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

Insulator impurity
N-type impurity
Acceptor impurity
Donor impurity


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 bandwidth while allowing for simple video detector circuitry
Vestigial sideband provides high frequency emphasis to sharpen the picture


At what time of day can sporadic E propagation occur?

Only around sunset
Only around sunset and sunrise
Only in hours of darkness
Any time


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


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

Successive approximation
Harmonic regeneration
Level shifting
Phase reversal


What impedance does a 1/8-wavelength transmission line present to a 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


What does VOACAP software model?

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


What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

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


What core material property determines the inductance of an inductor?

Thermal impedance


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

23.5 MHz
23.5 kHz
7.12 kHz
7.12 MHz


What do the arcs on a Smith chart represent?

Points with constant resistance
Points with constant reactance


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


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

Reduce received noise
Lightning protection
Reduce RF current flow between pieces of equipment
Reduce RFI to telephones and home entertainment systems


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

Varactor diode
Tunnel diode
Silicon-controlled rectifier
Zener diode


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 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 self-resonate at the hum frequency
To provide fixed DC bias for Q1
Circuit Diagram


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

To provide for experimental amateur communications
To allow regular operation on Land Mobile channels
To provide additional spectrum for personal use
To provide temporary operation while awaiting normal licensing


What is an advantage of using top loading in a shortened HF vertical antenna?

Lower Q
Greater structural strength
Higher losses
Improved radiation efficiency


Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

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 is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

It ensures that each driven element operates in concert with the others to create the desired antenna pattern
It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
It allows single-band antennas to operate on other bands
It creates a low-angle radiation pattern


What is the effective radiated power relative to a dipole 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
2000 watts
126 watts
300 watts


What is an advantage of placing a grounded 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 surroundings, improving the 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


In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

In the same direction as the current
In a direction opposite to the current
In all directions; omni-directional
In a circle around the conductor


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



What notifications must be given before transmitting on the 630 meter 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 Utilities Telecom Council of their call sign and coordinates of the station
Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway


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


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


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 represents capacitive reactance in rectangular notation?



Which of the following frequencies are sometimes 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 through 43
The 60 meter band channel centered on 5373 kHz


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 is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select transistors with high beta
Use a resistor in series with the emitter
All these choices are correct


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


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

Ball grid array


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


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

Antenna analyzers automatically tune your antenna for resonance
Antenna analyzers do not need an external RF source
Antenna analyzers display a time-varying representation of the modulation envelope
All these choices are correct


Which of the following is a circuit that continuously alternates between two states without an external clock?

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


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
25 watts
75 watts


What is an advantage of having a variety of receiver IF 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


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 filter type is described as having 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 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


Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

The VEs
The VECs


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


Which of the following describes a method of establishing EME contacts?

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


How is the signal inverted by an inverting linear transponder?

The signal is detected and remodulated on the reverse sideband
The signal is passed through a non-linear filter
The signal is reduced to I and Q components and the Q component is filtered out
The signal is passed through a mixer and the difference rather than the sum is transmitted