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

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1. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Only a person named in an amateur station license grant
B	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
C	Only a person with an FCC Marine Radio
D	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	A signal transmitted to prevent its detection by any station other than the intended recipient
B	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
C	An amateur station transmission made at random without the proper call sign identification
D	Any transmitted signal that unintentionally interferes with another licensed radio station

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	The use of a control link between a control point and a locally controlled station
B	The use of devices and procedures for control so that the control operator does not have to be present at a control point
C	A station operating with its output power controlled automatically
D	Remotely controlling a station's antenna pattern through a directional control link

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station so designated by the ITU
B	All of these choices are correct
C	Any amateur station designated by NASA
D	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

5. - E1E12

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

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

6. - E1F12

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only Amateur Extra Class operators
B	Any licensed amateur operator
C	Only Technician, General, Advanced or Amateur Extra Class operators
D	Only General, Advanced or Amateur Extra Class operators

7. - E2A09

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

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

8. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
B	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
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. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send your full call sign and grid square
B	Send the call sign of the DX station three times, the words "this is", then your call sign three times
C	Send only the last two letters of your call sign until you make contact
D	Send your full call sign once or twice

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	Olivia
B	FSK441
C	PACTOR III
D	JT65

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK applies the data signal to the transmitter VFO
B	Direct FSK uses a DC-coupled data connection
C	Audio FSK can be performed anywhere in the transmit chain
D	Audio FSK has a superior frequency response

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

13. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	7500 miles
B	5000 miles
C	1000 miles
D	2500 miles

14. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Waning sunspot numbers
B	Moderate solar wind
C	Very low solar activity
D	An extreme geomagnetic storm

15. - E4A15

What is an advantage of a period-measuring frequency counter over a direct-count type?

Select	Answer
A	It can directly measure the modulation index of an FM transmitter
B	It can run on battery power for remote measurements
C	It provides improved resolution of low-frequency signals within a comparable time period
D	It does not require an expensive high-precision time base

16. - E4B10

Which of the following describes a method to measure intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter with two non-harmonically related audio frequencies and observe the RF output with a spectrum analyzer
B	Modulate the transmitter with two non-harmonically related radio frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a peak reading wattmeter
D	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a logic analyzer

17. - E4C01

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

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

18. - E4D09

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

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

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

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

20. - E5A05

What is the magnitude of the current at the input of a series RLC circuit as the frequency goes through resonance?

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

21. - E5B04

What is the time constant of a circuit having two 220 microfarad capacitors and two 1 megohm resistors, all in parallel?

Select	Answer
A	110 seconds
B	220 seconds
C	55 seconds
D	440 seconds

22. - E5C13

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Elliptical coordinates
B	Maidenhead grid
C	Faraday grid
D	Rectangular coordinates

23. - E5D03

What is microstrip?

Select	Answer
A	Lightweight transmission line made of common zip cord
B	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
C	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
D	Miniature coax used for low power applications

24. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Acceptor impurity
B	Donor impurity
C	N-type impurity
D	Insulator impurity

25. - E6B03

What special type of diode is capable of both amplification and oscillation?

Select	Answer
A	Tunnel
B	Point contact
C	Junction
D	Zener

26. - E6C12

What is BiCMOS logic?

Select	Answer
A	A logic family based on bismuth CMOS devices
B	A FET logic family based on bimetallic semiconductors
C	A logic device with two CMOS circuits per package
D	An integrated circuit logic family using both bipolar and CMOS transistors

27. - E6D05

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

Select	Answer
A	Ferrite toroids generally require fewer turns to produce a given inductance value
B	Ferrite toroids generally have better temperature stability
C	Ferrite toroids generally have lower initial permeability
D	Ferrite toroids are easier to use with surface mount technology

28. - E6E02

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

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

29. - E6F12

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Electrons
B	Photons
C	Protons
D	Holes

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	A flip-flop
B	A clock
C	An "AND" gate
D	An "OR" gate

31. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	Select transistors with high beta
B	All of these choices are correct
C	Use a resistor in series with the emitter
D	Neutralization

32. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It introduces transconductance to cancel the reactive part of impedance
B	Network resistances are substituted for load resistances and reactances are matched to the resistances
C	It introduces negative resistance to cancel the resistive part of impedance
D	It cancels the reactive part of the impedance and changes the resistive part to a desired value

33. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A series regulator
B	A shunt regulator
C	A series current source
D	A shunt current source

34. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	An audio prescaler
B	A heterodyne suppressor
C	A de-emphasis network
D	A pre-emphasis network

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	Reference voltage level and sample width in bits
C	Sample clock phase noise
D	Data storage transfer rate

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	38
C	1
D	76

37. - E7H01

What are three oscillator circuits used in Amateur Radio equipment?

Select	Answer
A	Taft, Pierce and negative feedback
B	Taft, Hartley and Pierce
C	Colpitts, Hartley and Pierce
D	Pierce, Fenner and Beane

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	A method of decimation by randomly skipping samples
D	An abnormal condition where the converter cannot settle on a value to represent the signal

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
B	The ratio of the highest audio modulating frequency to the average audio modulating frequency
C	The ratio of the carrier center frequency to the audio modulating frequency
D	The ratio of the audio modulating frequency to the center carrier frequency

40. - E8C04

What technique is used to minimize the bandwidth requirements of a PSK31 signal?

Select	Answer
A	Zero-sum character encoding
B	Use of trapezoidal data pulses
C	Use of sinusoidal data pulses
D	Reed-Solomon character encoding

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	The receiver is always equipped with a digital blanker
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
D	Signals not using the spread spectrum algorithm are suppressed in the receiver

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	126 watts
C	300 watts
D	317 watts

43. - E9B15

What is the front-to-back ratio of the radiation pattern shown in Figure E9-2?

Select	Answer
A	15 dB
B	28 dB
C	24 dB
D	3 dB

44. - E9C04

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

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

45. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
B	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
C	A 50 ohm resistor connected to ground
D	An electrically short connection to a metal water pipe

46. - E9E12

What is the primary purpose of a phasing line when used with an antenna having multiple driven elements?

Select	Answer
A	It allows single-band antennas to operate on other bands
B	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
C	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
D	It makes sure the antenna has a low-angle radiation pattern

47. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	The surge impedance is higher in a parallel feed line
B	Skin effect is less pronounced in the coaxial cable
C	The characteristic impedance is higher in a parallel feed line
D	Electrical signals move more slowly in a coaxial cable than in air

48. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning prime center with regard to the reactance axis
B	Reassigning reactance values with regard to the resistance axis
C	Reassigning resistance values with regard to the reactance axis
D	Reassigning impedance values with regard to the prime center

49. - E9H04

What is an advantage of using a shielded loop antenna for direction finding?

Select	Answer
A	It is electro statically balanced against ground, giving better nulls
B	It automatically cancels ignition noise in mobile installations
C	It allows stations to communicate without giving away their position
D	It eliminates tracking errors caused by strong out-of-band signals

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	E field and H field radiation intensity peaks can occur at different locations
C	All of these choices are correct
D	The body reacts to electromagnetic radiation from both the E and H fields

Figure E7-4

Figure E9-2