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!


Which of these methods is commonly used to convert analog signals to digital signals?

Sequential sampling
Harmonic regeneration
Level shifting
Phase reversal


What circuit element is controlled by a series analog voltage regulator to maintain a constant output voltage?

Reference voltage
Switching inductance
Error amplifier
Pass transistor


What is a disadvantage of using a multiband trapped antenna?

It might radiate harmonics
It radiates the harmonics and fundamental equally well
It is too sharply directional at lower frequencies
It must be neutralized


How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

704 W
355 W
252 W
1.42 mW


What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

The amateur station must cease operation
The amateur station must cease operation on all frequencies below 30 MHz
The amateur station must cease operation on all frequencies above 30 MHz
The amateur station must avoid transmitting during certain hours on frequencies that cause the interference


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


Which of the following conditions apply when transmitting spread spectrum emission?

A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
The transmission must not be used to obscure the meaning of any communication
All of these choices are correct


With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Yes, the DX station initiated the contact
Yes, the displayed frequency is within the 80 meter CW band segment
No, one of the sidebands of the CW signal will be out of the band
No, U.S. stations are not permitted to use CW emissions below 3.525 MHz


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

Circuit Diagram


What is the triangulation method of direction finding?

The geometric angles of sky waves from the source are used to determine its position
A fixed receiving station plots three headings to the signal source
Antenna headings from several different receiving locations are used to locate the signal source
A fixed receiving station uses three different antennas to plot the location of the signal source


What type of logic defines "0" as a high voltage?

Reverse Logic
Assertive Logic
Negative logic
Positive Logic


Where are the questions for all written U.S. amateur license examinations listed?

In FCC Part 97
In a question pool maintained by the FCC
In a question pool maintained by all the VECs
In the appropriate FCC Report and Order


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 does the impedance 50-j25 represent?

50 ohms resistance in series with 25 ohms inductive reactance
50 ohms resistance in series with 25 ohms capacitive reactance
25 ohms resistance in series with 50 ohms inductive reactance
25 ohms resistance in series with 50 ohms capacitive reactance


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


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

They are bent toward the magnetic poles
Their polarization is randomly modified
They become elliptically polarized
They become phase-locked


What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Bandwidth compressed LORAN
Doppler shift of beacon signals


Which of these materials is affected the most by photoconductivity?

A crystalline semiconductor
An ordinary metal
A heavy metal
A liquid semiconductor


What is meant by circularly polarized electromagnetic waves?

Waves with an electric field bent into a circular shape
Waves with a rotating electric field
Waves that circle the Earth
Waves produced by a loop antenna


Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

Loss of sensitivity
Excess output level


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

The same as the characteristic impedance of the line
The same as the input impedance to the generator
Very high impedance
Very low impedance


How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output


Which of the following semiconductor materials contains excess free electrons?

Insulated gate


By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

By approximately 15 percent of the distance
By approximately twice the distance
By approximately 50 percent of the distance
By approximately four times the distance


Which of the following displays multiple digital signal states simultaneously?

Network analyzer
Bit error rate tester
Modulation monitor
Logic analyzer


Which of the following digital modes is especially useful for EME communications?



What types of communications may be transmitted to amateur stations in foreign countries?

Business-related messages for non-profit organizations
Messages intended for connection to users of the maritime satellite service
Communications incidental to the purpose of the amateur service and remarks of a personal nature
All of these choices are correct


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


How many lines are commonly used in each frame of an amateur slow-scan color television picture?

30 or 60
60 or 100
128 or 256
180 or 360


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 phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

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


What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?



What is a telecommand station in the amateur satellite service?

An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
An amateur station that transmits communications to initiate, modify or terminate functions of a space station
An amateur station located more than 50 km above the Earth's surface
An amateur station that transmits telemetry consisting of measurements of the upper atmosphere


What is one way a single-sideband phone signal can be generated?

By using a balanced modulator followed by a filter
By using a reactance modulator followed by a mixer
By using a loop modulator followed by a mixer
By driving a product detector with a DSB signal


What is a disadvantage of decreasing the number of wire segments in an antenna model below the guideline of 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


During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

At the top of each band, usually in a segment reserved for contests
In the middle of each band, usually on the national calling frequency
In the weak signal segment of the band, with most of the activity near the calling frequency
In the middle of the band, usually 25 kHz above the national calling frequency


What is the primary purpose of a phasing line 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 makes sure the antenna has a low-angle radiation pattern


In Figure E6-5, what is the schematic symbol for a NOR gate?

Circuit Diagram


What is the necessary bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

0.1 Hz
0.3 kHz
0.5 kHz
1.0 kHz


What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

Circuit Diagram


Which of the following is a characteristic of a good DC voltmeter?

High reluctance input
Low reluctance input
High impedance input
Low impedance input


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


What core material property determines the inductance of a toroidal inductor?

Thermal impedance


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 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 major cause of atmospheric static?

Solar radio frequency emissions
Geomagnetic storms
Meteor showers


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


How is positive feedback supplied in a Hartley oscillator?

Through a tapped coil
Through a capacitive divider
Through link coupling
Through a neutralizing capacitor


Why are switching amplifiers more efficient than linear amplifiers?

Switching amplifiers operate at higher voltages
The power transistor is at saturation or cut off most of the time, resulting in low power dissipation
Linear amplifiers have high gain resulting in higher harmonic content
Switching amplifiers use push-pull circuits


How is the timing of JT65 contacts organized?

By exchanging ACK/NAK packets
Stations take turns on alternate days
Alternating transmissions at 1 minute intervals
It depends on the lunar phase