Amateur Extra Class Practice Test

Select the most correct answer for each question, then submit your practice test to check your score. This practice test randomly pulls one question from each topic in the Amateur Extra pool.

Good Luck!


When several electrolytic filter capacitors are connected in series to increase the operating voltage of a power supply filter circuit, why should resistors be connected across each capacitor?

To equalize, as much as possible, the voltage drop across each capacitor
To provide a safety bleeder to discharge the capacitors when the supply is off
To provide a minimum load current to reduce voltage excursions at light loads
All of these choices are correct


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

The IC input can be damaged
The comparator changes its output state
The comparator enters latch-up
The feedback loop becomes unstable


What does SAR measure?

Synthetic Aperture Ratio of the human body
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 the term for the blocking of one FM phone signal by another, stronger FM phone signal?

Cross-modulation interference
Capture effect
Frequency discrimination


What is one common use for PIN diodes?

As a constant current source
As a constant voltage source
As an RF switch
As a high voltage rectifier


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, multiplied by the square root of inductance L multiplied by capacitance C
It equals 2 multiplied by Pi, multiplied by frequency, multiplied by inductance


What is the relationship between symbol rate and baud?

They are the same
Baud is twice the symbol rate
Symbol rate is only used for packet-based modes
Baud is only used for RTTY


What is a solid state relay?

A relay using 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 passive delay line


Which of the following is true of a charge-coupled device (CCD)?

Its phase shift changes rapidly with frequency
It is a CMOS analog-to-digital converter
It samples an analog signal and passes it in stages from the input to the output
It is used in a battery charger circuit


What is the maximum power output permitted on the 60 meter band?

50 watts PEP effective radiated power relative to an isotropic radiator
50 watts PEP effective radiated power relative to a dipole
100 watts PEP effective radiated power relative to the gain of a half-wave dipole
100 watts PEP effective radiated power relative to an isotropic radiator


What is susceptance?

The magnetic impedance of a circuit
The ratio of magnetic field to electric field
The inverse of reactance
A measure of the efficiency of a transformer


How many turns will be required to produce a 1-mH inductor using a core that has an inductance index (A L) value of 523 millihenrys/1000 turns?

2 turns
4 turns
43 turns
229 turns


What is a characteristic of a grounded-grid amplifier?

High power gain
High filament voltage
Low input impedance
Low bandwidth


What is an Earth station in the amateur satellite service?

An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
An amateur station that is not able to communicate using amateur satellites
An amateur station that transmits telemetry consisting of measurements of the upper atmosphere
Any amateur station on the surface of the Earth


What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Only beacon, repeater or space stations
Only auxiliary, repeater or space stations
Only earth stations, repeater stations or model craft
Only auxiliary, beacon or space stations


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

2.5 to 1
25 to 1
1 to 1
100 to 1


What term best describes the interactions at the load end of a mismatched transmission line?

Characteristic impedance
Reflection coefficient
Velocity factor
Dielectric constant


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 upper and lower case text
It uses one character as a shift code to send numeric and special characters


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



What is a phase-locked loop circuit?

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 input


What are the distinguishing features 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


What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 7.2 MHz?

10 meters
6.9 meters
24 meters
50 meters


What is a depletion-mode 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
Any FET without a channel
Any FET for which holes are the majority carriers


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

30 m
6 m
2 m
33 cm


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

A balanced modulator on the audio amplifier
A reactance modulator on the oscillator
A reactance modulator on the final amplifier
A balanced modulator on the oscillator


What current flows equally on all conductors of an unshielded multi-conductor cable?

Differential-mode current
Common-mode current
Reactive current only
Return current


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


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
Circuit Diagram


By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

By approximately 15 percent of the distance
By approximately twice the distance
By approximately 50 percent of the distance
By approximately four times the distance


What is the effect of aliasing in a digital or computer-based oscilloscope?

False signals are displayed
All signals will have a DC offset
Calibration of the vertical scale is no longer valid
False triggering occurs


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


Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Your transmit frequency is incorrect
The protocol version you are using is not supported by the digital station
Another station you are unable to hear is using the frequency
All of these choices are correct


How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

200 watts
1000 watts
1600 watts
600 watts


Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Install a good radial system
Isolate the coax shield from ground
Shorten the radiating element
Reduce the diameter of the radiating element


Which of the following is a characteristic of a good DC voltmeter?

High reluctance input
Low reluctance input
High impedance input
Low impedance input


What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

SWR vs frequency charts
Polar plots of the far field elevation and azimuth patterns
Antenna gain
All of these choices are correct


What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?



What privileges are authorized in the U.S. to persons holding an amateur service license granted by the Government of Canada?

None, they must obtain a U.S. license
All privileges of the Extra Class license
The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Extra Class privileges
Full privileges, up to and including those of the Extra Class License, on the 80, 40, 20, 15, and 10 meter bands


Which of the following represents a capacitive reactance in polar coordinates?

A positive real part
A negative real part
A positive phase angle
A negative phase angle


Which of the following would provide the best RF ground for your station?

A 50 ohm resistor connected to ground
An electrically short connection to a metal water pipe
An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke


What sets the minimum detectable signal level for an SDR 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 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


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
Military Auxiliary Radio System (MARS) channels


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


How does JT65 improve EME communications?

It can decode signals many dB below the noise floor using FEC
It controls the receiver to track Doppler shift
It supplies signals to guide the antenna to track the Moon
All of these choices are correct


What is a characteristic of a monostable multivibrator?

It switches momentarily to the opposite binary state and then returns to its original state after a set time
It produces a continuous square wave oscillating between 1 and 0
It stores one bit of data in either a 0 or 1 state
It maintains a constant output voltage, regardless of variations in the input voltage


How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

The main lobe takeoff angle increases with increasing height
The main lobe takeoff angle decreases with increasing height
The horizontal beam width increases with height
The horizontal beam width decreases with height


Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

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


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 one or more wavelengths long


What is the minimum passing score on amateur operator license examinations?

Minimum passing score of 70%
Minimum passing score of 74%
Minimum passing score of 80%
Minimum passing score of 77%