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

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Only those club stations licensed to Amateur Extra class operators
B	Any FCC-licensed amateur station except a Technician class
C	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
D	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served

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	Automatically manipulating local station controls
D	Controlling a repeater using a portable handheld transceiver

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	6 meters and 2 meters
B	6 meters, 2 meters, and 1.25 meters
C	2 meters and 1.25 meters
D	2 meters

5. - E1E05

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

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

6. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications in a language other than English
B	Communications that have a political content, except as allowed by the Fairness Doctrine
C	Communications that have a religious content
D	Communications transmitted for hire or material compensation, except as otherwise provided in the rules

7. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From north to south
B	From east to west
C	From south to north
D	From west to east

8. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	90
B	60
C	30
D	120

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. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It supplies signals to guide the antenna to track the Moon
B	All of these choices are correct
C	It controls the receiver to track Doppler shift
D	It can decode signals many dB below the noise floor using FEC

11. - E2E07

What is the typical bandwidth of a properly modulated MFSK16 signal?

Select	Answer
A	550 Hz
B	31 Hz
C	2.16 kHz
D	316 Hz

12. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Urban areas
B	Bodies of water
C	Mountain ranges
D	Forests

13. - E3B08

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

Select	Answer
A	Sporadic-E
B	Long-path
C	Gray-line
D	Transequatorial

14. - E3C10

What does the 304A solar parameter measure?

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

15. - E4A05

What might be an advantage of a digital vs an analog oscilloscope?

Select	Answer
A	Storage of traces for future reference
B	Automatic amplitude and frequency numerical readout
C	All of these choices are correct
D	Manipulation of time base after trace capture

16. - E4B07

What do the subscripts of S parameters represent?

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

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	Capture effect
C	Frequency discrimination
D	Desensitization

18. - E4D13

Which of the following can cause receiver desensitization?

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

19. - E4E11

Which is the most likely cause if you are hearing combinations of local AM broadcast signals within one or more of the MF or HF ham bands?

Select	Answer
A	You are receiving sky wave signals from a distant station
B	Your station receiver IF amplifier stage is defective
C	The broadcast station is transmitting an over-modulated signal
D	Nearby corroded metal joints are mixing and re-radiating the broadcast signals

20. - E5A09

How is the Q of an RLC parallel resonant circuit calculated?

Select	Answer
A	Reactance of either the inductance or capacitance divided by the resistance
B	Resistance divided by the reactance of either the inductance or capacitance
C	Reactance of either the inductance or capacitance multiplied by the resistance
D	Reactance of the inductance multiplied by the reactance of the capacitance

21. - E5B12

What is admittance?

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

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 6
D	Point 2

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	1.73
C	0.5
D	1.414

24. - E6A13

What do the initials CMOS stand for?

Select	Answer
A	Common Mode Organic Silicon
B	Complementary Mica-Oxide Silicon
C	Common Mode Oscillating System
D	Complementary Metal-Oxide Semiconductor

25. - E6B08

Which of the following describes a type of semiconductor diode?

Select	Answer
A	Metal-semiconductor junction
B	Thermionic emission diode
C	CMOS-field effect
D	Electrolytic rectifier

26. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A programmable collection of logic gates and circuits in a single integrated circuit
B	Programmable equipment used for testing digital logic integrated circuits
C	An algorithm for simulating logic functions during circuit design
D	A device to control industrial equipment

27. - E6D15

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Magnetizing current
B	Direct current
C	Stabilizing current
D	Excitation current

28. - E6E10

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

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

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	An LED and a phototransistor
B	A frequency modulated helium-neon laser
C	An amplitude modulated helium-neon laser
D	A lens and a photomultiplier

30. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic "1" at its output if all inputs are logic "0"
B	It produces logic "0" at its output if all inputs are logic "1"
C	It produces logic "1" at its output if any or all inputs are logic "1"
D	It only produces logic "0" at its output when all inputs are logic "1"

31. - E7B06

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

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

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A filter with narrow bandwidth and steep skirts made using quartz crystals
B	An audio filter made with four quartz crystals that resonate at 1kHz intervals
C	A power supply filter made with interlaced quartz crystals
D	A filter with wide bandwidth and shallow skirts made using quartz crystals

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

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of an amplifier tank circuit to produce AM signals
B	By varying the tuning of an amplifier tank circuit to produce PM signals
C	By varying the tuning of a microphone preamplifier to produce AM signals
D	By varying the tuning of a microphone preamplifier to produce PM signals

35. - E7F11

What sets the minimum detectable signal level for an SDR in the absence of atmospheric or thermal noise?

Select	Answer
A	Missing codes and jitter
B	Data storage transfer rate
C	Reference voltage level and sample width in bits
D	Sample clock phase noise

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 Q but increase gain
C	Restrict gain but increase Q
D	Increase both gain and Q

37. - E7H02

Which describes a microphonic?

Select	Answer
A	Excess loading of the microphone by an oscillator
B	An IC used for amplifying microphone signals
C	Changes in oscillator frequency due to mechanical vibration
D	Distortion caused by RF pickup on the microphone cable

38. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The characteristics of the modulating signal
B	The frequency of the modulating signal
C	The amplifier gain
D	The degree of carrier suppression

39. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	2.14
B	0.214
C	47
D	0.47

40. - E8C05

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

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

41. - E8D06

Which of the following indicates likely overmodulation of an AFSK signal such as PSK or MFSK?

Select	Answer
A	High reflected power
B	Strong ALC action
C	Rapid signal fading
D	Harmonics on higher bands

42. - E9A14

What is meant by the radiation resistance of an antenna?

Select	Answer
A	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
B	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
C	The combined losses of the antenna elements and feed line
D	The specific impedance of the antenna

43. - E9B06

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

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

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It changes the impedance angle of the matching network
B	It reduces losses in the radiating portion of the antenna
C	It reduces low-angle radiation
D	It causes increased SWR

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

Select	Answer
A	It radiates the harmonics and fundamental equally well
B	It must be neutralized
C	It is too sharply directional at lower frequencies
D	It might radiate harmonics

46. - E9E10

Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Select	Answer
A	Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna
B	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
C	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
D	Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable

47. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically one-half wavelength long at 14.10 MHz?

Select	Answer
A	20 meters
B	10 meters
C	71 meters
D	15 meters

48. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Satellite azimuth and elevation bearings
B	Impedance and SWR values in transmission lines
C	Beam headings and radiation patterns
D	Trigonometric functions

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It should be configured as a four-sided loop
B	It should be one or more wavelengths long
C	It must be mounted more than 1 wavelength above ground
D	Its overall length must not exceed 1/4 wavelength

50. - E0A05

What is one of the potential hazards of using microwaves in the amateur radio bands?

Select	Answer
A	Microwaves are ionizing radiation
B	The high gain antennas commonly used can result in high exposure levels
C	Microwaves often travel long distances by ionospheric reflection
D	The extremely high frequency energy can damage the joints of antenna structures

Figure E5-2

Figure E9-2