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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	300 Hz above the lower band edge
B	3 kHz above the lower band edge
C	1 kHz above the lower band edge
D	The exact lower band edge

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

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Messages intended for connection to users of the maritime satellite service
B	Communications incidental to the purpose of the amateur service and remarks of a personal nature
C	Business-related messages for non-profit organizations
D	All of these choices are correct

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station located more than 50 km above the Earth's surface
B	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
C	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
D	An amateur station that transmits telemetry consisting of measurements of upper atmosphere

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 74%
B	Minimum passing score of 80%
C	Minimum passing score of 70%
D	Minimum passing score of 77%

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	222 MHz - 223 MHz
B	440 MHz - 450 MHz
C	420 MHz - 430 MHz
D	53 MHz - 54 MHz

7. - E2A08

Why should effective radiated power to a satellite which uses a linear transponder be limited?

Select	Answer
A	To avoid interfering with terrestrial QSOs
B	To prevent creating errors in the satellite telemetry
C	To prevent the satellite from emitting out-of-band signals
D	To avoid reducing the downlink power to all other users

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Turning off the scanning beam while it is traveling from right to left or from bottom to top
B	Turning off the scanning beam at the conclusion of a transmission
C	Synchronization of the horizontal and vertical sync pulses
D	Transmitting a black and white test pattern

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	In the middle of each band, usually on the national calling frequency
B	At the top of each band, usually in a segment reserved for contests
C	In the weak signal segment of the band, with most of the activity near the calling frequency
D	In the middle of the band, usually 25 kHz above the national calling frequency

10. - E2D05

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Digipeating
B	Node hopping
C	Multi-satellite relaying
D	Store-and-forward

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	AMTOR
B	PACTOR
C	RTTY
D	Hellschreiber

12. - E3A05

Tropospheric propagation of microwave signals often occurs along what weather related structure?

Select	Answer
A	Sprites and jets
B	Gray-line
C	Warm and cold fronts
D	Lightning discharges

13. - E3B13

Why is chordal hop propagation desirable?

Select	Answer
A	The signal experiences less loss along the path compared to normal skip propagation
B	Atmospheric noise is lower in the direction of chordal hop propagation
C	Signals travel faster along ionospheric chords
D	The MUF for chordal hop propagation is much lower than for normal skip propagation

14. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	NVIS
B	Polar paths
C	Transequatorial propagation
D	Sporadic-E

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	SWR and frequency
B	SWR and time
C	RF amplitude and time
D	RF amplitude and frequency

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	Short circuit, open circuit, and resonant circuit
C	50 ohms, 75 ohms, and 90 ohms
D	Short circuit, open circuit, and 50 ohms

17. - E4C03

What is the term for the blocking of one FM phone signal by another, stronger FM phone signal?

Select	Answer
A	Cross-modulation interference
B	Frequency discrimination
C	Desensitization
D	Capture effect

18. - E4D13

Which of the following can cause receiver desensitization?

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

19. - E4E02

Which of the following types of receiver noise can often be reduced with a DSP noise filter?

Select	Answer
A	Ignition noise
B	Power line noise
C	Broadband white noise
D	All of these choices are correct

20. - E5A01

What can cause the voltage across reactances in series to be larger than the voltage applied to them?

Select	Answer
A	Conductance
B	Capacitance
C	Resistance
D	Resonance

21. - E5B12

What is admittance?

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

22. - E5C14

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 400 ohm resistor and a 38 picofarad capacitor at 14 MHz?

Select	Answer
A	Point 5
B	Point 4
C	Point 2
D	Point 6

23. - E5D16

What is the power factor of an R-L circuit having a 30 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	1.73
C	0.5
D	0.577

24. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To keep the gate voltage within specifications and prevent the device from overheating
B	To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages
C	To protect the substrate from excessive voltages
D	To provide a voltage reference for the correct amount of reverse-bias gate voltage

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

26. - E6C02

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

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

27. - E6D11

How many turns will be required to produce a 1-mH inductor using a core that has an inductance index (A L) value of 523 millihenrys/1000 turns?

Select	Answer
A	4 turns
B	43 turns
C	2 turns
D	229 turns

28. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	TO-220
B	Axial lead
C	Surface mount
D	Radial lead

29. - E6F07

What is a solid state relay?

Select	Answer
A	A passive delay line
B	A device that uses semiconductors to implement the functions of an electromechanical relay
C	A relay using transistors to drive the relay coil
D	A mechanical relay that latches in the on or off state each time it is pulsed

30. - E7A12

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

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

31. - E7B16

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

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

32. - E7C14

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

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

33. - E7D12

What is the drop-out voltage of an analog voltage regulator?

Select	Answer
A	Minimum input voltage for rated power dissipation
B	Maximum amount that the output voltage may decrease at rated load
C	Minimum input-to-output voltage required to maintain regulation
D	Maximum amount that the output voltage drops when the input voltage is varied over its specified range

34. - E7E11

Which type of detector is used for demodulating SSB signals?

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

35. - E7F15

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters delay all frequency components of the signal by the same amount
B	All of these choices are correct
C	FIR filters are easier to implement for a given set of passband rolloff requirements
D	FIR filters can respond faster to impulses

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	0.03
B	1
C	76
D	38

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

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

38. - E8A05

What would be the most accurate way of measuring the RMS voltage of a complex waveform?

Select	Answer
A	By measuring the heating effect in a known resistor
B	By using a grid dip meter
C	By measuring the voltage with a D'Arsonval meter
D	By using an absorption wave meter

39. - E8B02

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

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

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Baud is twice the symbol rate
B	Symbol rate is only used for packet-based modes
C	They are the same
D	Baud is only used for RTTY

41. - E8D09

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

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

42. - E9A09

How is antenna efficiency calculated?

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

43. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	75 degrees
B	7.5 degrees
C	45 degrees
D	25 degrees

44. - E9C06

What is the effect of a terminating resistor on a rhombic antenna?

Select	Answer
A	It decreases the ground loss
B	It changes the radiation pattern from bidirectional to unidirectional
C	It reflects the standing waves on the antenna elements back to the transmitter
D	It changes the radiation pattern from horizontal to vertical polarization

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Improved radiation efficiency
B	Lower Q
C	Greater structural strength
D	Higher losses

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 delta match
B	The gamma match
C	The stub match
D	The omega match

47. - E9F14

What impedance does a 1/2 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 output impedance of the generator
C	The same as the characteristic impedance of the line
D	Very low impedance

48. - E9G05

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

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

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	A small coil of wire tightly wound around a toroidal ferrite core
B	One or more turns of wire wound in the shape of a large open coil
C	A large circularly polarized antenna
D	A vertical antenna coupled to a feed line through an inductive loop of wire

50. - E0A01

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

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

Figure E5-2

Figure E7-4

Figure E9-2

Figure E9-3