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 advantage of including a parity bit with an ASCII character stream?

Faster transmission rate
The signal can overpower interfering signals
Foreign language characters can be sent
Some types of errors can be detected


What does a value of -174 dBm/Hz represent with regard to the noise floor of a receiver?

The minimum detectable signal as a function of receive frequency
The theoretical noise at the input of a perfect receiver at room temperature
The noise figure of a 1 Hz bandwidth receiver
The galactic noise contribution to minimum detectable signal


What is a Volunteer Examiner Coordinator?

A person who has volunteered to administer amateur operator license examinations
A person who has volunteered to prepare amateur operator license examinations
An organization that has entered into an agreement with the FCC to coordinate amateur operator license examinations
The person who has entered into an agreement with the FCC to be the VE session manager


What is the purpose of Q1 in the circuit shown in Figure E7-3?

It provides negative feedback to improve regulation
It provides a constant load for the voltage source
It increases the current-handling capability of the regulator
It provides D1 with current
Circuit Diagram


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 signals will theoretically generate a third-order intermodulation product with the same level as the input signals
A pair of 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal


What is the approximate bandwidth of a slow-scan TV signal?

600 Hz
3 kHz
2 MHz
6 MHz


Which of the following additional rules apply if you are installing an amateur station antenna 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 FCC rules
No special rules apply if your antenna structure will be less than 300 feet in height
You must file an Environmental Impact Statement with the EPA before construction begins
You must obtain a construction permit from the airport zoning authority


Which amateur service HF bands have frequencies authorized for space stations?

Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
All HF bands


What occurs when an excessive amount of signal energy reaches a mixer circuit?

Spurious mixer products are generated
Mixer blanking occurs
Automatic limiting occurs
A beat frequency is generated


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


What is the common name for a capacitor connected across a transformer secondary that is used to absorb transient voltage spikes?

Clipper capacitor
Trimmer capacitor
Feedback capacitor
Snubber capacitor


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

A figure-8 broadside to the axis of the array
A figure-8 oriented along the axis of the array


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 failure mechanism when a junction diode fails due to excessive current?

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


What is the purpose of the prescaler function on a frequency counter?

It amplifies low level signals for more accurate counting
It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
It prevents oscillation in a low-frequency counter circuit
It divides a higher frequency signal so a low-frequency counter can display the input frequency


What logical operation is performed by an exclusive NOR gate?

It produces logic "0" at its output only if all inputs are logic "0"
It produces logic "1" at its output only if all inputs are logic "1"
It produces logic "0" at its output if any single input is logic "1"
It produces logic "1" at its output if any single input is logic "1"


What do the initials CMOS stand for?

Common Mode Oscillating System
Complementary Mica-Oxide Silicon
Complementary Metal-Oxide Semiconductor
Common Mode Organic Silicon


Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Silicon nitride
Silicon dioxide
Gallium nitride


What is the term for the ratio between the frequency deviation of an RF carrier wave and the modulating frequency of its corresponding FM-phone signal?

FM compressibility
Quieting index
Percentage of modulation
Modulation index


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 describes a method to measure intermodulation distortion in an SSB transmitter?

Modulate the transmitter with two non-harmonically related radio frequencies and observe the RF output with a spectrum analyzer
Modulate the transmitter with two non-harmonically related audio frequencies and observe the RF output with a spectrum analyzer
Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a peak reading wattmeter
Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a logic analyzer


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 allow more precise representation of a signal over time
An error caused by irregular quantization step size
A method of decimation by randomly skipping samples


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 do Hepburn maps predict?

Sporadic E propagation
Locations of auroral reflecting zones
Likelihood of rain-scatter along cold or warm fronts
Probability of tropospheric propagation


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

It is unchanged
The sign is reversed
It is shifted by 90 degrees
The magnitude of the susceptance is the reciprocal of the magnitude of the reactance


What is meant by antenna gain?

The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna
The ratio of the signal in the forward direction to that in the opposite direction
The ratio of the amount of power radiated by an antenna compared to the transmitter output power
The final amplifier gain minus the transmission line losses


What is a use for a Wilkinson divider?

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


What might a sudden rise in radio background noise indicate?

A meteor ping
A solar flare has occurred
Increased transequatorial propagation likely
Long-path propagation is occurring


How can an RF power amplifier be neutralized?

By increasing the driving power
By reducing the driving power
By feeding a 180-degree out-of-phase portion of the output back to the input
By feeding an in-phase component of the output back to the input


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 obstructed by objects of reflection
The region where the shape of the antenna pattern is independent of distance


What is one advantage of using JT65 coding?

Uses only a 65 Hz bandwidth
The ability to decode signals which have a very low signal to noise ratio
Easily copied by ear if necessary
Permits fast-scan TV transmissions over narrow bandwidth


What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

It increases security
It has more possible states than simple binary
It has more resolution than simple binary
It facilitates error detection


What is the efficiency of a photovoltaic cell?

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


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 is the effect of ringing in a filter?

An echo caused by a long time delay
A reduction in high frequency response
Partial cancellation of the signal over a range of frequencies
Undesired oscillations added to the desired signal


What is transequatorial propagation?

Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
Propagation between any two points located on the magnetic equator
Propagation between two continents by way of ducts along the magnetic equator
Propagation between two stations at the same latitude


Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Atmospheric noise is so high that gain over a dipole is not important
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 of these choices are correct


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

Broadband noise
Digital conversion noise
Spurious signals at discrete frequencies
Nyquist limit noise


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

44.72 MHz
22.36 MHz
3.56 MHz
1.78 MHz


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

Make sure signals from your station are less than the controlled MPE limits
Make sure signals from your station are less than the uncontrolled MPE limits
You need only evaluate exposure levels on your own property
Advise your neighbors of the results of your tests


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


What do the two numbers that are used to define a point on a graph using rectangular coordinates represent?

The magnitude and phase of the point
The sine and cosine values
The coordinate values along the horizontal and vertical axes
The tangent and cotangent values


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 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 a common method of generating an SSB signal using digital signal processing?

Mixing products are converted to voltages and subtracted by adder circuits
A frequency synthesizer removes the unwanted sidebands
Emulation of quartz crystal filter characteristics
Combine signals with a quadrature phase relationship


Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

ALE can use any type of control


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 U.S. embassy must approve of your operation
You must bring a copy of FCC Public Notice DA 11-221
You must append "/CEPT" to your call sign


Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

Ignition noise
Broadband white noise
Heterodyne interference
All of these choices are correct


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
Circuit Diagram


What is reactive power?

Wattless, nonproductive power
Power consumed in wire resistance in an inductor
Power lost because of capacitor leakage
Power consumed in circuit Q