon
Cadmium sulfide
Indium arsenide

What is the efficiency of a photovoltaic cell?

The output RF power divided by the input DC power
The output in lumens divided by the input power in watts
The open-circuit voltage divided by the short-circuit current under full illumination
The relative fraction of light that is converted to current

Why are optoisolators often used in conjunction with solid-state circuits that control 120 VAC circuits?

Optoisolators provide a low-impedance link between a control circuit and a power circuit
Optoisolators provide impedance matching between the control circuit and power circuit
Optoisolators provide an electrical isolation between a control circuit and the circuit being switched
Optoisolators eliminate the effects of reflected light in the control circuit

What is a solid-state relay?

A relay that uses transistors to drive the relay coil
A device that uses semiconductors to implement the functions of an electromechanical relay
A mechanical relay that latches in the on or off state each time it is pulsed
A semiconductor switch that uses a monostable multivibrator circuit

Which of these materials is most commonly used to create photoconductive devices?

Polyphenol acetate
Argon
Crystalline semiconductor
All these choices are correct

Which of the following describes an optical shaft encoder?

A device that detects rotation by interrupting a light source with a patterned wheel
A device that measures the strength of a beam of light using analog-to-digital conversion
An optical computing device in which light is coupled between devices by fiber optics
A device for generating RTTY signals by means of a rotating light source

What is the photovoltaic effect?

The conversion of voltage to current when exposed to light
The conversion of light to electrical energy
The effect that causes a photodiode to emit light when a voltage is applied
The effect that causes a phototransistor's beta to decrease when exposed to light

What is the most common configuration of an optoisolator or optocoupler?

A lens and a photomultiplier
A frequency-modulated helium-neon laser
An amplitude-modulated helium-neon laser
An LED and a phototransistor

What happens to photoconductive material when light shines on it?

Resistance decreases
Resistance increases
Reflectivity increases
Reflectivity decreases

What absorbs the energy from light falling on a photovoltaic cell?

Protons
Photons
Electrons
Holes

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Excessive dielectric loss
Epoxy coating is conductive above 300 MHz
Excessive lead length
Unsuitable for combining analog and digital signals

What is a characteristic of DIP packaging used for integrated circuits?

Extremely low stray capacitance (dielectrically isolated package)
Extremely high resistance between pins (doubly insulated package)
Two chips in each package (dual in package)
Two rows of connecting pins on opposite sides of package (dual in-line package)

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Smaller circuit area
Shorter circuit board traces
Components have less parasitic inductance and capacitance
All these choices are correct

Which of the following component package types have the least parasitic effects at frequencies above the HF range?

TO-220
Axial lead
Radial lead
Surface mount

How is power supplied to the most common type of MMIC?

Through a capacitor and RF choke connected to the amplifier input lead
MMICs require no operating bias
Through a resistor and/or RF choke connected to the amplifier output lead
Directly to the bias voltage (Vcc) lead

What type of transmission line is often used for connections to MMICs?

Miniature coax
Circular waveguide
Parallel wire
Microstrip

What characteristics of MMICs make them a popular choice for VHF through microwave circuits?

The ability to retrieve information from a single signal, even in the presence of other strong signals
Extremely high Q factor and high stability over a wide temperature range
Nearly infinite gain, very high input impedance, and very low output impedance
Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

0.5 dB
-10 dB
44 dBm
-20 dBm

Which is the most common input and output impedance of MMICs?

50 ohms
300 ohms
450 ohms
75 ohms

Which of the following materials supports the highest frequency of operation when used in MMICs?

Silicon
Silicon nitride
Silicon dioxide
Gallium nitride

Which of the following device packages is a through-hole type?

DIP
PLCC
BGA
SOT

Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies?

Higher noise figures
Higher electron mobility
Lower junction voltage drop
Lower transconductance

What causes inductor saturation?

Operation at too high a frequency
Selecting a core with low permeability
Operation at excessive magnetic flux
Selecting a core with excessive permittivity

Which type of core material decreases inductance when inserted into a coil?

Ceramic
Brass
Ferrite
Aluminum

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Toroidal cores confine most of the magnetic field within the core material
Toroidal cores make it easier to couple the magnetic energy into other components
Toroidal cores exhibit greater hysteresis
Toroidal cores have lower Q characteristics

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Electrolytic capacitors
Butterworth filters
Ferrite beads
Steel-core toroids

Which of the following materials has the highest temperature stability of its magnetic characteristics?

Brass
Powdered iron
Ferrite
Aluminum

What is the current that flows in the primary winding of a transformer when there is no load on the secondary winding?

Stabilizing current
Direct current
Excitation current
Magnetizing current

What core material property determines the inductance of an inductor?

Permittivity
Resistance
Reactivity
Permeability

How do ferrite and powdered iron compare for use in an inductor core?

Ferrite cores generally have lower initial permeability
Ferrite cores generally have better temperature stability
Ferrite cores generally require fewer turns to produce a given inductance value
Ferrite cores are easier to use with surface-mount technology

Why are cores of inductors and transformers sometimes constructed of thin layers?

To simplify assembly during manufacturing
To reduce power loss from eddy currents in the core
To increase the cutoff frequency by reducing capacitance
To save cost by reducing the amount of magnetic material

Which of the following is an aspect of the piezoelectric effect?

Mechanical deformation of material due to the application of a voltage
Mechanical deformation of material due to the application of a magnetic field
Generation of electrical energy in the presence of light
Increased conductivity in the presence of light

What is the equivalent circuit of a quartz crystal?

Series RLC in parallel with a shunt C representing electrode and stray capacitance
Parallel RLC, where C is the parallel combination of resonance capacitance of the crystal and electrode and stray capacitance
Series RLC, where C is the parallel combination of resonance capacitance of the crystal and electrode and stray capacitance
Parallel RLC, where C is the series combination of resonance capacitance of the crystal and electrode and stray capacitance

What is piezoelectricity?

The ability of materials to generate electromagnetic waves of a certain frequency when voltage is applied
A characteristic of materials that have an index of refraction which depends on the polarization of the electromagnetic wave passing through it
A characteristic of materials that generate a voltage when stressed and that flex when a voltage is applied
The ability of materials to generate voltage when an electromagnetic wave of a certain frequency is applied

In Figure E6-3, which is the schematic symbol for the NOT operation (inversion)?

2
4
5
6

In Figure E6-3, which is the schematic symbol for a NOR gate?

1
2
3
4

What is used to design the configuration of a field-programmable gate array (FPGA)?

Karnaugh maps
Hardware description language (HDL)
An auto-router
Machine and assembly language

In Figure E6-3, which is the schematic symbol for a NAND gate?

1
2
3
4

What best describes a pull-up or pull-down resistor?

A resistor in a keying circuit used to reduce key clicks
A resistor connected to the positive or negative supply used to establish a voltage when an input or output is an open circuit
A resistor that ensures that an oscillator frequency does not drift
A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Large bypass capacitance is inherent
The input switching threshold is about twice the power supply voltage
The input switching threshold is about half the power supply voltage
Bandwidth is very limited

Which of the following digital logic families has the lowest power consumption?

Schottky TTL
ECL
NMOS
CMOS

Which of the following is an advantage of BiCMOS logic?

Its simplicity results in much less expensive devices than standard CMOS
It is immune to electrostatic damage
It has the high input impedance of CMOS and the low output impedance of bipolar transistors
All these choices are correct

What is tri-state logic?

Logic devices with 0, 1, and high-impedance output states
Logic devices that utilize ternary math
Logic with three output impedances which can be selected to better match the load impedance
A counter with eight states

What happens when the level of a comparator's input signal crosses the threshold voltage?

The IC input can be damaged
The comparator changes its output state
The reference level appears at the output
The feedback loop becomes unstable

What is the function of hysteresis in a comparator?

To prevent input noise from causing unstable output signals
To allow the comparator to be used with AC input signals
To cause the output to continually change states
To increase the sensitivity

What is used to control the attenuation of RF signals by a PIN diode?

Forward DC bias current
A variable RF reference voltage
Reverse voltage larger than the RF signal
Capacitance of an RF coupling capacitor

In Figure E6-2, which is the schematic symbol for a Schottky diode?

1
6
2
3

What is a common use for point-contact diodes?

As a constant current source
As a constant voltage source
As an RF detector
As a high-voltage rectifier

Which of the following is a Schottky barrier diode?

Metal-semiconductor junction
Electrolytic rectifier
PIN junction
Thermionic emission diode

What causes a junction diode to fail from excessive current?

Excessive inverse voltage
Excessive junction temperature
Insufficient forward voltage
Charge carrier depletion

Which of the following is a common use of a Schottky diode?

In oscillator circuits as the negative resistance element
As a variable capacitance in an automatic frequency control circuit
In power supplies as a constant voltage reference
As a VHF/UHF mixer or detector

What characteristic of a PIN diode makes it useful as an RF switch?

Extremely high reverse breakdown voltage
Ability to dissipate large amounts of power
Reverse bias controls its forward voltage drop
Low junction capacitance

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Varactor diode
Tunnel diode
Silicon-controlled rectifier
Zener diode

What property of an LED's semiconductor material determines its forward voltage drop?

Intrinsic resistance
Band gap
Junction capacitance
Junction depth

Which characteristic of a Schottky diode makes it a better choice than a silicon junction diode for use as a power supply rectifier?

Much higher reverse voltage breakdown
More constant reverse avalanche voltage
Longer carrier retention time
Lower forward voltage drop

What is the most useful characteristic of a Zener diode?

A constant current drop under conditions of varying voltage
A constant voltage drop under conditions of varying current
A negative resistance region
An internal capacitance that varies with the applied voltage

What is the purpose of connecting Zener diodes between a MOSFET gate and its source or drain?

To provide a voltage reference for the correct amount of reverse-bias gate voltage
To protect the substrate from excessive voltages
To keep the gate voltage within specifications and prevent the device from overheating
To protect the gate from static damage

In Figure E6-1, which is the schematic symbol for a P-channel junction FET?

1
2
3
6

In Figure E6-1, which is the schematic symbol for an N-channel dual-gate MOSFET?

2
4
5
6

What is a depletion-mode field-effect transistor (FET)?

An FET that exhibits a current flow between source and drain when no gate voltage is applied
An FET that has no current flow between source and drain when no gate voltage is applied
An FET that exhibits very high electron mobility due to a lack of holes in the N-type material
An FET for which holes are the majority carriers

What is the term for the frequency at which the grounded-base current gain of a bipolar junction transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Corner frequency
Alpha rejection frequency
Beta cutoff frequency
Alpha cutoff frequency

Which of the following indicates that a silicon NPN junction transistor is biased on?

Base-to-emitter resistance of approximately 6 ohms to 7 ohms
Base-to-emitter resistance of approximately 0.6 ohms to 0.7 ohms
Base-to-emitter voltage of approximately 6 volts to 7 volts
Base-to-emitter voltage of approximately 0.6 volts to 0.7 volts

What is the beta of a bipolar junction transistor?

The frequency at which the current gain is reduced to 0.707
The change in collector current with respect to base current
The breakdown voltage of the base-to-collector junction
The switching speed

How does DC input impedance at the gate of a field-effect transistor (FET) compare with that of a bipolar transistor?

They are both low impedance
An FET has lower input impedance
An FET has higher input impedance
They are both high impedance

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Insulator impurity
N-type impurity
Acceptor impurity
Donor impurity

Why does a PN-junction diode not conduct current when reverse biased?

Only P-type semiconductor material can conduct current
Only N-type semiconductor material can conduct current
Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator

Which of the following semiconductor materials contains excess free electrons?

N-type
P-type
Bipolar
Insulated gate

In what application is gallium arsenide used as a semiconductor material?

In high-current rectifier circuits
In high-power audio circuits
In microwave circuits
In very low-frequency RF circuits

What is reactive power?

Power consumed in circuit Q
Power consumed by an inductor's wire resistance
The power consumed in inductors and capacitors
Wattless, nonproductive power

How much real power is consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

70.7 watts
100 watts
141.4 watts
200 watts

As a conductor's diameter increases, what is the effect on its electrical length?

Thickness has no effect on electrical length
It varies randomly
It decreases
It increases

What happens to reactive power in ideal inductors and capacitors?

It is dissipated as heat in the circuit
Energy is stored in magnetic or electric fields, but power is not dissipated
It is canceled by Coulomb forces in the capacitor and inductor
It is dissipated in the formation of inductive and capacitive fields

What is the primary cause of loss in film capacitors at RF?

Inductance
Dielectric loss
Self-discharge
Skin effect

What combines to create the self-resonance of a component?

The component's resistance and reactance
The component's nominal and parasitic reactance
The component's inductance and capacitance
The component's electrical length and impedance

What parasitic characteristic creates an inductor's self-resonance?

Skin effect
Dielectric loss
Coupling
Inter-turn capacitance

What parasitic characteristic causes electrolytic capacitors to be unsuitable for use at RF?

Skin effect
Shunt capacitance
Inductance
Dielectric leakage

Why are short connections used at microwave frequencies?

To increase neutralizing resistance
To reduce phase shift along the connection
To increase compensating capacitance
To reduce noise figure

What is the phase relationship between current and voltage for reactive power?

They are out of phase
They are in phase
They are 90 degrees out of phase
They are 45 degrees out of phase

Why is it important to keep lead lengths short for components used in circuits for VHF and above?

To increase the thermal time constant
To minimize inductive reactance
To maintain component lifetime
All these choices are correct

What is the result of conductor skin effect?

Resistance increases as frequency increases because RF current flows closer to the surface
Resistance decreases as frequency increases because electron mobility increases
Resistance increases as temperature increases because of the change in thermal coefficient
Resistance decreases as temperature increases because of the change in thermal coefficient

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Point 1
Point 3
Point 7
Point 8

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

Point 1
Point 3
Point 7
Point 8

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

Point 2
Point 4
Point 5
Point 6

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

The X axis represents the resistive component, and the Y axis represents the reactive component
The X axis represents the reactive component, and the Y axis represents the resistive component
The X axis represents the phase angle, and the Y axis represents the magnitude
The X axis represents the magnitude, and the Y axis represents the phase angle

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive, and/or capacitive reactance?

Maidenhead grid
Faraday grid
Elliptical coordinates
Polar coordinates

Where is the impedance of a pure resistance plotted on rectangular coordinates?

On the vertical axis
On a line through the origin, slanted at 45 degrees
On a horizontal line, offset vertically above the horizontal axis
On the horizontal axis

What does the impedance 50 - j25 ohms represent?

50 ohms resistance in series with 25 ohms inductive reactance
50 ohms resistance in series with 25 ohms capacitive reactance
25 ohms resistance in series with 50 ohms inductive reactance
25 ohms resistance in series with 50 ohms capacitive reactance

What kind of diagram is used to show the phase relationship between impedances at a given frequency?

Venn diagram
Near field diagram
Phasor diagram
Far field diagram

What type of Y-axis scale is most often used for graphs of circuit frequency response?

Linear
Scatter
Random
Logarithmic

Which of the following represents a pure inductive reactance in polar coordinates?

A positive 45 degree phase angle
A negative 45 degree phase angle
A positive 90 degree phase angle
A negative 90 degree phase angle

How are impedances described in polar coordinates?

By X and R values
By real and imaginary parts
By magnitude and phase angle
By Y and G values

Which of the following represents pure capacitive reactance of 100 ohms in rectangular notation?

0 - j100
0 + j100
100 - j0
100 + j0

What is admittance?

The inverse of impedance
The term for the gain of a field effect transistor
The inverse of reactance
The term for the on-impedance of a field effect transistor

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 75 ohms?

27 degrees with the voltage lagging the current
27 degrees with the voltage leading the current
63 degrees with the voltage lagging the current
63 degrees with the voltage leading the current

What is the relationship between the AC current through an inductor and the voltage across an inductor?

Voltage leads current by 90 degrees
Current leads voltage by 90 degrees
Voltage and current are 180 degrees out of phase
Voltage and current are in phase

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

Voltage and current are in phase
Voltage and current are 180 degrees out of phase
Voltage leads current by 90 degrees
Current leads voltage by 90 degrees

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 300 ohms, R is 100 ohms, and XL is 100 ohms?

63 degrees with the voltage lagging the current
63 degrees with the voltage leading the current
27 degrees with the voltage leading the current
27 degrees with the voltage lagging the current

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

68.2 degrees with the voltage leading the current
14.0 degrees with the voltage leading the current
14.0 degrees with the voltage lagging the current
68.2 degrees with the voltage lagging the current

What is susceptance?

The magnetic impedance of a circuit
The ratio of magnetic field to electric field
The imaginary part of admittance
A measure of the efficiency of a transformer

What is the effect on the magnitude of pure reactance when it is converted to susceptance?

It is unchanged
The sign is reversed
It is shifted by 90 degrees
It is replaced by its reciprocal

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

55 seconds
110 seconds
440 seconds
220 seconds

How is impedance in polar form converted to an equivalent admittance?

Take the reciprocal of the angle and change the sign of the magnitude
Take the reciprocal of the magnitude and change the sign of the angle
Take the square root of the magnitude and add 180 degrees to the angle
Square the magnitude and subtract 90 degrees from the angle

What letter is commonly used to represent susceptance?

G
X
Y
B

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

An exponential rate of one
One time constant
One exponential period
A time factor of one

What is an effect of increasing Q in a series resonant circuit?

Fewer components are needed for the same performance
Parasitic effects are minimized
Internal voltages increase
Phase shift can become uncontrolled

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

436.6 kHz
218.3 kHz
31.4 kHz
15.7 kHz

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

157.8 Hz
315.6 Hz
47.3 kHz
23.67 kHz

What is the resonant frequency of an RLC circuit if R is 33 ohms, L is 50 microhenries, and C is 10 picofarads?

7.12 MHz
23.5 kHz
7.12 kHz
23.5 MHz

How is the Q of an RLC parallel resonant circuit calculated?

Reactance of either the inductance or capacitance divided by the resistance
Reactance of either the inductance or capacitance multiplied by the resistance
Resistance divided by the reactance of either the inductance or capacitance
Reactance of the inductance multiplied by the reactance of the capacitance

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

The voltage leads the current by 90 degrees
The current leads the voltage by 90 degrees
The voltage and current are in phase
The voltage and current are 180 degrees out of phase

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Minimum
Maximum
R/L
L/R

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

It is at a minimum
It is at a maximum
It equals 1 divided by the quantity 2 times pi, times the square root of (inductance L multiplied by capacitance C)
It equals 2 times pi, times the square root of (inductance L multiplied by capacitance C)

What is the result of increasing the Q of an impedance-matching circuit?

Matching bandwidth is decreased
Matching bandwidth is increased
Losses increase
Harmonics increase

What is the magnitude of the impedance of a parallel RLC circuit at resonance?

Approximately equal to circuit resistance
Approximately equal to inductive reactance
Low compared to the circuit resistance
High compared to the circuit resistance

What is the magnitude of the impedance of a series RLC circuit at resonance?

High, compared to the circuit resistance
Approximately equal to capacitive reactance
Approximately equal to inductive reactance
Approximately equal to circuit resistance

What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries, and C is 40 picofarads?

44.72 MHz
22.36 MHz
3.56 MHz
1.78 MHz

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

Resonance
Capacitance
Low quality factor (Q)
Resistance

What is the purpose of a single point ground panel?

Remove AC power in case of a short-circuit
Prevent common-mode transients in multi-wire systems
Eliminate air gaps between protected and non-protected circuits
Ensure all lightning protectors activate at the same time

Where should a station AC surge protector be installed?

At the AC service panel
At an AC outlet
On the single point ground panel
On a ground rod outside the station

What causes interference received as a series of carriers at regular intervals across a wide frequency range?

Switch-mode power supplies
Radar transmitters
Wireless security camera transmitters
Electric fences

What could be the cause of local AM broadcast band signals combining to generate spurious signals on the MF or HF bands?

One or more of the broadcast stations is transmitting an over-modulated signal
Nearby corroded metal connections are mixing and reradiating the broadcast signals
You are receiving skywave signals from a distant station
Your station receiver IF amplifier stage is overloaded

Which of the following can create intermittent loud roaring or buzzing AC line interference?

Arcing contacts in a thermostatically controlled device
A defective doorbell or doorbell transformer inside a nearby residence
A malfunctioning illuminated advertising display
All these choices are correct

What undesirable effect can occur when using a noise blanker?

Received audio in the speech range might have an echo effect
The audio frequency bandwidth of the received signal might be compressed
Strong signals may be distorted and appear to cause spurious emissions
FM signals can no longer be demodulated

What current flows equally on all conductors of an unshielded multiconductor cable?

Differential-mode current
Common-mode current
Reactive current only
Magnetically-coupled current only

Which of the following can cause shielded cables to radiate or receive interference?

Low inductance ground connections at both ends of the shield
Common-mode currents on the shield and conductors
Use of braided shielding material
Tying all ground connections to a common point resulting in differential-mode currents in the shield

What type of electrical interference can be caused by computer network equipment?

A loud AC hum in the audio output of your station's receiver
A clicking noise at intervals of a few seconds
The appearance of unstable modulated or unmodulated signals at specific frequencies
A whining-type noise that continually pulses off and on

What is used to suppress radio frequency interference from a line-driven AC motor?

A high-pass filter in series with the motor's power leads
A brute-force AC-line filter in series with the motor's power leads
A bypass capacitor in series with the motor's field winding
A bypass choke in parallel with the motor's field winding

How can conducted noise from an automobile battery charging system be suppressed?

By installing filter capacitors in series with the alternator leads
By installing a noise suppression resistor and a blocking capacitor at the battery
By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the antenna feed line
By installing ferrite chokes on the charging system leads

Which of the following types of noise are removed by a noise blanker?

Broadband white noise
Impulse noise
Hum and buzz
All these choices are correct

Which of the following types of noise can often be reduced by a digital noise reduction?

Broadband white noise
Ignition noise
Power line noise
All these choices are correct

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Removal of the CW signal as well as the interfering carrier
Any nearby signal passing through the DSP system will overwhelm the desired signal
Excessive ringing
All these choices are correct

What power level does a receiver minimum discernible signal of -100 dBm represent?

100 microwatts
0.1 microwatt
0.001 microwatts
0.1 picowatts

What is the received signal level with a transmit power of 100 W (+40 dBm), a transmit antenna gain of 6 dBi, a receive antenna gain of 3 dBi, and a path loss of 100 dB?

-51 dBm
-54 dBm
-57 dBm
-60 dBm

What is the link margin in a system with a transmit power level of 100 W (+40 dBm), a system antenna gain of 10 dBi, a cable loss of 3 dB, a path loss of 136 dB, a receiver minimum discernable signal of -103 dBm, and a required signal-to-noise ratio of 6 dB?

-8dB
-14dB
+8dB
+14dB

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

Odd-order products of two signals in the band being received are also likely to be within the band
Odd-order products are more likely to overload the IF filters
Odd-order products are an indication of poor image rejection
Odd-order intermodulation produces three products for every input signal within the band of interest

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Signals less than 40 dBm will not generate audible third-order intermodulation products
The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
A pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals
A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal

What is the purpose of the preselector in a communications receiver?

To store frequencies that are often used
To provide broadband attenuation before the first RF stage to prevent intermodulation
To increase the rejection of signals outside the band being received
To allow selection of the optimum RF amplifier device

What causes intermodulation in an electronic circuit?

Negative feedback
Lack of neutralization
Nonlinear circuits or devices
Positive feedback

Which of the following reduces the likelihood of receiver desensitization?

Insert attenuation before the first RF stage
Raise the receiver's IF frequency
Increase the receiver's front-end gain
Switch from fast AGC to slow AGC

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Reciprocal mixing
Quieting
Desensitization
Cross modulation interference

What transmitter frequencies would create an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

146.34 MHz and 146.61 MHz
146.88 MHz and 146.34 MHz
146.10 MHz and 147.30 MHz
146.30 MHz and 146.90 MHz

Which of the following is used to reduce or eliminate intermodulation interference in a repeater caused by a nearby transmitter?

A band-pass filter in the feed line between the transmitter and receiver
A properly terminated circulator at the output of the repeater's transmitter
Utilizing a Class C final amplifier
Utilizing a Class D final amplifier

What creates intermodulation interference between two repeaters in close proximity?

The output signals cause feedback in the final amplifier of one or both transmitters
The output signals mix in the final amplifier of one or both transmitters
The input frequencies are harmonically related
The output frequencies are harmonically related

Which of the following describes problems caused by poor dynamic range in a receiver?

Spurious signals caused by cross modulation and desensitization from strong adjacent signals
Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
Poor weak signal reception caused by insufficient local oscillator injection
Oscillator instability and severe audio distortion of all but the strongest received signals

What is meant by the blocking dynamic range of a receiver?

The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
The difference in dB between the noise floor and the third-order intercept point
The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor

What is the purpose of the receiver IF Shift control?

To permit listening on a different frequency from the transmitting frequency
To change frequency rapidly
To reduce interference from stations transmitting on adjacent frequencies
To tune in stations slightly off frequency without changing the transmit frequency

What is reciprocal mixing?

Two out-of-band signals mixing to generate an in-band spurious signal
In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
Two digital signals combining from alternate time slots
Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals

How does a narrow-band roofing filter affect receiver performance?

It improves sensitivity by reducing front-end noise
It improves intelligibility by using low Q circuitry to reduce ringing
It improves blocking dynamic range by attenuating strong signals near the receive frequency
All these choices are correct

Why does input attenuation reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?

The attenuator has a low-pass filter to increase the strength of lower frequency signals
The attenuator has a noise filter to suppress interference
Signals are attenuated separately from the noise
Atmospheric noise is generally greater than internally generated noise even after attenuation

What is an advantage of having a variety of receiver bandwidths from which to select?

The noise figure of the RF amplifier can be adjusted to match the modulation type, thus increasing receiver sensitivity
Receiver power consumption can be reduced when wider bandwidth is not required
Receive bandwidth can be set to match the modulation bandwidth, maximizing signal-to-noise ratio and minimizing interference
Multiple frequencies can be received simultaneously if desired

Which of the following choices is a good reason for selecting a high IF for a superheterodyne HF or VHF communications receiver?

Fewer components in the receiver
Reduced drift
Easier for front-end circuitry to eliminate image responses
Improved receiver noise figure

An SDR receiver is overloaded when input signals exceed what level?

One-half of the maximum sample rate
One-half of the maximum sampling buffer size
The maximum count value of the analog-to-digital converter
The reference voltage of the analog-to-digital converter

What does the MDS of a receiver represent?

The meter display sensitivity
The minimum discernible signal
The modulation distortion specification
The maximum detectable spectrum

How much does increasing a receiver's bandwidth from 50 Hz to 1,000 Hz increase the receiver's noise floor?

3 dB
5 dB
10 dB
13 dB

What does a receiver noise floor of -174 dBm represent?

The receiver noise is 6 dB above the theoretical minimum
The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature
The noise figure of a 1 Hz bandwidth receiver
The receiver noise is 3 dB above theoretical minimum

What is the noise figure of a receiver?

The ratio of atmospheric noise to phase noise
The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
The ratio in dB of the noise generated in the receiver to atmospheric noise
The ratio in dB of the noise generated by the receiver to the theoretical minimum noise

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Desensitization
Cross-modulation interference
Capture effect
Frequency discrimination

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

A front-end filter or preselector
A narrow IF filter
A notch filter
A properly adjusted product detector

What is an effect of excessive phase noise in an SDR receiver's master clock oscillator?

It limits the receiver's ability to receive strong signals
It can affect the receiver's frequency calibration
It decreases the receiver's third-order intercept point
It can combine with strong signals on nearby frequencies to generate interference

Which of the following can be measured with a vector network analyzer?

Input impedance
Output impedance
Reflection coefficient
All these choices are correct

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer

Which of the following can be measured by a two-port vector network analyzer?

Phase noise
Filter frequency response
Pulse rise time
Forward power

Which of the following can be used to determine the Q of a series-tuned circuit?

The ratio of inductive reactance to capacitive reactance
The frequency shift
The bandwidth of the circuit's frequency response
The resonant frequency of the circuit

What do the subscripts of S parameters represent?

The port or ports at which measurements are made
The relative time between measurements
Relative quality of the data
Frequency order of the measurements

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

100 watts
125 watts
112.5 watts
75 watts

What three test loads are used to calibrate an RF vector network analyzer?

50 ohms, 75 ohms, and 90 ohms
Short circuit, open circuit, and 50 ohms
Short circuit, open circuit, and resonant circuit
50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

S11
S12
S21
S22

Which S parameter is equivalent to forward gain?

S11
S12
S21
S22

What is the significance of voltmeter sensitivity expressed in ohms per volt?

The full scale reading of the voltmeter multiplied by its ohms per volt rating is the input impedance of the voltmeter
The reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
The reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
The full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed

Which of the following factors most affects the accuracy of a frequency counter?

Input attenuator accuracy
Time base accuracy
Decade divider accuracy
Temperature coefficient of the logic

Which of the following can be measured with an antenna analyzer?

Velocity factor
Cable length
Resonant frequency of a tuned circuit
All these choices are correct

Which trigger mode is most effective when using an oscilloscope to measure a linear power supply's output ripple?

Single-shot
Edge
Level
Line

Which of the following is good practice when using an oscilloscope probe?

Minimize the length of the probe's ground connection
Never use a high-impedance probe to measure a low-impedance circuit
Never use a DC-coupled probe to measure an AC circuit
All these choices are correct

Which of the following is used to measure SWR?

Directional wattmeter
Vector network analyzer
Antenna analyzer
All these choices are correct

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge?

Antenna analyzers automatically tune your antenna for resonance
Antenna analyzers compute SWR and impedance automatically
Antenna analyzers display a time-varying representation of the modulation envelope
All these choices are correct

What is the effect of aliasing on a digital oscilloscope when displaying a waveform?

A false, jittery low-frequency version of the waveform is displayed
The waveform DC offset will be inaccurate
Calibration of the vertical scale is no longer valid
Excessive blanking occurs, which prevents display of the waveform

What is the purpose of using a prescaler with a frequency counter?

Amplify low-level signals for more accurate counting
Multiply a higher frequency signal so a low-frequency counter can display the operating frequency
Prevent oscillation in a low-frequency counter circuit
Reduce the signal frequency to within the counter's operating range

How is compensation of an oscilloscope probe performed?

A square wave is displayed, and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
A high frequency sine wave is displayed, and the probe is adjusted for maximum amplitude
A frequency standard is displayed, and the probe is adjusted until the deflection time is accurate
A DC voltage standard is displayed, and the probe is adjusted until the displayed voltage is accurate

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Differential resolver
Spectrum analyzer
Logic analyzer
Network analyzer

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Signal amplitude and time
Signal amplitude and frequency
SWR and frequency
SWR and time

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Sampling rate of the analog-to-digital converter
Analog-to-digital converter reference frequency
Q of the circuit
All these choices are correct

Which of the following is indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

A temperature inversion has occurred
A coronal mass ejection impact or a solar flare has occurred
Transequatorial propagation on 6 meters is likely
Long-path propagation on the higher HF bands is likely

What does VOACAP software model?

AC voltage and impedance
VHF radio propagation
HF propagation
AC current and impedance

What does the 304A solar parameter measure?

The ratio of X-ray flux to radio flux, correlated to sunspot number
UV emissions at 304 angstroms, correlated to the solar flux index
The solar wind velocity at an angle of 304 degrees from the solar equator, correlated to geomagnetic storms
The solar emission at 304 GHz, correlated to X-ray flare levels

What type of data is reported by amateur radio propagation reporting networks?

Solar flux
Electric field intensity
Magnetic declination
Digital-mode and CW signals

Which of the following is the space-weather term for an extreme geomagnetic storm?

B9
X5
M9
G5

Which of the following indicates the greatest solar flare intensity?

Class A
Class Z
Class M
Class X

How does the VHF/UHF radio horizon compare to the geographic horizon?

It is approximately 15 percent farther
It is approximately 20 percent nearer
It is approximately 50 percent farther
They are approximately the same

What orientation of Bz (B sub z) increases the likelihood that charged particles from the Sun will cause disturbed conditions?

Southward
Northward
Eastward
Westward

What does the value of Bz (B sub z) represent?

Geomagnetic field stability
Critical frequency for vertical transmissions
North-south strength of the interplanetary magnetic field
Duration of long-delayed echoes

Which of the following signal paths is most likely to experience high levels of absorption when the A-index or K-index is elevated?

Transequatorial
Through the auroral oval
Sporadic-E
NVIS

What is indicated by a rising A-index or K-index?

Increasing disturbance of the geomagnetic field
Decreasing disturbance of the geomagnetic field
Higher levels of solar UV radiation
An increase in the critical frequency

What is the cause of short-term radio blackouts?

Coronal mass ejections
Sunspots on the solar equator
North-oriented interplanetary magnetic field
Solar flares

What type of polarization is supported by ground-wave propagation?

Vertical
Horizontal
Circular
Elliptical

What is chordal-hop propagation?

Propagation away from the great circle bearing between stations
Successive ionospheric refractions without an intermediate reflection from the ground
Propagation across the geomagnetic equator
Signals reflected back toward the transmitting station

At what time of day is sporadic-E propagation most likely to occur?

Between midnight and sunrise
Between sunset and midnight
Between sunset and sunrise
Between sunrise and sunset

What is the effect of chordal-hop propagation?

The signal experiences less loss compared to multi-hop propagation, which uses Earth as a reflector
The MUF for chordal-hop propagation is much lower than for normal skip propagation
Atmospheric noise is reduced in the direction of chordal-hop propagation
Signals travel faster along ionospheric chords

At what time of year is sporadic-E propagation most likely to occur?

Around the solstices, especially the summer solstice
Around the solstices, especially the winter solstice
Around the equinoxes, especially the spring equinox
Around the equinoxes, especially the fall equinox

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

It stays the same
It increases
It decreases
It peaks at roughly 8 MHz

What effect does lowering a signal's transmitted elevation angle have on ionospheric HF skip propagation?

Faraday rotation becomes stronger
The MUF decreases
The distance covered by each hop increases
The critical frequency increases

On which of the following amateur bands is long-path propagation most frequent?

160 meters and 80 meters
40 meters and 20 meters
10 meters and 6 meters
6 meters and 2 meters

Which of the following paths is most likely to support long-distance propagation on 160 meters?

A path entirely in sunlight
Paths at high latitudes
A direct north-south path
A path entirely in darkness

What are "extraordinary" and "ordinary" waves?

Extraordinary waves exhibit rare long-skip propagation, compared to ordinary waves, which travel shorter distances
Independently propagating, elliptically polarized waves created in the ionosphere
Long-path and short-path waves
Refracted rays and reflected waves

At what time of day is transequatorial propagation most likely to occur?

Morning
Noon
Afternoon or early evening
Late at night

What is the approximate maximum range for signals using transequatorial propagation?

1,000 miles
2,500 miles
5,000 miles
7,500 miles

Where is transequatorial propagation (TEP) most likely to occur?

Between points separated by 2,000 miles to 3,000 miles over a path perpendicular to the geomagnetic equator
Between points located 1,500 miles to 2,000 miles apart on the geomagnetic equator
Between points located at each other's antipode
Through the region where the terminator crosses the geographic equator

What are circularly polarized electromagnetic waves?

Waves with an electric field bent into a circular shape
Waves with rotating electric and magnetic fields
Waves that circle Earth
Waves produced by a loop antenna

Which of these emission modes is best for auroral propagation?

CW
SSB
FM
RTTY

What is most likely to result in auroral propagation?

Meteor showers
Quiet geomagnetic conditions
Severe geomagnetic storms
Extreme low-pressure areas in polar regions

What is a typical range for tropospheric duct propagation of microwave signals?

10 miles to 50 miles
100 miles to 300 miles
1,200 miles
2,500 miles

What determines the speed of electromagnetic waves through a medium?

Resistance and reactance
Evanescence
Birefringence
The index of refraction

Which of the following frequency ranges is most suited for meteor-scatter communications?

1.8 MHz - 1.9 MHz
10 MHz - 14 MHz
28 MHz - 148 MHz
220 MHz - 450 MHz

When a meteor strikes the Earth's atmosphere, a linear ionized region is formed at what region of the ionosphere?

The E region
The F1 region
The F2 region
The D region

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Mountain ranges
Stratocumulus clouds
Large bodies of water
Nimbus clouds

What should be done to continue a long-distance contact when the MUF for that path decreases due to darkness?

Switch to a higher frequency HF band
Switch to a lower frequency HF band
Change to an antenna with a higher takeoff angle
Change to an antenna with greater beam width

How are the component fields of an electromagnetic wave oriented?

They are parallel
They are tangential
They are at right angles
They are 90 degrees out of phase

In what direction does an electromagnetic wave travel?

It depends on the phase angle of the magnetic field
It travels parallel to the electric and magnetic fields
It depends on the phase angle of the electric field
It travels at a right angle to the electric and magnetic fields

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

When the Moon is at perigee
When the Moon is full
When the Moon is at apogee
When the MUF is above 30 MHz

What characterizes libration fading of an EME signal?

A slow change in the pitch of the CW signal
A fluttery, irregular fading
A gradual loss of signal as the sun rises
The returning echo is several hertz lower in frequency than the transmitted signal

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

2,000 miles, if the moon is at perigee
2,000 miles, if the moon is at apogee
5,000 miles, if the moon is at perigee
12,000 miles, if the moon is “visible” by both stations

Which of these digital modes has the highest data throughput under clear communication conditions?

MFSK16
170 Hz shift, 45 baud RTTY
FT8
PACTOR IV

How do ALE stations establish contact?

ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
ALE radios monitor an internet site for the frequency they are being paged on
ALE radios send a constant tone code to establish a frequency for future use
ALE radios activate when they hear their signal echoed by back scatter

What is the difference between direct FSK and audio FSK?

Direct FSK modulates the transmitter VFO
Direct FSK occupies less bandwidth
Direct FSK can transmit higher baud rates
All these choices are correct

Which of these digital modes has the narrowest bandwidth?

MFSK16
170 Hz shift, 45-baud RTTY
FT8
PACTOR IV

Which of the following HF digital modes uses variable-length character coding?

RTTY
PACTOR
MT63
PSK31

Which of the following HF digital modes can be used to transfer binary files?

PSK31
PACTOR
RTTY
AMTOR

How does Q65 differ from JT65?

Keyboard-to keyboard operation is supported
Quadrature modulation is used
Multiple receive cycles are averaged
All these choices are correct

What is the length of an FT8 transmission cycle?

It varies with the amount of data
8 seconds
15 seconds
30 seconds

Which of these digital modes does not support keyboard-to-keyboard operation?

WSPR
RTTY
PSK31
MFSK16

Which of the following is characteristic of the FST4 mode?

Four-tone Gaussian frequency shift keying
Variable transmit/receive periods
Seven different tone spacings
All these choices are correct

To what does the "4" in FT4 refer?

Multiples of 4 bits of user information
Four-tone continuous-phase frequency shift keying
Four transmit/receive cycles per minute
All these choices are correct

Which of the following synchronizes WSJT-X digital mode transmit/receive timing?

Alignment of frequency shifts
Synchronization of computer clocks
Sync-field transmission
Sync-pulse timing

Which of the following types of modulation is used for data emissions below 30 MHz?

DTMF tones modulating an FM signal
FSK
Pulse modulation
Spread spectrum

How do APRS stations relay data?

By packet ACK/NAK relay
By C4FM repeaters
By DMR repeaters
By packet digipeaters

What does the packet path WIDE3-1 designate?

Three stations are allowed on frequency, one transmitting at a time
Three subcarriers are permitted, subcarrier one is being used
Three digipeater hops are requested with one remaining
Three internet gateway stations may receive one transmission

What type of modulation is used by JT65?

Multitone AFSK
PSK
RTTY
QAM

What type of packet frame is used to transmit APRS beacon data?

Acknowledgement
Burst
Unnumbered Information
Connect

What digital protocol is used by APRS?

PACTOR
QAM
AX.25
AMTOR

Which of the following is a method for establishing EME contacts?

Time-synchronous transmissions alternating between stations
Storing and forwarding digital messages
Judging optimum transmission times by monitoring beacons reflected from the moon
High-speed CW identification to avoid fading

What is the characteristic of the JT65 mode?

Uses only a 65 Hz bandwidth
Decodes signals with a very low signal-to-noise ratio
Symbol rate is 65 baud
Permits fast-scan TV transmissions over narrow bandwidth

What technology is used for real-time tracking of balloons carrying amateur radio transmitters?

FT8
Bandwidth compressed LORAN
APRS
PACTOR III

Which of the following digital modes is designed for EME communications?

MSK144
PACTOR III
WSPR
Q65

What information replaces signal-to-noise ratio when using the FT8 or FT4 modes in a VHF contest?

RST report
State abbreviation
Serial number
Grid square

Which of the following digital modes is designed for meteor scatter communications?

WSPR
MSK144
Hellschreiber
APRS

What indicates the delay between a control operator action and the corresponding change in the transmitted signal?

Jitter
Hang time
Latency
Anti-VOX

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Send your full call sign once or twice
Send only the last two letters of your call sign until you make contact
Send your full call sign and grid square
Send the call sign of the DX station three times, the words “this is,” then your call sign three times

Why do DX stations often transmit and receive on different frequencies?

Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
To separate the calling stations from the DX station
To improve operating efficiency by reducing interference
All these choices are correct

What type of equipment is commonly used to implement an amateur radio mesh network?

A 2-meter VHF transceiver with a 1,200-baud modem
A computer running EchoLink to provide interface from the radio to the internet
A wireless router running custom firmware
A 440 MHz transceiver with a 9,600-baud modem

Which of the following contacts may be confirmed through the Logbook of The World (LoTW)?

Special event contacts between stations in the US
Contacts between a US station and a non-US station
Contacts for Worked All States credit
All these choices are correct

What is the Cabrillo format?

A standard for submission of electronic contest logs
A method of exchanging information during a contest QSO
The most common set of contest rules
A digital protocol specifically designed for rapid contest exchanges

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

At the top of each band, usually in a segment reserved for contests
In the middle of each band, usually on the national calling frequency
In the weak signal segment of the band, with most of the activity near the calling frequency
In the middle of the band, usually 25 kHz above the national calling frequency

What is the function of a DX QSL Manager?

Allocate frequencies for DXpeditions
Handle the receiving and sending of confirmations for a DX station
Run a net to allow many stations to contact a rare DX station
Communicate to a DXpedition about propagation, band openings, pileup conditions, etc.

Which of the following frequencies can be used for amateur radio mesh networks?

HF frequencies where digital communications are permitted
Frequencies shared with various unlicensed wireless data services
Cable TV channels 41-43
The 60-meter band channel centered on 5373 kHz

From which of the following bands is amateur radio contesting generally excluded?

30 meters
6 meters
70 centimeters
33 centimeters

Which of the following file formats is used for exchanging amateur radio log data?

NEC
ARLD
ADIF
OCF

What indicator is required to be used by US-licensed operators when operating a station via remote control and the remote transmitter is located in the US?

/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
/R# where # is the district of the remote station
/ followed by the ARRL Section of the remote station
No additional indicator is required

What signals SSTV receiving software to begin a new picture line?

Specific tone frequencies
Elapsed time
Specific tone amplitudes
A two-tone signal

What is the function of the vertical interval signaling (VIS) code sent as part of an SSTV transmission?

To lock the color burst oscillator in color SSTV images
To identify the SSTV mode being used
To provide vertical synchronization
To identify the call sign of the station transmitting

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Tone frequency
Tone amplitude
Sync amplitude
Sync frequency

What kind of receiver can be used to receive and decode SSTV using the Digital Radio Mondiale (DRM) protocol?

CDMA
AREDN
AM
SSB

What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70-centimeter band?

Transmitting on channels shared with cable TV
Using converted satellite TV dishes
Transmitting on the abandoned TV channel 2
Using USB and demodulating the signal with a computer sound card

Which types of modulation are used for amateur television DVB-T signals?

FM and FSK
QAM and QPSK
AM and OOK
All these choices are correct

What is vestigial sideband modulation?

Amplitude modulation in which one complete sideband and a portion of the other are transmitted
A type of modulation in which one sideband is inverted
Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation

Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions?

The vestigial sideband carries the audio information
The vestigial sideband contains chroma information
Vestigial sideband reduces the bandwidth while increasing the fidelity of low frequency video components
Vestigial sideband provides high frequency emphasis to sharpen the picture

How is color information sent in analog SSTV?

Color lines are sent sequentially
Color information is sent on a 2.8 kHz subcarrier
Color is sent in a color burst at the end of each line
Color is amplitude modulated on the frequency modulated intensity signal

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

By scanning two fields simultaneously
By scanning each field from bottom-to-top
By scanning lines from left-to-right in one field and right-to-left in the next
By scanning odd-numbered lines in one field and even-numbered lines in the next

How many horizontal lines make up a fast-scan (NTSC) television frame?

30
60
525
1080

In digital television, what does a coding rate of 3/4 mean?

25% of the data sent is forward error correction data
Data compression reduces data rate by 3/4
1/4 of the time interval is used as a guard interval
Three, four-bit words are used to transmit each pixel

Which of the following techniques is used by digital satellites to relay messages?

Digipeating
Store-and-forward
Multisatellite relaying
Node hopping

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

To upload operational software for the transponder
To delay download of telemetry between satellites
To hold digital messages in the satellite for later download
To relay messages between satellites

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

A linearly polarized antenna
A circularly polarized antenna
An isotropic antenna
A log-periodic dipole array

What type of satellite appears to stay in one position in the sky?

HEO
Geostationary
Geomagnetic
LEO

What do the terms "L band" and "S band" specify?

The 23- and 13-centimeter bands
The 2-meter and 70-centimeter bands
FM and digital store-and-forward systems
Which sideband to use

Why should effective radiated power (ERP) be limited to a satellite that uses a linear transponder?

To prevent creating errors in the satellite telemetry
To avoid reducing the downlink power to all other users
To prevent the satellite from emitting out-of-band signals
To avoid interfering with terrestrial QSOs

Which of the following types of signals can be relayed through a linear transponder?

FM and CW
SSB and SSTV
PSK and packet
All these choices are correct

What are Keplerian elements?

Parameters that define the orbit of a satellite
Phase reversing elements in a Yagi antenna
High-emission heater filaments used in magnetron tubes
Encrypting codes used for spread spectrum modulation

What do the letters in a satellite's mode designator specify?

Power limits for uplink and downlink transmissions
The location of the ground control station
The polarization of uplink and downlink signals
The uplink and downlink frequency ranges

What is meant by the "mode" of an amateur radio satellite?

Whether the satellite is in a low earth or geostationary orbit
The satellite's uplink and downlink frequency bands
The satellite's orientation with respect to the Earth
Whether the satellite is in a polar or equatorial orbit

How is an upload signal processed by an inverting linear transponder?

The signal is detected and remodulated on the reverse sideband
The signal is passed through a nonlinear filter
The signal is reduced to I and Q components, and the Q component is filtered out
The signal is mixed with a local oscillator signal and the difference product is transmitted

Which of the following is characteristic of an inverting linear transponder?

Doppler shift is reduced because the uplink and downlink shifts are in opposite directions
Signal position in the band is reversed
Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
All these choices are correct

What is the direction of an ascending pass for an amateur satellite?

From west to east
From east to west
From south to north
From north to south

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

It must produce full legal output when driven by not more than 5 watts of mean RF input power
It must have received an Underwriters Laboratory certification for electrical safety as well as having met IEEE standard 14.101(B)
It must exhibit a gain of less than 23 dB when driven by 10 watts or less
It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power

Who may be the control operator of an auxiliary station?

Any licensed amateur operator
Only Technician, General, Advanced, or Amateur Extra class operators
Only General, Advanced, or Amateur Extra class operators
Only Amateur Extra class operators

Which of the following cannot be transmitted over an amateur radio mesh network?

Third party traffic
Email
Messages encoded to obscure their meaning
All these choices are correct

Which of the following types of amateur station communications are prohibited?

Communications transmitted for hire or material compensation, except as otherwise provided in the rules
Communications that have political content, except as allowed by the Fairness Doctrine
Communications that have religious content
Communications in a language other than English

When may an amateur station send a message to a business?

When the pecuniary interest of the amateur or his or her employer is less than $25
When the pecuniary interest of the amateur or his or her employer is less than $50
At no time
When neither the amateur nor their employer has a pecuniary interest in the communications

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

To provide for experimental amateur communications
To allow use of a special event call sign
To allow a VE group with less than three VEs to administer examinations in a remote, sparsely populated area
To allow a licensee who has passed an upgrade exam to operate with upgraded privileges while waiting for posting on the FCC database

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

440 MHz - 450 MHz
53 MHz - 54 MHz
222 MHz - 223 MHz
420 MHz - 430 MHz

Which of the following geographic descriptions approximately describes "Line A"?

A line roughly parallel to and south of the border between the US and Canada
A line roughly parallel to and west of the US Atlantic coastline
A line roughly parallel to and north of the border between the US and Mexico
A line roughly parallel to and east of the US Pacific coastline

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Gain is less than 23 dB when driven by power of 10 watts or less
The equipment dealer assembled it from a kit
It was manufactured and certificated in a country which has a reciprocal certification agreement with the FCC
It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station

What privileges are authorized in the US to persons holding an amateur service license granted by the government of Canada?

None, they must obtain a US license
Full privileges of the General class license on the 80-, 40-, 20-, 15-, and 10-meter bands
The operating terms and conditions of the Canadian amateur service license, not to exceed US Amateur Extra class license privileges
Full privileges, up to and including those of the Amateur Extra class license, on the 80-, 40-, 20-, 15-, and 10-meter bands

On what frequencies are spread spectrum transmissions permitted?

Only on amateur frequencies above 50 MHz
Only on amateur frequencies above 222 MHz
Only on amateur frequencies above 420 MHz
Only on amateur frequencies above 144 MHz

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Photocopy all examination documents and forward them to the FCC for processing
Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
Issue the examinee the new or upgrade license
All these choices are correct

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

They must collect and send the documents directly to the FCC
They must collect and submit the documents to the coordinating VEC for grading
They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
They must return the documents to the applicant for submission to the FCC according to the FCC instructions

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
A fine of up to $1,000 per occurrence
A sentence of up to one year in prison
All these choices are correct

To which of the following examinees may a VE not administer an examination?

Employees of the VE
Friends of the VE
Relatives of the VE as listed in the FCC rules
All these choices are correct

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Warn the candidate that continued failure to comply will result in termination of the examination
Immediately terminate the candidate's examination
Allow the candidate to complete the examination, but invalidate the results
Immediately terminate everyone's examination and close the session

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

The VEC coordinating the session
The designated monitoring VE
Each administering VE
Only the VE session manager

What must the VE team do with the application form if the examinee does not pass the exam?

Maintain the application form with the VEC's records
Return the application document to the examinee
Send the application form to the FCC and inform the FCC of the grade
Destroy the application form

What is required to be accredited as a Volunteer Examiner?

Each General, Advanced and Amateur Extra class operator is automatically accredited as a VE when the license is granted
The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
The prospective VE must obtain accreditation from the FCC
A VEC must confirm that the VE applicant meets FCC requirements to serve as an examiner

What is a Volunteer Examiner Coordinator?

A person who has volunteered to administer amateur operator license examinations
An organization paid by the volunteer examiner team to publicize and schedule examinations
An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
The person who has entered into an agreement with the FCC to be the VE session manager

Who is tasked by Part 97 with maintaining the pools of questions for all US amateur license examinations?

The VEs
The FCC
The VECs
The ARRL

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
Teaching an amateur operator license examination preparation course
No expenses are authorized for reimbursement
Providing amateur operator license examination preparation training materials

Which of the following amateur stations may transmit one-way communications?

A space station, beacon station, or telecommand station
A local repeater or linked repeater station
A message forwarding station or automatically controlled digital station
All these choices are correct

Which amateur stations are eligible to operate as Earth stations?

Any amateur licensee who has successfully completed the AMSAT space communications course
Only those of General, Advanced or Amateur Extra class operators
Only those of Amateur Extra class operators
Any amateur station, subject to the privileges of the class of operator license held by the control operator

Which amateur stations are eligible to be telecommand stations of space stations, subject to the privileges of the class of operator license held by the control operator of the station?

Any amateur station approved by AMSAT
Any amateur station so designated by the space station licensee
Any amateur station so designated by the ITU
All these choices are correct

Which UHF amateur bands have frequencies authorized for space stations?

70 centimeters only
70 centimeters and 13 centimeters
70 centimeters and 33 centimeters
33 centimeters and 13 centimeters

Which VHF amateur bands have frequencies authorized for space stations?

6 meters and 2 meters
6 meters, 2 meters, and 1.25 meters
2 meters and 1.25 meters
2 meters

Which group of HF amateur bands include allocations for space stations?

40 meters, 20 meters, 15 meters, and 10 meters
30 meters, 17 meters, and 10 meters
Only 10 meters
Satellite operation is permitted on all HF bands

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

1 watt
2 watts
5 watts
100 watts

What must be posted at the location of a station being operated by telecommand on or within 50 kilometers of the Earth's surface?

A photocopy of the station license
A label with the name, address, and telephone number of the station licensee
A label with the name, address, and telephone number of the control operator
All these choices are correct

Which of the following is required in the identification transmissions from a balloon-borne telemetry station?

Call sign
The output power of the balloon transmitter
The station's six-character Maidenhead grid locator
All these choices are correct

What is a space telecommand station?

An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
An amateur station that transmits communications to initiate, modify, or terminate functions of a space station
An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth

Which of the following may transmit encrypted messages?

Telecommand signals to terrestrial repeaters
Telecommand signals from a space telecommand station
Auxiliary relay links carrying repeater audio
Mesh network backbone nodes

What is the definition of telemetry?

One-way transmission of measurements at a distance from the measuring instrument
Two-way transmissions in excess of 1000 feet
Two-way transmissions of data
One-way transmission that initiates, modifies, or terminates the functions of a device at a distance

In what portion of the 630-meter band are phone emissions permitted?

None
Only the top 3 kHz
Only the bottom 3 kHz
The entire band

Which of the following operating arrangements allows an FCC-licensed US citizen to operate in many European countries, and amateurs from many European countries to operate in the US?

CEPT
IARP
ITU reciprocal license
All these choices are correct

What is the maximum mean power level for a spurious emission below 30 MHz with respect to the fundamental emission?

- 43 dB
- 53 dB
- 63 dB
- 73 dB

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

0.5
1
2
3

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

30 seconds
3 minutes
5 minutes
10 minutes

What notifications must be given before transmitting on the 630- or 2200-meter bands?

A special endorsement must be requested from the FCC
An environmental impact statement must be filed with the Department of the Interior
Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
Operators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

You must identify in the official language of the country in which you are operating
The US embassy must approve of your operation
You must have a copy of FCC Public Notice DA 16-1048
You must append "/CEPT" to your call sign

Under what situation may a station transmit third party communications while being automatically controlled?

Never
Only when transmitting RTTY or data emissions
Only when transmitting SSB or CW
On any mode approved by the National Telecommunication and Information Administration

What is an IARP?

A permit that allows US amateurs to operate in certain countries of the Americas
The internal amateur radio practices policy of the FCC
An indication of increased antenna reflected power
A forecast of intermittent aurora radio propagation

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200-meter or 630-meter band?

Operators must not operate until approval is received
Operators may operate after 30 days, providing they have not been told that their station is within 1 kilometer of PLC systems using those frequencies
Operators may not operate until a test signal has been transmitted in coordination with the local power company
Operations may commence immediately, and may continue unless interference is reported by the UTC

Which of the following apply to communications transmitted to amateur stations in foreign countries?

Third party traffic must be limited to that intended for the exclusive use of government and non-Government Organization (NGOs) involved in emergency relief activities
All transmissions must be in English
Communications must be limited to those incidental to the purpose of the amateur service and remarks of a personal nature
All these choices are correct

What is the maximum bandwidth for a data emission on 60 meters?

60 Hz
170 Hz
1.5 kHz
2.8 kHz

What does PRB-1 require of state and local regulations affecting amateur radio antenna size and structures?

No limitations may be placed on antenna size or placement
Reasonable accommodations of amateur radio must be made
Such structures must be permitted when use for emergency communications can be demonstrated
Such structures must be permitted if certified by a registered professional engineer

What frequencies are authorized to an amateur station operating under RACES rules?

All amateur service frequencies authorized to the control operator
Specific segments in the amateur service MF, HF, VHF, and UHF bands
Specific local government channels
All these choices are correct

Which amateur stations may be operated under RACES rules?

Only those club stations licensed to Amateur Extra class operators
Any FCC-licensed amateur station except a Technician class
Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
Only stations meeting the FCC Part 97 technical standards for operation during an emergency

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

The amateur station must cease operation
The amateur station must cease operation on all frequencies below 30 MHz
The amateur station must cease operation on all frequencies above 30 MHz
The amateur station must avoid transmitting during certain hours on frequencies that cause the interference

To what type of regulations does PRB-1 apply?

Homeowners associations
FAA tower height limits
State and local zoning
Use of wireless devices in vehicles

Which of the following additional rules apply if you are erecting an amateur station antenna structure at a site at or near a public use airport?

You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
You may have to enter the height above ground in meters, and the latitude and longitude in degrees, minutes, and seconds on the FAA website
You must file an Environmental Impact Statement with the EPA before construction begins
You must obtain a construction permit from the airport zoning authority per Part 119 of the FAA regulations

What is the National Radio Quiet Zone?

An area surrounding the FCC monitoring station in Laurel, Maryland
An area in New Mexico surrounding the White Sands Test Area
An area surrounding the National Radio Astronomy Observatory
An area in Florida surrounding Cape Canaveral

What must the control operator of a repeater operating in the 70-centimeter band do if a radiolocation system experiences interference from that repeater?

Reduce the repeater antenna HAAT (Height Above Average Terrain)
File an FAA NOTAM (Notice to Air Missions) with the repeater system's ERP, call sign, and six-character grid locator
Cease operation or make changes to the repeater that mitigate the interference
All these choices are correct

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

1 mile
3 miles
10 miles
30 miles

Which of the following is an acceptable bandwidth for digital voice or slow-scan TV transmissions made on the HF amateur bands?

3 kHz
10 kHz
15 kHz
20 kHz

Which of the following constitutes a spurious emission?

An amateur station transmission made without the proper call sign identification
A signal transmitted to prevent its detection by any station other than the intended recipient
Any transmitted signal that unintentionally interferes with another licensed radio station and whose levels exceed 40 dB below the fundamental power level
An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted

What licensing is required when operating an amateur station aboard a US-registered vessel in international waters?

Any amateur license with an FCC Marine or Aircraft endorsement
Any FCC-issued amateur license
Only General class or higher amateur licenses
An unrestricted Radiotelephone Operator Permit

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Its operation must be approved by the master of the ship or the pilot in command of the aircraft
The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
The amateur station must operate only in specific segments of the amateur service HF and VHF bands

Except in some parts of Alaska, what is the maximum power permitted on the 630-meter band?

50 watts PEP (peak envelope power)
100 watts PEP (peak envelope power)
1 watt EIRP (equivalent isotropic radiated power)
5 watts EIRP (equivalent isotropic radiated power)

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

The control operator of the packet bulletin board station
The control operator of the originating station
The control operators of all the stations in the system
The control operators of all the stations in the system not authenticating the source from which they accept communications

What is the maximum power permitted on the 2200-meter band?

50 watts PEP (peak envelope power)
100 watts PEP (peak envelope power)
1 watt EIRP (equivalent isotropic radiated power)
5 watts EIRP (equivalent isotropic radiated power)

What is the required transmit frequency of a CW signal for channelized 60 meter operation?

At the lowest frequency of the channel
At the center frequency of the channel
At the highest frequency of the channel
On any frequency where the signal's sidebands are within the channel

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Only a person with an FCC Marine Radio license grant
Only a person named in an amateur station license grant
Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit

May an Extra class operator answer the CQ of a station on 3.601 MHz LSB phone?

Yes, the entire signal will be inside the SSB allocation for Extra class operators
Yes, the displayed frequency is within the 75-meter phone band segment
No, the sideband components will extend beyond the edge of the phone band segment
No, US stations are not permitted to use phone emissions below 3.610 MHz

What is the highest legal carrier frequency on the 20-meter band for transmitting a 2.8 kHz wide USB data signal?

14.0708 MHz
14.1002 MHz
14.1472 MHz
14.3490 MHz

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

The exact lower band edge
300 Hz above the lower band edge
1 kHz above the lower band edge
3 kHz above the lower band edge

Why is it not legal to transmit a 3 kHz bandwidth USB signal with a carrier frequency of 14.348 MHz?

USB is not used on 20-meter phone
The lower 1 kHz of the signal is outside the 20-meter band
14.348 MHz is outside the 20-meter band
The upper 1 kHz of the signal is outside the 20-meter band