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!


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



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


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


What is one type of electrical interference that might be caused by a nearby personal computer?

A loud AC hum in the audio output of your station 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


Which of the following describes an emitter follower (or common collector) amplifier?

A two-transistor amplifier with the emitters sharing a common bias resistor
A differential amplifier with both inputs fed to the emitter of the input transistor
An OR circuit with only one emitter used for output
An amplifier with a low impedance output that follows the base input voltage


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


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


Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

The VEC coordinating the session
Each administering VE
The VE session manager


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

A crystalline semiconductor
An ordinary metal
A heavy metal
A liquid semiconductor


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


Which of the following component package types would be most suitable for use at frequencies above the HF range?

Axial lead
Radial lead
Surface mount


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

+10 dB
+15 dB
-20 dB
-30 dB


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


Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

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


What is the bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

0.1 Hz
0.3 kHz
0.5 kHz
1.0 kHz


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


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 Permitted Exposure (MPE) limits
Ensure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits
Ensure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits
Ensure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits


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


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

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


Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?



How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Lower loss
Higher SWR
Smaller reflection coefficient
Lower velocity factor


A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

-174 dBm
-164 dBm
-155 dBm
-148 dBm


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 term for the long path opening that exists between two points on the Earth which are simultaneously near sunrise and sunset?

Sporadic E


Which of the following describes an Extended Double Zepp antenna?

A wideband vertical antenna constructed from precisely tapered aluminum tubing
A portable antenna erected using two push support poles
A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)
An end-fed folded dipole antenna


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

A 2 meter VHF transceiver with a 1200 baud modem
An optical cable connection between the USB ports of 2 separate computers
A wireless router running custom firmware
A 440 MHz transceiver with a 9600 baud modem


Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Multi-satellite relaying
Node hopping


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 two times the power supply voltage
The input switching threshold is about one-half the power supply voltage
Bandwidth is very limited


What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

Amplifier desensitization
Adjacent channel interference


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 operator must have an FCC Marine or Aircraft endorsement on his or her amateur license


What happens to the magnitude of a pure reactance when it is converted to a susceptance?

It is unchanged
The sign is reversed
It is shifted by 90 degrees
It becomes the reciprocal


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 a desired value
Reactive currents are dissipated in matched resistances


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

Successive approximation
Harmonic regeneration
Level shifting
Phase reversal


What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 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
Circuit Diagram


Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Near the center of the vertical radiator
As low as possible on the vertical radiator
As close to the transmitter as possible
At a voltage node


How can an APRS station be used to help support a public service communications activity?

An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
All these choices are correct


What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?



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


What is the effective radiated power relative to a dipole 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?

1977 watts
78.7 watts
420 watts
286 watts


What core material property determines the inductance of an inductor?

Thermal impedance


What is the name of the signal component that carries color information in NTSC video?

Spectral intensity


Why is RF attenuation used when direction-finding?

To narrow the receiver bandwidth
To compensate for isotropic directivity and the antenna effect of feed lines
To increase receiver sensitivity
To prevent receiver overload which reduces pattern nulls


How is positive feedback supplied in a Hartley oscillator?

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


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
Amount of memory
Q of the circuit
All these choices are correct


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

As a rectifier in high current power supplies
As a variable capacitance in an automatic frequency control circuit
As a constant voltage reference in a power supply
As a VHF/UHF mixer or detector


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


Which of the following increases Q for inductors and capacitors?

Lower losses
Lower reactance
Lower self-resonant frequency
Higher self-resonant frequency


Which of the following semiconductor materials contains excess free electrons?

Insulated gate


What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

The gamma match
The delta match
The epsilon match
The stub match


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