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

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1. - E1A06

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

Select	Answer
A	At the lowest frequency of the channel
B	At the center frequency of the channel
C	At the highest frequency of the channel
D	On any frequency where the signal's sidebands are within the channel

2. - E1B06

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?

Select	Answer
A	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of FCC rules
B	You must obtain a construction permit from the airport zoning authority
C	You must file an Environmental Impact Statement with the EPA before construction begins
D	No special rules apply if your antenna structure will be less than 300 feet in height

3. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	30 seconds
B	10 minutes
C	3 minutes
D	5 minutes

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

5. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Send the application form to the FCC and inform the FCC of the grade
B	Maintain the application form with the VEC's records
C	Return the application document to the examinee
D	Destroy the application form

6. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the Government of Canada?

Select	Answer
A	All privileges of the Extra Class license
B	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Extra Class privileges
C	Full privileges, up to and including those of the Extra Class License, on the 80, 40, 20, 15, and 10 meter bands
D	None, they must obtain a U.S. license

7. - E2A04

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

Select	Answer
A	Whether the satellite is in a polar or equatorial orbit
B	The satellite's orientation with respect to the Earth
C	The satellite's uplink and downlink frequency bands
D	The type of signals that can be relayed through the satellite

8. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Hue
B	Luminance
C	Spectral Intensity
D	Chroma

9. - E2C10

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

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

10. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with a GPS unit can automatically transmit information to show a mobile station's position during the event
B	All of these choices are correct
C	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
D	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital

11. - E2E03

How is the timing of JT65 contacts organized?

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

12. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Probability of tropospheric propagation
B	Likelihood of rain-scatter along cold or warm fronts
C	Locations of auroral reflecting zones
D	Sporadic E propagation

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
B	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
C	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
D	In darkness, solar absorption drops greatly while atmospheric ionization remains steady

14. - E3C11

What does VOACAP software model?

Select	Answer
A	VHF radio propagation
B	AC voltage and impedance
C	HF propagation
D	AC current and impedance

15. - E4A12

Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

Select	Answer
A	Use high quality double shielded coaxial cables to reduce signal losses
B	All of these choices are correct
C	Attenuate the transmitter output going to the spectrum analyzer
D	Match the antenna to the load

16. - E4B08

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

Select	Answer
A	High reluctance input
B	High impedance input
C	Low reluctance input
D	Low impedance input

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The reference voltage of the analog-to-digital converter
B	One-half the maximum sample rate
C	One-half the maximum sampling buffer size
D	The maximum count value of the analog-to-digital converter

18. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To increase rejection of unwanted signals
B	To allow selection of the optimum RF amplifier device
C	To store often-used frequencies
D	To provide a range of AGC time constants

19. - E4E12

What is one disadvantage of using some types of automatic DSP notch-filters when attempting to copy CW signals?

Select	Answer
A	Received CW signals will appear to be modulated at the DSP clock frequency
B	Any nearby signal passing through the DSP system will overwhelm the desired signal
C	A DSP filter can remove the desired signal at the same time as it removes interfering signals
D	Ringing in the DSP filter will completely remove the spaces between the CW characters

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching bandwidth is increased
B	Matching range is increased
C	It has no effect on impedance matching
D	Matching bandwidth is decreased

21. - E5B05

What happens to the magnitude of a reactance when it is converted to a susceptance?

Select	Answer
A	It is unchanged
B	The sign is reversed
C	The magnitude of the susceptance is the reciprocal of the magnitude of the reactance
D	It is shifted by 90 degrees

22. - E5C17

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor, a 0.64-microhenry inductor and an 85-picofarad capacitor at 24.900 MHz?

Select	Answer
A	Point 8
B	Point 1
C	Point 3
D	Point 5

23. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
B	Thermal effects on the surface of the conductor decrease the impedance
C	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
D	Thermal effects on the surface of the conductor increase the impedance

24. - E6A14

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

Select	Answer
A	They are both high impedance
B	An FET has high input impedance; a bipolar transistor has low input impedance
C	They are both low impedance
D	An FET has low input impedance; a bipolar transistor has high input impedance

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Much higher reverse voltage breakdown
B	Less forward voltage drop
C	Controlled reverse avalanche voltage
D	Enhanced carrier retention time

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	Low power consumption
B	More efficient arithmetic operations
C	High speed operation
D	Ability to connect many device outputs to a common bus

27. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores generally have greater initial permeability
B	Powdered-iron cores generally maintain their characteristics at higher currents
C	Powdered-iron cores generally require fewer turns to produce a given inductance
D	Powdered-iron cores use smaller diameter wire for the same inductance

28. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	PLCC
B	Ball grid array
C	SOT
D	DIP

29. - E6F11

What is the approximate open-circuit voltage produced by a fully-illuminated silicon photovoltaic cell?

Select	Answer
A	0.5 V
B	1.5 V
C	0.1 V
D	12 V

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "0" at its output only when all inputs are logic "0"
B	It produces logic "0" at its output only when all inputs are logic "1"
C	It produces logic "0" at its output if some but not all inputs are logic "1"
D	It produces logic "1" at its output only when all inputs are logic "1"

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

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

32. - E7C14

Which mode is most affected by non-linear phase response in a receiver IF filter?

Select	Answer
A	Video
B	Single-Sideband voice
C	Digital
D	Meteor scatter

33. - E7D11

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

Select	Answer
A	Reference voltage
B	Pass transistor
C	Error amplifier
D	Switching inductance

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	1.414 and 0.707 times the input frequency
B	The sum, difference and square root of the input frequencies
C	The two input frequencies along with their sum and difference frequencies
D	Two and four times the original frequency

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Removing unnecessary significant digits
B	Converting data to binary code decimal form
C	Attenuating the signal
D	Reducing the effective sample rate by removing samples

36. - E7G01

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

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

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a tapped coil
B	Through a neutralizing capacitor
C	Through a capacitive divider
D	Through link coupling

38. - E8A01

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

Select	Answer
A	Fourier analysis
B	Vector analysis
C	Numerical analysis
D	Differential analysis

39. - E8B04

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?

Select	Answer
A	6000
B	3
C	2000
D	1/3

40. - E8C05

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

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

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Increase keying waveform rise and fall times
B	High-pass filters at the transmitter output
C	Low-pass filters at the transmitter output
D	Reduce keying waveform rise and fall times

42. - E9A16

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?

Select	Answer
A	2000 watts
B	300 watts
C	317 watts
D	126 watts

43. - E9B12

What is the far field of an antenna?

Select	Answer
A	The region where radiated power dissipates over a specified time period
B	The region of the ionosphere where radiated power is not refracted
C	The region where radiated field strengths are obstructed by objects of reflection
D	The region where the shape of the antenna pattern is independent of distance

44. - E9C15

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

Select	Answer
A	The main lobe takeoff angle decreases with increasing height
B	The horizontal beam width decreases with height
C	The main lobe takeoff angle increases with increasing height
D	The horizontal beam width increases with height

45. - E9D10

What happens to feed point impedance at the base of a fixed length HF mobile antenna as the frequency of operation is lowered?

Select	Answer
A	The radiation resistance increases and the capacitive reactance increases
B	The radiation resistance decreases and the capacitive reactance decreases
C	The radiation resistance decreases and the capacitive reactance increases
D	The radiation resistance increases and the capacitive reactance decreases

46. - E9E01

What system matches a higher impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The stub matching system
B	The gamma matching system
C	The omega matching system
D	The delta matching system

47. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower velocity factor
B	Lower loss
C	Higher SWR
D	Smaller reflection coefficient

48. - E9G05

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

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

49. - E9H02

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

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

50. - E0A06

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

Select	Answer
A	Ground reflections and scattering make the field impedance vary with location
B	All of these choices are correct
C	E field and H field radiation intensity peaks can occur at different locations
D	The body reacts to electromagnetic radiation from both the E and H fields

Figure E5-2

Figure E9-3