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 describes frequency division multiplexing?

The transmitted signal jumps from band to band at a predetermined rate
Two or more information streams are merged into a baseband, which then modulates the transmitter
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


How does the beamwidth of an antenna vary as the gain is increased?

It increases geometrically
It increases arithmetically
It is essentially unaffected
It decreases


Which of the following parameters determines the bandwidth of a digital or computer-based oscilloscope?

Input capacitance
Input impedance
Sampling rate
Sample resolution


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

100 ohms
1000 ohms
Very low
Very high


How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

At half the rate of the highest frequency component of the signal
At 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 of the following can divide the frequency of a pulse train by 2?

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


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


What is the relationship between the 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 do the terms L band and S band specify with regard to satellite communications?

The 23 centimeter and 13 centimeter bands
The 2 meter and 70 centimeter bands
FM and Digital Store-and-Forward systems
Which sideband to use


What is meant by automatic control of a station?

The use of devices and procedures for control so that the control operator does not have to be present at a control point
A station operating with its output power controlled automatically
Remotely controlling a station's antenna pattern through a directional control link
The use of a control link between a control point and a locally controlled station


What special operating frequency restrictions are imposed on slow scan TV transmissions?

None; they are allowed on all amateur frequencies
They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
They are restricted to phone band segments and their bandwidth can be no greater than that of a voice signal of the same modulation type
They are not permitted above 54 MHz


How is positive feedback supplied in a Pierce oscillator?

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


What is an effective way of matching a feed line to a VHF or UHF antenna when the impedances of both the antenna and feed line are unknown?

Use a 50 ohm 1:1 balun between the antenna and feed line
Use the universal stub matching technique
Connect a series-resonant LC network across the antenna feed terminals
Connect a parallel-resonant LC network across the antenna feed terminals


Which of the following constitutes a spurious emission?

An amateur station transmission made at random 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
An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted


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 propagation
Polar paths


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

Extremely high reverse breakdown voltage
Ability to dissipate large amounts of power
Reverse bias controls its forward voltage drop
A large region of intrinsic material


What is the maximum bandwidth for a data emission on 60 meters?

60 Hz
170 Hz
1.5 kHz
2.8 kHz


What is the effect of intermodulation products in a linear power amplifier?

Transmission of spurious signals
Creation of parasitic oscillations
Low efficiency
All of these choices are correct


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


Which of the following semiconductor materials contains excess free electrons?

Insulated gate


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

0.1 V
0.5 V
1.5 V
12 V


Where are the questions for all written U.S. amateur license examinations listed?

In FCC Part 97
In a question pool maintained by the FCC
In a question pool maintained by all the VECs
In the appropriate FCC Report and Order


What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?

Many similar gates are less expensive than a mixture of gate types
Complex logic functions can be created in a single integrated circuit
A PGA contains its own internal power supply
All of these choices are correct


What type of transmission is most often used for a ham radio mesh network?

Spread spectrum in the 2.4 GHz band
Multiple Frequency Shift Keying in the 10 GHz band
Store and forward on the 440 MHz band
Frequency division multiplex in the 24 GHz band


What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

They are bent toward the magnetic poles
Their polarization is randomly modified
They become elliptically polarized
They become phase-locked


What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and which uses a 455 kHz IF frequency?

13.845 MHz
14.755 MHz
14.445 MHz
15.210 MHz


What impedance does a 1/2 wavelength transmission line present to a generator when the line is open 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 generator


How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

704 W
355 W
252 W
1.42 mW


Which type of detector is used for demodulating SSB signals?

Phase detector
Product detector
Phase comparator


In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

36 dB
18 dB
24 dB
14 dB
Circuit Diagram


Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

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


If you plot the impedance of a circuit using the rectangular coordinate system and find the impedance point falls on the right side of the graph on the horizontal axis, what do you know about the circuit?

It has to be a direct current circuit
It contains resistance and capacitive reactance
It contains resistance and inductive reactance
It is equivalent to a pure resistance


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 is the half-power bandwidth of a parallel 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


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 effect of a terminating resistor on a rhombic 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 type of chart is shown in Figure E9-3?

Smith chart
Free space radiation directivity chart
Elevation angle radiation pattern chart
Azimuth angle radiation pattern chart
Circuit Diagram


What is the most common method of reducing key clicks?

Increase keying waveform rise and fall times
Low-pass filters at the transmitter output
Reduce keying waveform rise and fall times
High-pass filters at the transmitter output


What do the letters FEC mean as they relate to digital operation?

Forward Error Correction
First Error Correction
Fatal Error Correction
Final Error Correction


Which of the following best describes electromagnetic waves traveling in free space?

Electric and magnetic fields become aligned as they travel
The energy propagates through a medium with a high refractive index
The waves are reflected by the ionosphere and return to their source
Changing electric and magnetic fields propagate the energy


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


What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Greater harmonic suppression
Higher efficiency
Lower losses
Greater transformation range


What three test loads are used to calibrate a standard 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 is the most common input and output impedance of circuits that use MMICs?

50 ohms
300 ohms
450 ohms
10 ohms


What is one of the potential hazards of using microwaves in the amateur radio bands?

Microwaves are ionizing radiation
The high gain antennas commonly used can result in high exposure levels
Microwaves often travel long distances by ionospheric reflection
The extremely high frequency energy can damage the joints of antenna structures


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 GPS unit can automatically transmit information to show a mobile station's position during the event
All of these choices are correct


What class of licensee is authorized to be the control operator of a space station?

All except Technician Class
Only General, Advanced or Amateur Extra Class
Any class with appropriate operator privileges
Only Amateur Extra Class


Which of the following types of receiver noise can often be reduced with a DSP noise filter?

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


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

0.1 Hz
0.3 kHz
0.5 kHz
1.0 kHz


What is one reason for using ferrite cores rather than powdered-iron in an inductor?

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