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

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 63 dB below
B	At least 73 dB below
C	At least 43 dB below
D	At least 53 dB below

3. - E1C10

What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Select	Answer
A	Only beacon, repeater or space stations
B	Only earth stations, repeater stations or model craft
C	Only auxiliary, beacon or space stations
D	Only auxiliary, repeater or space stations

4. - E1D02

What is the amateur satellite service?

Select	Answer
A	A spacecraft launching service for amateur-built satellites
B	A radio communications service using amateur radio stations on satellites
C	A radio navigation service using satellites for the purpose of self training, intercommunication and technical studies carried out by amateurs
D	A radio communications service using stations on Earth satellites for public service broadcast

5. - E1E01

What is the minimum number of qualified VEs required to administer an Element 4 amateur operator license examination?

Select	Answer
A	4
B	2
C	5
D	3

6. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	The transmission must not be used to obscure the meaning of any communication
B	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
C	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
D	All of these choices are correct

7. - E2A12

What is one way to predict the location of a satellite at a given time?

Select	Answer
A	By calculations using the Keplerian elements for the specified satellite
B	By adding the mean anomaly to the orbital inclination
C	By means of the Doppler data for the specified satellite
D	By subtracting the mean anomaly from the orbital inclination

8. - E2B13

How many lines are commonly used in each frame of an amateur slow-scan color television picture?

Select	Answer
A	60 or 100
B	128 or 256
C	180 or 360
D	30 or 60

9. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To allocate frequencies for DXpeditions
B	To relay calls to and from a DX station
C	To handle the receiving and sending of confirmation cards for a DX station
D	To run a net to allow many stations to contact a rare DX station

10. - E2D03

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

Select	Answer
A	FSK441
B	JT65
C	Olivia
D	PACTOR III

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	300-baud packet
B	PSK31
C	MFSK16
D	170 Hz shift, 45 baud RTTY

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	500 miles, if the Moon is at perigee
C	2000 miles, if the Moon is at apogee
D	5000 miles, if the Moon is at perigee

13. - E3B13

Why is chordal hop propagation desirable?

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

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately four times the distance
B	By approximately twice the distance
C	By approximately 15 percent of the distance
D	By approximately 50 percent of the distance

15. - E4A08

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

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

16. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	The transmitter is not properly neutralized
B	There is more power going into the antenna
C	There is possibly a short to ground in the feed line
D	There is an impedance mismatch between the antenna and feed line

17. - E4C02

Which of the following portions of a receiver can be effective in eliminating image signal interference?

Select	Answer
A	A front-end filter or pre-selector
B	A narrow IF filter
C	A properly adjusted product detector
D	A notch filter

18. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Nonlinear circuits or devices
B	Positive feedback
C	Too little gain
D	Lack of neutralization

19. - E4E15

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Common mode currents on the shield and conductors
B	Low inductance ground connections at both ends of the shield
C	Tying all ground connections to a common point resulting in differential mode currents in the shield
D	Use of braided shielding material

20. - E5A15

Which of the following can increase Q for inductors and capacitors?

Select	Answer
A	Lower reactance
B	Lower self-resonant frequency
C	Higher self-resonant frequency
D	Lower losses

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

Select	Answer
A	Voltage and current are in phase
B	Voltage leads current by 90 degrees
C	Voltage and current are 180 degrees out of phase
D	Current leads voltage by 90 degrees

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 6
B	Point 4
C	Point 5
D	Point 2

23. - E5D03

What is microstrip?

Select	Answer
A	Miniature coax used for low power applications
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	Lightweight transmission line made of common zip cord

24. - E6A05

What is the alpha of a bipolar junction transistor?

Select	Answer
A	The change of collector current with respect to emitter current
B	The change of collector current with respect to base current
C	The change of base current with respect to collector current
D	The change of collector current with respect to gate current

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As balanced mixers in FM generation
B	As a variable capacitance in an automatic frequency control circuit
C	As a VHF/UHF mixer or detector
D	As a constant voltage reference in a power supply

26. - E6C02

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

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

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From less than 20 Hz to approximately 300 MHz
B	From approximately 10 Hz to no more than 3000 kHz
C	From a few kHz to no more than 30 MHz
D	From about 100 kHz to at least 1000 GHz

28. - E6E09

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

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

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	A lens and a photomultiplier
D	An amplitude modulated helium-neon laser

30. - E7A08

What logical operation does an OR gate perform?

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

31. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune both the input and output for maximum power
B	Tune the stage for maximum SWR
C	Use a phase inverter in the output filter
D	Install parasitic suppressors and/or neutralize the stage

32. - E7C04

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

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

33. - E7D16

When several electrolytic filter capacitors are connected in series to increase the operating voltage of a power supply filter circuit, why should resistors be connected across each capacitor?

Select	Answer
A	To equalize, as much as possible, the voltage drop across each capacitor
B	To provide a minimum load current to reduce voltage excursions at light loads
C	All of these choices are correct
D	To provide a safety bleeder to discharge the capacitors when the supply is off

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	The two input frequencies along with their sum and difference frequencies
B	Two and four times the original frequency
C	The sum, difference and square root of the input frequencies
D	1.414 and 0.707 times the input frequency

35. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
B	Incoming RF is converted to a control voltage for a voltage controlled oscillator
C	Software is converted from source code to object code during operation of the receiver
D	A switching mixer is used to generate I and Q signals directly from the RF input

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	1
B	0.03
C	38
D	76

37. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Nyquist limit noise
B	Digital conversion noise
C	Broadband noise
D	Spurious signals at discrete frequencies

38. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all of its harmonics?

Select	Answer
A	A square wave
B	A cosine wave
C	A sawtooth wave
D	A sine wave

39. - E8B07

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

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

40. - E8C06

What is the necessary bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	0.3 kHz
B	0.5 kHz
C	0.1 Hz
D	1.0 kHz

41. - E8D09

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

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

42. - E9A04

Which of the following factors may affect the feed point impedance of an antenna?

Select	Answer
A	Antenna height, conductor length/diameter ratio and location of nearby conductive objects
B	The settings of an antenna tuner at the transmitter
C	Sunspot activity and time of day
D	Transmission-line length

43. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the 3 dB beam-width?

Select	Answer
A	75 degrees
B	50 degrees
C	30 degrees
D	25 degrees

44. - E9C13

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

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

45. - E9D06

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Select	Answer
A	It becomes flat
B	It is increased
C	It is decreased
D	No change occurs

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

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

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	Reactance axis
B	Polar axis
C	Impedance axis
D	Prime axis

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It has a bidirectional pattern
B	It is non-rotatable
C	It is practical for use only on VHF bands
D	It receives equally well in all directions

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polytetrafluroethylene
B	Polymorphic silicon
C	Polychlorinated Biphenyls
D	Polyethylene

Figure E5-2

Figure E7-4

Figure E9-1

Figure E9-3