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

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

3. - E1C07

What is meant by local control?

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

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station designated by NASA
B	Any amateur station so designated by the ITU
C	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
D	All of these choices are correct

5. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and submit the documents to the coordinating VEC for grading
B	They must collect and send the documents to the NCVEC for grading
C	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
D	They must collect and send the documents to the FCC according to instructions

6. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To allow regular operation on Land Mobile channels
B	To provide additional spectrum for personal use
C	To provide for experimental amateur communications
D	To provide temporary operation while awaiting normal licensing

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	The 2 meter and 70 centimeter bands
B	Which sideband to use
C	FM and Digital Store-and-Forward systems
D	The 23 centimeter and 13 centimeter bands

8. - E2B06

What is vestigial sideband modulation?

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

9. - E2C02

Which of the following best describes the term self-spotting in regards to HF contest operating?

Select	Answer
A	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
B	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
C	The generally prohibited practice of posting one's own call sign and frequency on a spotting network
D	The acceptable practice of manually posting the call signs of stations on a spotting network

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. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	Pulse modulation
B	Spread spectrum
C	DTMF tones modulating an FM signal
D	FSK

12. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by Moon bounce?

Select	Answer
A	12,000 miles, if the Moon is visible by both stations
B	2000 miles, if the Moon is at apogee
C	500 miles, if the Moon is at perigee
D	5000 miles, if the Moon is at perigee

13. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	160 meters to 40 meters
B	30 meters to 10 meters
C	160 meters to 10 meters
D	6 meters to 2 meters

14. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The ratio of X-Ray flux to radio flux, correlated to sunspot number
B	The solar emission at 304 GHz, correlated to X-Ray flare levels
C	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity
D	UV emissions at 304 angstroms, correlated to solar flux index

15. - E4A01

Which of the following parameter determines the bandwidth of a digital or computer-based oscilloscope?

Select	Answer
A	Input capacitance
B	Sampling rate
C	Input impedance
D	Sample resolution

16. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	Relative quality of the data
B	Frequency order of the measurements
C	The relative time between measurements
D	The port or ports at which measurements are made

17. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and which uses a 455 kHz IF frequency?

Select	Answer
A	13.845 MHz
B	14.755 MHz
C	14.445 MHz
D	15.210 MHz

18. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	A pair of 40 dBm signals will theoretically generate a third-order intermodulation product with the same level as the input signals
B	Signals less than 40 dBm will not generate audible third-order intermodulation products
C	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
D	A pair of 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing a noise suppression resistor and a blocking capacitor in both leads
B	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
C	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
D	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead

20. - E5A07

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

Select	Answer
A	L/R
B	R/L
C	Maximum
D	Minimum

21. - E5B03

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

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

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 8
B	Point 1
C	Point 7
D	Point 3

23. - E5D13

How much power is consumed in a circuit consisting of a 100 ohm resistor in series with a 100 ohm inductive reactance drawing 1 ampere?

Select	Answer
A	200 Watts
B	141.4 Watts
C	100 Watts
D	70.7 Watts

24. - E6A11

In Figure E6-2, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	6
B	1
C	3
D	2

25. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A constant voltage drop under conditions of varying current
B	A negative resistance region
C	An internal capacitance that varies with the applied voltage
D	A constant current drop under conditions of varying voltage

26. - E6C10

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

Select	Answer
A	4
B	3
C	2
D	1

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

28. - E6E03

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

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

29. - E6F02

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

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

30. - E7A12

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

Select	Answer
A	Reverse Logic
B	Negative logic
C	Positive Logic
D	Assertive Logic

31. - E7B02

What is a Class D amplifier?

Select	Answer
A	A type of amplifier that uses switching technology to achieve high efficiency
B	A low power amplifier that uses a differential amplifier for improved linearity
C	A frequency doubling amplifier
D	An amplifier that uses drift-mode FETs for high efficiency

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	The Q of Pi-networks can be varied depending on the component values chosen
B	L-networks cannot perform impedance transformation
C	Pi-networks have fewer components
D	Pi-networks are designed for balanced input and output

33. - E7D10

What is the primary reason that a high-frequency switching type high voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The inverter design does not require any output filtering
B	It uses a diode bridge rectifier for increased output
C	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
D	It uses a large power factor compensation capacitor to create free power from the unused portion of the AC cycle

34. - E7E09

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

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

35. - E7F12

What digital process is applied to I and Q signals in order to recover the baseband modulation information?

Select	Answer
A	Signal conditioning
B	Fast Fourier Transform
C	Decimation
D	Quadrature mixing

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As a high-pass filter used to block RFI at the input to receivers
B	For smoothing power supply output
C	As an audio filter in a receiver
D	As a low-pass filter used between a transmitter and a transmission line

37. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	All of these choices are correct
B	Use a GPS signal reference
C	Use a rubidium stabilized reference oscillator
D	Use a temperature-controlled high Q dielectric resonator

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	An error caused by irregular quantization step size
B	A small amount of noise added to the input signal to allow more precise representation of a signal over time
C	An abnormal condition where the converter cannot settle on a value to represent the signal
D	A method of decimation by randomly skipping samples

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

40. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	4.8 kHz
B	5.76 kHz
C	9.6 kHz
D	15.36 kHz

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

Select	Answer
A	-30 dB
B	+15 dB
C	-20 dB
D	+10 dB

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(total resistance / radiation resistance) x 100 per cent
B	(radiation resistance / transmission resistance) x 100 per cent
C	(radiation resistance / total resistance) x 100 per cent
D	(effective radiated power / transmitter output) x 100 percent

43. - E9B02

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

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

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A type of ground-plane antenna
B	A dipole one-quarter wavelength long
C	A dipole configured to provide forward gain
D	A dipole consisting of one wavelength of wire forming a very thin loop

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The frequency response is widened over the whole frequency band
B	The front-to-back ratio decreases
C	The front-to-back ratio increases
D	The SWR is reduced

46. - E9E11

What is an effective way of matching a feed line to a VHF or UHF antenna when the impedances of both the antenna and feed line are unknown?

Select	Answer
A	Use the universal stub matching technique
B	Connect a parallel-resonant LC network across the antenna feed terminals
C	Use a 50 ohm 1:1 balun between the antenna and feed line
D	Connect a series-resonant LC network across the antenna feed terminals

47. - E9F11

What impedance does a 1/8 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	The same as the characteristic impedance of the line
B	A capacitive reactance
C	An inductive reactance
D	The same as the input impedance of the final generator stage

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The resistance axis
B	The voltage axis
C	The reactance axis
D	The current axis

49. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It increases the sensitivity of a DF antenna array
B	It allows DF antennas to receive signals at different vertical angles
C	It modifies the pattern of a DF antenna array to provide a null in one direction
D	It provides diversity reception that cancels multipath signals

50. - E0A07

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

Select	Answer
A	Any ordinary smoke detector can be used
B	By the odor
C	Only with a carbon monoxide detector
D	By the yellowish appearance of the gas

Figure E5-2

Figure E6-2

Figure E6-5

Figure E9-1

Figure E9-3