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 difference between direct FSK and audio FSK?

Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
Direct FSK occupies less bandwidth
Direct FSK can transmit faster baud rates
Only direct FSK can be decoded by computer


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


Which is the most common input and output impedance of circuits that use MMICs?

50 ohms
300 ohms
450 ohms
10 ohms


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 point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

Point 1
Point 3
Point 7
Point 8
Circuit Diagram


Why is it important to keep lead lengths short for components used in circuits for VHF and above?

To increase the thermal time constant
To avoid unwanted inductive reactance
To maintain component lifetime
All these choices are correct


What is the purpose of the series capacitor in a gamma-type antenna matching network?

To provide DC isolation between the feed line and the antenna
To cancel the inductive reactance of the matching network
To provide a rejection notch that prevents the radiation of harmonics
To transform the antenna impedance to a higher value


Which of these functions can be performed by a phase-locked loop?

Wide-band AF and RF power amplification
Comparison of two digital input signals, digital pulse counter
Photovoltaic conversion, optical coupling
Frequency synthesis, FM demodulation


What is the National Radio Quiet Zone?

An area in Puerto Rico surrounding the Arecibo Radio Telescope
An area in New Mexico surrounding the White Sands Test Area
An area surrounding the National Radio Astronomy Observatory
An area in Florida surrounding Cape Canaveral


Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

A Phase Inverter Load network
A Pi-network with an additional series inductor on the output
A network with only three discrete parts
A matching network in which all components are isolated from ground


Why can an attenuator be used to reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?

The attenuator has a low-pass filter to increase the strength of lower frequency signals
The attenuator has a noise filter to suppress interference
Signals are attenuated separately from the noise
Atmospheric noise is generally greater than internally generated noise even after attenuation


What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Polychlorinated biphenyls
Polymorphic silicon


What happens to the conductivity of a photoconductive material when light shines on it?

It increases
It decreases
It stays the same
It becomes unstable


Which of the following descriptors indicates the greatest solar flare intensity?

Class A
Class B
Class M
Class X


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 is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

A figure-8 end-fire along the axis of the array
A figure-8 broadside to the axis of the array


What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Sample rate
Sample width in bits
Sample clock phase noise
Processor latency


What factors affect the bandwidth of a transmitted CW signal?

IF bandwidth and Q
Modulation index and output power
Keying speed and shape factor (rise and fall time)
All these choices are correct


What is vestigial sideband modulation?

Amplitude modulation in which one complete sideband and a portion of the other are transmitted
A type of modulation in which one sideband is inverted
Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation


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 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


What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

Amplifier desensitization
Adjacent channel interference


What is a common cause of overmodulation of AFSK signals?

Excessive numbers of retries
Ground loops
Bit errors in the modem
Excessive transmit audio levels


What is the magnitude of the impedance of a parallel RLC circuit at resonance?

Approximately equal to circuit resistance
Approximately equal to inductive reactance
Low compared to the circuit resistance
High compared to the circuit resistance


What is the purpose of Q1 in the circuit shown in Figure E7-2?

It provides negative feedback to improve regulation
It provides a constant load for the voltage source
It controls the current supplied to the load
It provides D1 with current
Circuit Diagram


When scheduling EME contacts, which of these conditions will generally result in the least path loss?

When the moon is at perigee
When the moon is full
When the moon is at apogee
When the MUF is above 30 MHz


What characteristic of a PIN diode makes it useful as an RF switch?

Extremely high reverse breakdown voltage
Ability to dissipate large amounts of power
Reverse bias controls its forward voltage drop
Low junction capacitance


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 modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?



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

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 these choices are correct


What digital protocol is used by APRS?



What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

0.23 volts
2.3 volts
-0.23 volts
-2.3 volts
Circuit Diagram


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 function of a DX QSL Manager?

To allocate frequencies for DXpeditions
To handle the receiving and sending of confirmation cards for a DX station
To run a net to allow many stations to contact a rare DX station
To relay calls to and from a DX station


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



Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

CEPT agreement
IARP agreement
ITU reciprocal license
All these choices are correct


What is the radiation resistance of an antenna?

The combined losses of the antenna elements and feed line
The specific impedance of the antenna
The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal


Which of the following can be calculated using a Smith chart?

Impedance along transmission lines
Radiation resistance
Antenna radiation pattern
Radio propagation


What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

A false, jittery low-frequency version of the signal is displayed
All signals will have a DC offset
Calibration of the vertical scale is no longer valid
Excessive blanking occurs, which prevents display of the signal


What may be the penalty for a VE who fraudulently administers or certifies an examination?

Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
A fine of up to $1000 per occurrence
A sentence of up to one year in prison
All these choices are correct


What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Corner frequency
Alpha rejection frequency
Beta cutoff frequency
Alpha cutoff frequency


What impedance does a 1/8-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
An inductive reactance
A capacitive reactance


What is the relationship between the AC current through an inductor and the voltage across an inductor?

Voltage leads current by 90 degrees
Current leads voltage by 90 degrees
Voltage and current are 180 degrees out of phase
Voltage and current are in phase


What happens when the level of a comparator's input signal crosses the threshold?

The IC input can be damaged
The comparator changes its output state
The comparator enters latch-up
The feedback loop becomes unstable


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


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

Class C
Class AB


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 type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

A linearly polarized antenna
A circularly polarized antenna
An isotropic antenna
A log-periodic dipole array


What core material property determines the inductance of an inductor?

Thermal impedance


Which of the following can cause shielded cables to radiate or receive interference?

Low inductance ground connections at both ends of the shield
Common-mode currents on the shield and conductors
Use of braided shielding material
Tying all ground connections to a common point resulting in differential-mode currents in the shield