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 primary reason that a high-frequency switching type high voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

The inverter design does not require any output filtering
It uses a diode bridge rectifier for increased output
The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
It uses a large power factor compensation capacitor to create free power from the unused portion of the AC cycle


What does the value of Bz (B sub Z) represent?

Geomagnetic field stability
Critical frequency for vertical transmissions
Direction and strength of the interplanetary magnetic field
Duration of long-delayed echoes


What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Analog-to-digital conversion speed of the soundcard
Amount of memory on the soundcard
Q of the interface of the interface circuit
All of these choices are correct


Which of the following digital modes is especially designed for use for meteor scatter signals?



What is a frequency discriminator stage in a FM receiver?

An FM generator circuit
A circuit for filtering two closely adjacent signals
An automatic band-switching circuit
A circuit for detecting FM signals


What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

1 W
1.5 W
10 W
1.5 kW


Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Signals which are constant at all IF levels
Signals which appear across a wide bandwidth
Signals which appear at one IF but not another
Signals which have a sharply peaked frequency distribution


What third family of circles is often added to a Smith chart during the process of solving problems?

Standing wave ratio circles
Antenna-length circles
Coaxial-length circles
Radiation-pattern circles


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


Which of the following represents an inductive reactance in polar coordinates?

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


What is meant by antenna bandwidth?

Antenna length divided by the number of elements
The frequency range over which an antenna satisfies a performance requirement
The angle between the half-power radiation points
The angle formed between two imaginary lines drawn through the element ends


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

600 Hz
3 kHz
2 MHz
6 MHz


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
Network resistances are substituted for load resistances and reactances are matched to the resistances


What type of equipment is commonly used to implement a ham 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 standard wireless router running custom software
A 440 MHz transceiver with a 9600 baud modem


What is one way to predict the location of a satellite at a given time?

By means of the Doppler data for the specified satellite
By subtracting the mean anomaly from the orbital inclination
By adding the mean anomaly to the orbital inclination
By calculations using the Keplerian elements for the specified satellite


How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from an isotropic antenna, assuming each is driven by the same amount of power?

The total amount of radiation from the directional antenna is increased by the gain of the antenna
The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
They are the same
The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna


Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna
Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable
Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna


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 impedance does a 1/4 wavelength transmission line present to a generator when the line is shorted at the far end?

Very high impedance
Very low impedance
The same as the characteristic impedance of the transmission line
The same as the generator output impedance


Which of the following can be used as a relative measurement of the Q for a series-tuned circuit?

The inductance to capacitance ratio
The frequency shift
The bandwidth of the circuit's frequency response
The resonant frequency of the circuit


Which of the following components can be used to reduce thermal drift in crystal oscillators?

NP0 capacitors
Toroidal inductors
Wirewound resistors
Non-inductive resistors


What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historical Places?

A proposal must be submitted to the National Park Service
A letter of intent must be filed with the National Audubon Society
An Environmental Assessment must be submitted to the FCC
A form FSD-15 must be submitted to the Department of the Interior


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 phase relationship between the current through and the voltage across a series resonant circuit at resonance?

The voltage leads the current by 90 degrees
The current leads the voltage by 90 degrees
The voltage and current are in phase
The voltage and current are 180 degrees out of phase


How many flip-flops are required to divide a signal frequency by 4?



Which of the following best describes the Volunteer Examiner accreditation process?

Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
The prospective VE obtains accreditation from the FCC
The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner


What is a Programmable Logic Device (PLD)?

A device to control industrial equipment
A programmable collection of logic gates and circuits in a single integrated circuit
Programmable equipment used for testing digital logic integrated circuits
An algorithm for simulating logic functions during circuit design


What is the purpose of the preselector in a communications receiver?

To store often-used frequencies
To provide a range of AGC time constants
To increase rejection of unwanted signals
To allow selection of the optimum RF amplifier device


Which type of slug material decreases inductance when inserted into a coil?



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

60 Hz
170 Hz
1.5 kHz
2.8 kHz


In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Circuit Diagram


Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

18.110 MHz - 18.168 MHz
24.940 MHz - 24.990 MHz
10.100 MHz - 10.150 MHz
29.500 MHz - 29.700 MHz


What is the function of a sense antenna?

It modifies the pattern of a DF antenna array to provide a null in one direction
It increases the sensitivity of a DF antenna array
It allows DF antennas to receive signals at different vertical angles
It provides diversity reception that cancels multipath signals


What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

15.36 kHz
9.6 kHz
4.8 kHz
5.76 kHz


What are the majority charge carriers in N-type semiconductor material?

Free electrons
Free protons
Free neutrons


What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

The ability to retrieve information from a single signal even in the presence of other strong signals
Plate current that is controlled by a control grid
Nearly infinite gain, very high input impedance, and very low output impedance
Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range


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


Which of the following could account for hearing an echo on the received signal of a distant station?

High D layer absorption
Meteor scatter
Transmit frequency is higher than the MUF
Receipt of a signal by more than one path


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 magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Circuit Diagram


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


What is a Class D amplifier?

A type of amplifier that uses switching technology to achieve high efficiency
A low power amplifier that uses a differential amplifier for improved linearity
An amplifier that uses drift-mode FETs for high efficiency
A frequency doubling amplifier


What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Selective fading has occurred
One of the signal filters is saturated
The receiver has drifted 5 kHz from the desired receive frequency
The mark and space signal have been inverted


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

It is unchanged
The sign is reversed
It is shifted by 90 degrees
The susceptance phase angle is the inverse of the reactance phase angle


Which of the following injuries can result from using high-power UHF or microwave transmitters?

Hearing loss caused by high voltage corona discharge
Blood clotting from the intense magnetic field
Localized heating of the body from RF exposure in excess of the MPE limits
Ingestion of ozone gas from the cooling system


What digital process is applied to I and Q signals in order to recover the baseband modulation information?

Fast Fourier Transform
Signal conditioning
Quadrature mixing


Which type of atmospheric structure can create a path for microwave propagation?

The jet stream
Temperature inversion
Wind shear
Dust devil


How does a narrow-band roofing filter affect receiver performance?

It improves sensitivity by reducing front end noise
It improves intelligibility by using low Q circuitry to reduce ringing
It improves dynamic range by attenuating strong signals near the receive frequency
All of these choices are correct


How can the true power be determined in an AC circuit where the voltage and current are out of phase?

By multiplying the apparent power times the power factor
By dividing the reactive power by the power factor
By dividing the apparent power by the power factor
By multiplying the reactive power times the power factor