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 can be done to prevent unwanted oscillations in an RF power amplifier?

Tune the stage for maximum SWR
Tune both the input and output for maximum power
Install parasitic suppressors and/or neutralize the stage
Use a phase inverter in the output filter


In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

75 degrees
50 degrees
25 degrees
30 degrees
Circuit Diagram


What core material property determines the inductance of an inductor?

Thermal impedance


What parameter describes the interactions at the load end of a mismatched transmission line?

Characteristic impedance
Reflection coefficient
Velocity factor
Dielectric constant


How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

They are both low impedance
An FET has lower input impedance
An FET has higher input impedance
They are both high impedance


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


How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Loosely couple the analyzer near the antenna base
Connect the analyzer via a high-impedance transformer to the antenna
Loosely couple the antenna and a dummy load to the analyzer
Connect the antenna feed line directly to the analyzer's connector


What is meant by the term mode? as applied to an amateur radio satellite?

Whether the satellite is in a low earth or geostationary orbit
The satellite's uplink and downlink frequency bands
The satellite's orientation with respect to the Earth
Whether the satellite is in a polar or equatorial orbit


How is power supplied to the most common type of MMIC?

Through a resistor and/or RF choke connected to the amplifier output lead
MMICs require no operating bias
Through a capacitor and RF choke connected to the amplifier input lead
Directly to the bias voltage (VCC IN) lead


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


What does a receiver noise floor of -174 dBm represent?

The minimum detectable signal as a function of receive frequency
The theoretical noise in a 1 Hz bandwidth 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


How many horizontal lines make up a fast-scan (NTSC) television frame?



What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

14 degrees with the voltage lagging the current
14 degrees with the voltage leading the current
76 degrees with the voltage lagging the current
76 degrees with the voltage leading the current


Which type of detector circuit is used for demodulating SSB signals?

Phase detector
Product detector
Phase comparator


How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

200 watts
1000 watts
1600 watts
600 watts


What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

7.0 meters
8.5 meters
10.6 meters
13.3 meters


What current flows equally on all conductors of an unshielded multi-conductor cable?

Differential-mode current
Common-mode current
Reactive current only
Return current


How can the output voltage of a multiple-turn receiving loop antenna be increased?

By reducing the permeability of the loop shield
By utilizing high impedance wire for the coupling loop
By winding adjacent turns in opposing directions
By increasing the number of turns and/or the area


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 the FCC rules
You must submit engineering drawings to the FAA
You must file an Environmental Impact Statement with the EPA before construction begins
You must obtain a construction permit from the airport zoning authority


What device is typically used as a stable voltage reference in a linear voltage regulator?

A Zener diode
A tunnel diode
A varactor diode


Which of the following data are used by the APRS network to communicate station location?

Polar coordinates
Time and frequency
Radio direction finding spectrum analysis
Latitude and longitude


Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

Any amateur station designated by NASA
Any amateur station so designated by the space station licensee
Any amateur station so designated by the ITU
All these choices are correct


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

They are bent toward the magnetic poles
They become depolarized
They become elliptically polarized
They become phase locked


What is used to control the attenuation of RF signals by a PIN diode?

Forward DC bias current
A sub-harmonic pump signal
Reverse voltage larger than the RF signal
Capacitance of an RF coupling capacitor


Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Optoisolators provide a low impedance link between a control circuit and a power circuit
Optoisolators provide impedance matching between the control circuit and power circuit
Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
Optoisolators eliminate the effects of reflected light in the control circuit


Which of the following HF digital modes can be used to transfer binary files?



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?



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


Which of the following methods measures intermodulation distortion in an SSB transmitter?

Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer


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 an operational amplifier?

A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
A digital audio amplifier whose characteristics are determined by components external to the amplifier
An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
A RF amplifier used in the UHF and microwave regions


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

44.72 MHz
22.36 MHz
3.56 MHz
1.78 MHz


What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

Fourier analysis
Vector analysis
Numerical analysis
Differential analysis


What is the relationship between symbol rate and baud?

They are the same
Baud is twice the symbol rate
Symbol rate is only used for packet-based modes
Baud is only used for RTTY


At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

3 dB
6 dB
23 dB
26 dB


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


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


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


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


How may dangerous levels of carbon monoxide from an emergency generator be detected?

By the odor
Only with a carbon monoxide detector
Any ordinary smoke detector can be used
By the yellowish appearance of the gas


Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

Lightning discharges
Warm and cold fronts
Sprites and jets


What type of logic defines "1" as a high voltage?

Reverse Logic
Assertive Logic
Negative logic
Positive Logic


What is the effect of adding a terminating resistor to 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


Which of the following reduces the likelihood of receiver desensitization?

Decrease the RF bandwidth of the receiver
Raise the receiver IF frequency
Increase the receiver front end gain
Switch from fast AGC to slow AGC


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 the Cabrillo format?

A standard for submission of electronic contest logs
A method of exchanging information during a contest QSO
The most common set of contest rules
The rules of order for meetings between contest sponsors


Why does the radio-path horizon distance exceed the geometric horizon?

E-region skip
D-region skip
Due to the Doppler effect
Downward bending due to density variations in the atmosphere


How can an oscillator's microphonic responses be reduced?

Use NP0 capacitors
Reduce noise on the oscillator's power supply
Increase the bias voltage
Mechanically isolate the oscillator circuitry from its enclosure


What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Venn diagram
Near field diagram
Phasor diagram
Far field diagram


In Figure E6-3, what is the schematic symbol for a NOR gate?

Circuit Diagram