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!


Why is an anti-aliasing digital filter required in a digital decimator?

It removes high-frequency signal components that would otherwise be reproduced as lower frequency components
It peaks the response of the decimator, improving bandwidth
It removes low-frequency signal components to eliminate the need for DC restoration
It notches out the sampling frequency to avoid sampling errors


When may an automatically controlled station originate third party communications?

Only when transmitting RTTY or data emissions
When agreed upon by the sending or receiving station
When approved by the National Telecommunication and Information Administration


Which of the following constitutes a spurious emission?

An amateur station transmission made 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 the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted


Which amateur bands typically support long-path propagation?

Only 160 meters to 40 meters
Only 30 meters to 10 meters
160 meters to 10 meters
6 meters to 2 meters


What type of transmission line is used for connections to MMICs?

Miniature coax
Circular waveguide
Parallel wire


Which of the following occurs when a satellite is using an inverted linear transponder?

Doppler shift is reduced because the uplink and downlink shifts are in opposite directions
Signal position in the band is reversed
Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
All these choices are correct


Why might a DX station state that they are listening on another frequency?

Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
To separate the calling stations from the DX station
To improve operating efficiency by reducing interference
All these choices are correct


Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

At the lowest frequency of the channel
At the center frequency of the channel
At the highest frequency of the channel
On any frequency where the signal's sidebands are within the channel


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 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


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

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


In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Circuit Diagram


Why are there separate electric (E) and magnetic (H) field MPE limits?

The body reacts to electromagnetic radiation from both the E and H fields
Ground reflections and scattering make the field strength vary with location
E field and H field radiation intensity peaks can occur at different locations
All 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 the name of the signal component that carries color information in NTSC video?

Spectral intensity


Which of the following amplifier types reduces even-order harmonics?

Class C
Class AB


What does the MDS of a receiver represent?

The meter display sensitivity
The minimum discernible signal
The multiplex distortion stability
The maximum detectable spectrum


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 is an effect of increasing Q in a series resonant circuit?

Fewer components are needed for the same performance
Parasitic effects are minimized
Internal voltages increase
Phase shift can become uncontrolled


When may an amateur station send a message to a business?

When the total money involved does not exceed $25
When the control operator is employed by the FCC or another government agency
When transmitting international third-party communications
When neither the amateur nor his or her employer has a pecuniary interest in the communications


What is one advantage of the JT65 mode?

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 happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

The lobes become more perpendicular to the wire
The lobes align more in the direction of the wire
The vertical angle increases
The front-to-back ratio decreases


Why is de-emphasis commonly used in FM communications receivers?

For compatibility with transmitters using phase modulation
To reduce impulse noise reception
For higher efficiency
To remove third-order distortion products


What does the radio communication term "ray tracing" describe?

The process in which an electronic display presents a pattern
Modeling a radio wave's path through the ionosphere
Determining the radiation pattern from an array of antennas
Evaluating high voltage sources for x-rays


What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

13 Hz
26 Hz
52 Hz
104 Hz


Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Very low power consumption decreases frequency drift
Immunity to out-of-sequence coding reduces spurious responses
Very high speed allows digitizing high frequencies
All these choices are correct


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


What is meant by the blocking dynamic range of a receiver?

The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
The difference in dB between the noise floor and the third-order intercept point
The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor


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 can be measured with a vector network analyzer?

Input impedance
Output impedance
Reflection coefficient
All these choices are correct


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


What type of circuit is shown in Figure E7-2?

Switching voltage regulator
Grounded emitter amplifier
Linear voltage regulator
Monostable multivibrator
Circuit Diagram


Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Provide the crystal with a specified parallel inductance
Provide the crystal with a specified parallel capacitance
Bias the crystal at a specified voltage
Bias the crystal at a specified current


Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

Point 2
Point 4
Point 5
Point 6
Circuit Diagram


For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
Teaching an amateur operator license examination preparation course
No expenses are authorized for reimbursement
Providing amateur operator license examination preparation training materials


What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

An exponential rate of one
One time constant
One exponential period
A time factor of one


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


Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

50 ohms
62 ohms
75 ohms
450 ohms


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 efficiency of a photovoltaic cell?

The output RF power divided by the input DC power
Cost per kilowatt-hour generated
The open-circuit voltage divided by the short-circuit current under full illumination
The relative fraction of light that is converted to current


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

By multiplying the apparent power by 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 by the power factor


What are the two families of circles and arcs that make up a Smith chart?

Resistance and voltage
Reactance and voltage
Resistance and reactance
Voltage and impedance


What logical operation does a NAND gate perform?

It produces logic 0 at its output only when all inputs are logic 0
It produces logic 1 at its output only when all inputs are logic 1
It produces logic 0 at its output if some but not all inputs are logic 1
It produces logic 0 at its output only when all inputs are logic 1


In Figure E6-1, what is the schematic symbol for an N-channel dual-gate MOSFET?

Circuit Diagram


What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Electrolytic capacitors
Butterworth filters
Ferrite beads
Steel-core toroids


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

The jet stream
Temperature inversion
Wind shear
Dust devil


What is meant by the "op-amp input offset voltage"?

The output voltage of the op-amp minus its input voltage
The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
The differential input voltage needed to bring the open loop output voltage to zero
The potential between the amplifier input terminals of the op-amp in an open loop condition


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


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