US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
B	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
C	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
D	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	1.0
B	2.0
C	0.5
D	3.0

3. - E1C07

What is meant by local control?

Select	Answer
A	Controlling a station through a local auxiliary link
B	Direct manipulation of the transmitter by a control operator
C	Controlling a repeater using a portable handheld transceiver
D	Automatically manipulating local station controls

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
B	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
C	All HF bands
D	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands

5. - E1E02

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

Select	Answer
A	In FCC Part 97
B	In a question pool maintained by all the VECs
C	In a question pool maintained by the FCC
D	In the appropriate FCC Report and Order

6. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must be capable of external RF switching between its input and output networks
B	It must exhibit a gain of 0 dB or less over its full output range
C	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
D	It must produce full legal output when driven by not more than 5 watts of mean RF input power

7. - E2A14

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

Select	Answer
A	APRS
B	Doppler shift of beacon signals
C	Radar
D	Bandwidth compressed LORAN

8. - E2B06

What is vestigial sideband modulation?

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

9. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	30 m
B	2 m
C	6 m
D	33 cm

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	Use of high speed CW or digital modes
B	15 second timed transmission sequences with stations alternating based on location
C	Short transmission with rapidly repeated call signs and signal reports
D	All of these choices are correct

11. - E2E03

How is the timing of JT65 contacts organized?

Select	Answer
A	Alternating transmissions at 1 minute intervals
B	It depends on the lunar phase
C	Stations take turns on alternate days
D	By exchanging ACK/NAK packets

12. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The F1 layer
B	The D layer
C	The E layer
D	The F2 layer

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

Select	Answer
A	Independent waves created in the ionosphere that are elliptically polarized
B	Refracted rays and reflected waves
C	Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances
D	Long path and short path waves

14. - E3C14

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

Select	Answer
A	D-region skip
B	Downward bending due to density variations in the atmosphere
C	E-region skip
D	Downward bending due to aurora refraction

15. - E4A04

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

Select	Answer
A	Analog-to-digital conversion speed of the soundcard
B	Q of the interface of the interface circuit
C	All of these choices are correct
D	Amount of memory on the soundcard

16. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Time base accuracy
B	Input attenuator accuracy
C	Decade divider accuracy
D	Temperature coefficient of the logic

17. - E4C04

How is the noise figure of a receiver defined?

Select	Answer
A	The ratio of thermal noise to atmospheric noise
B	The ratio of atmospheric noise to phase noise
C	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
D	The ratio of the noise bandwidth in Hertz to the theoretical bandwidth of a resistive network

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Audio gain adjusted too low
B	Strong adjacent channel signals
C	Squelch gain misadjusted
D	Audio bias adjusted too high

19. - E4E07

How can you determine if line noise interference is being generated within your home?

Select	Answer
A	By checking the power line voltage with a time domain reflectometer
B	By turning off the AC power line main circuit breaker and listening on a battery operated radio
C	By observing the AC power line voltage with a spectrum analyzer
D	By observing the AC power line waveform with an oscilloscope

20. - E5A11

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	47.3 kHz
B	315.6 Hz
C	23.67 kHz
D	157.8 Hz

21. - E5B12

What is admittance?

Select	Answer
A	The unit used for Q factor
B	The term for the gain of a field effect transistor
C	The turns ratio of a transformer
D	The inverse of impedance

22. - E5C01

Which of the following represents a capacitive reactance in rectangular notation?

Select	Answer
A	-jX
B	X
C	+jX
D	Omega

23. - E5D18

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

Select	Answer
A	704 W
B	1.42 mW
C	355 W
D	252 W

24. - E6A01

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

Select	Answer
A	In high-power audio circuits
B	In high-current rectifier circuits
C	In microwave circuits
D	In very low frequency RF circuits

25. - E6B12

What is one common use for PIN diodes?

Select	Answer
A	As a constant voltage source
B	As a constant current source
C	As an RF switch
D	As a high voltage rectifier

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	2
B	3
C	1
D	4

27. - E6D17

Why should core saturation of a conventional impedance matching transformer be avoided?

Select	Answer
A	Temporary changes of the core permeability could result
B	Magnetic flux would increase with frequency
C	Harmonics and distortion could result
D	RF susceptance would increase

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon nitride
B	Silicon
C	Gallium nitride
D	Silicon dioxide

29. - E6F02

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

Select	Answer
A	It becomes unstable
B	It increases
C	It decreases
D	It stays the same

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It produces ten output pulses for every input pulse
B	It decodes a decimal number for display on a seven segment LED display
C	It produces one output pulse for every ten input pulses
D	It adds two decimal numbers together

31. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

Select	Answer
A	Low efficiency
B	Creation of parasitic oscillations
C	Transmission of spurious signals
D	All of these choices are correct

32. - E7C08

Which of the following factors has the greatest effect in helping determine the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The gain of the RF stage preceding the filter
B	The DC voltage applied to the quartz crystal
C	The amplitude of the signals passing through the filter
D	The relative frequencies of the individual crystals

33. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A constant current source
B	A shunt regulator
C	A series regulator
D	A shunt current source

34. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Spurious mixer products are generated
B	Mixer blanking occurs
C	Automatic limiting occurs
D	A beat frequency is generated

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Interpolate by a factor of three, then decimate by a factor of four
B	Change the gain by a factor of 3/4
C	Multiply each sample value by a factor of 3/4
D	Add 3 to each input value and subtract 4 from each output value

36. - E7G03

What is the typical input impedance of an integrated circuit op-amp?

Select	Answer
A	Very high
B	1000 ohms
C	100 ohms
D	Very low

37. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit also known as a monostable multivibrator
B	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
C	An electronic circuit consisting of a precision push-pull amplifier with a differential input
D	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator

38. - E8A11

What type of information can be conveyed using digital waveforms?

Select	Answer
A	Video signals
B	Human speech
C	All of these choices are correct
D	Data

39. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)?

Select	Answer
A	It increases as the RF carrier frequency increases
B	It does not depend on the RF carrier frequency
C	It decreases as the RF carrier frequency increases
D	It varies with the square root of the RF carrier frequency

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 26 Hz
B	Approximately 104 Hz
C	Approximately 52 Hz
D	Approximately 13 Hz

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	Signals not using the spread spectrum algorithm are suppressed in the receiver
B	The receiver is always equipped with a digital blanker
C	If interference is detected by the receiver it will signal the transmitter to change frequencies
D	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolate the coax shield from ground
B	Reduce the diameter of the radiating element
C	Install a good radial system
D	Shorten the radiating element

43. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	36 dB
B	18 dB
C	24 dB
D	14 dB

44. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

Select	Answer
A	The main lobe takeoff angle increases in the downhill direction
B	The horizontal beam width decreases in the downhill direction
C	The horizontal beam width increases in the uphill direction
D	The main lobe takeoff angle decreases in the downhill direction

45. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
B	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
C	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
D	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase

46. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The omega match
B	The delta match
C	The stub match
D	The gamma match

47. - E9F13

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

Select	Answer
A	The same as the characteristic impedance of the transmission line
B	The same as the generator output impedance
C	Very low impedance
D	Very high impedance

48. - E9G05

What type of chart is shown in Figure E9-3?

Select	Answer
A	Azimuth angle radiation pattern chart
B	Smith chart
C	Elevation angle radiation pattern chart
D	Free space radiation directivity chart

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	Atmospheric noise is so high that gain over a dipole is not important
B	They must be erected at least 1/2 wavelength above the ground to attain good directivity
C	Low loss coax transmission line is essential for good performance
D	All of these choices are correct

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Make sure signals from your station are less than the uncontrolled MPE limits
B	Make sure signals from your station are less than the controlled MPE limits
C	You need only evaluate exposure levels on your own property
D	Advise your neighbors of the results of your tests

Figure E6-5

Figure E9-1

Figure E9-3