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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	60 meter band
B	17 meter band
C	30 meter band
D	12 meter band

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	10 miles
B	3 miles
C	30 miles
D	1 mile

3. - E1C01

What is a remotely controlled station?

Select	Answer
A	A station controlled indirectly through a control link
B	A station operating under automatic control
C	A station operated away from its regular home location
D	A station controlled by someone other than the licensee

4. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station, subject to the privileges of the class of operator license held by the control operator
B	Only those of Amateur Extra Class operators
C	Only those of General, Advanced or Amateur Extra Class operators
D	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau

5. - E1E02

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

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

6. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When neither the amateur nor his or her employer has a pecuniary interest in the communications
B	When transmitting international third-party communications
C	When the total money involved does not exceed $25
D	When the control operator is employed by the FCC or another government agency

7. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The uplink and downlink frequency ranges
B	The location of the ground control station
C	The polarization of uplink and downlink signals
D	Power limits for uplink and downlink transmissions

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	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	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

9. - E2C12

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Wait 90 minutes or so for the signal degradation to pass
B	Wait 24 hours before attempting another communication on the band
C	Switch to a higher frequency HF band
D	Switch to a lower frequency HF band

10. - E2D02

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

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

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	The mark and space signal have been inverted
B	Selective fading has occurred
C	The receiver has drifted 5 kHz from the desired receive frequency
D	One of the signal filters is saturated

12. - E3A14

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

Select	Answer
A	South
B	East
C	West
D	North

13. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	20 meters
B	6 meters
C	80 meters
D	10 meters

14. - E3C11

What does VOACAP software model?

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

15. - E4A08

Which of the following instrument would be best for measuring the SWR of a beam antenna?

Select	Answer
A	An antenna analyzer
B	A spectrum analyzer
C	A Q meter
D	An ohmmeter

16. - E4B17

What three test loads are used to calibrate a standard RF vector network analyzer?

Select	Answer
A	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
B	50 ohms, 75 ohms, and 90 ohms
C	Short circuit, open circuit, and 50 ohms
D	Short circuit, open circuit, and resonant circuit

17. - E4C01

What is an effect of excessive phase noise in the local oscillator section of a receiver?

Select	Answer
A	It limits the receiver's ability to receive strong signals
B	It decreases receiver third-order intermodulation distortion dynamic range
C	It can cause strong signals on nearby frequencies to interfere with reception of weak signals
D	It reduces receiver sensitivity

18. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
B	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
C	When the signals from the transmitters are reflected in phase from airplanes passing overhead
D	When the signals from the transmitters are reflected out of phase from airplanes passing overhead

19. - E4E10

What is a common characteristic of interference caused by a touch controlled electrical device?

Select	Answer
A	The interfering signal may drift slowly across the HF spectrum
B	All of these choices are correct
C	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band
D	The interfering signal sounds like AC hum on an AM receiver or a carrier modulated by 60 Hz hum on a SSB or CW receiver

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Parasitic effects are minimized
B	Fewer components are needed for the same performance
C	Internal voltages and circulating currents increase
D	Phase shift can become uncontrolled

21. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

Select	Answer
A	14 degrees with the voltage lagging the current
B	76 degrees with the voltage leading the current
C	76 degrees with the voltage lagging the current
D	14 degrees with the voltage leading the current

22. - E5C07

What is a vector?

Select	Answer
A	The inverse of the tangent function
B	The value of a quantity that changes over time
C	A quantity with both magnitude and an angular component
D	The inverse of the sine function

23. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the reactive power by the power factor
B	By multiplying the reactive power times the power factor
C	By dividing the apparent power by the power factor
D	By multiplying the apparent power times the power factor

24. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	Insulated gate
B	Bipolar
C	P-type
D	N-type

25. - E6B09

What is a common use for point contact diodes?

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

26. - E6C02

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

Select	Answer
A	The comparator enters latch-up
B	The comparator changes its output state
C	The IC input can be damaged
D	The feedback loop becomes unstable

27. - E6D14

Which type of slug material decreases inductance when inserted into a coil?

Select	Answer
A	Ferrite
B	Powdered-iron
C	Brass
D	Ceramic

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Surface mount
B	Virtual lead mounting
C	Direct soldering
D	Stripped lead

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A frequency-determining unit for a transmitter or receiver
B	A display that uses a glowing liquid to remain brightly lit in dim light
C	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
D	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied

30. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It maintains a constant output voltage, regardless of variations in the input voltage
B	It stores one bit of data in either a 0 or 1 state
C	It switches momentarily to the opposite binary state and then returns to its original state after a set time
D	It produces a continuous square wave oscillating between 1 and 0

31. - E7B06

Which of the following amplifier types reduces or eliminates even order harmonics?

Select	Answer
A	Push-push
B	Class C
C	Class AB
D	Push-pull

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Lower losses
B	Greater harmonic suppression
C	Greater transformation range
D	Higher efficiency

33. - E7D01

What is one characteristic of a linear electronic voltage regulator?

Select	Answer
A	The conduction of a control element is varied to maintain a constant output voltage
B	It eliminates the need for a pass transistor
C	It has a ramp voltage as its output
D	The control element duty cycle is proportional to the line or load conditions

34. - E7E11

Which type of detector is used for demodulating SSB signals?

Select	Answer
A	Phase detector
B	Product detector
C	Discriminator
D	Phase comparator

35. - E7F10

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

Select	Answer
A	Sample clock phase noise
B	Sample rate
C	Sample width in bits
D	Processor latency

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Restrict both gain and Q
B	Restrict gain but increase Q
C	Increase both gain and Q
D	Restrict Q but increase gain

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through a tapped coil
C	Through a quartz crystal
D	Through link coupling

38. - E8A04

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

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

39. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	High speed digital modes
B	OFDM signals are not allowed on amateur bands
C	Extremely low-power contacts
D	EME

40. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By transmitting extra data that may be used to detect and correct transmission errors
B	By the receiving station repeating each block of three data characters
C	By transmitting a special algorithm to the receiving station along with the data characters
D	By varying the frequency shift of the transmitted signal according to a predefined algorithm

41. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It includes built in error correction features
B	It is possible to transmit both upper and lower case text
C	It contains fewer information bits per character than any other code
D	It uses one character as a shift code to send numeric and special characters

42. - E9A03

Why would one need to know the feed point impedance of an antenna?

Select	Answer
A	To measure the near-field radiation density from a transmitting antenna
B	To match impedances in order to minimize standing wave ratio on the transmission line
C	To calculate the front-to-side ratio of the antenna
D	To calculate the front-to-back ratio of the antenna

43. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	3
B	1
C	7
D	4

44. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The vertical angle increases
B	The front-to-back ratio decreases
C	The lobes become more perpendicular to the wire
D	The lobes align more in the direction of the wire

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

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 omega matching system
B	The gamma matching system
C	The delta matching system
D	The stub matching system

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

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

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

50. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce RF current flow between pieces of equipment
B	Reduce received noise
C	Reduce RFI to telephones and home entertainment systems
D	Lightning protection

Figure E9-2

Figure E9-3