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

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 43 dB below
B	At least 63 dB below
C	At least 53 dB below
D	At least 73 dB below

3. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	Never
B	When approved by the National Telecommunication and Information Administration
C	When agreed upon by the sending or receiving station
D	Only when transmitting RTTY or data emissions

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	Two-way radiotelephone transmissions in excess of 1000 feet
B	One-way transmission of measurements at a distance from the measuring instrument
C	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
D	Two-way single channel transmissions of data

5. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
B	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
C	The prospective VE obtains accreditation from the FCC
D	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau

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

7. - E2A08

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

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

8. - E2B08

Which of the following is a common method of transmitting accompanying audio with amateur fast-scan television?

Select	Answer
A	All of these choices are correct
B	Frequency-modulated sub-carrier
C	A separate VHF or UHF audio link
D	Frequency modulation of the video 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	Switch to a lower frequency HF band
B	Wait 24 hours before attempting another communication on the band
C	Wait 90 minutes or so for the signal degradation to pass
D	Switch to a higher frequency HF band

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Latitude and longitude
B	Polar coordinates
C	Radio direction finding spectrum analysis
D	Time and frequency

11. - E2E08

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

Select	Answer
A	PACTOR
B	AMTOR
C	Hellschreiber
D	RTTY

12. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Wind shear
B	Dust devil
C	The jet stream
D	Temperature inversion

13. - E3B06

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

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

14. - E3C08

What does the space weather term G5 mean?

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

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

Select	Answer
A	A wattmeter
B	A spectrum analyzer
C	A logic analyzer
D	A time-domain reflectometer

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S12
B	S21
C	S22
D	S11

17. - E4C12

What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

Select	Answer
A	Filter ringing
B	Thermal-noise distortion
C	Output-offset overshoot
D	Undesired signals may be heard

18. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the third order intercept point
B	The difference in dB between the noise floor and the level of an incoming signal which will cause 1 dB of gain compression
C	The minimum difference in dB between the levels of two FM signals which will cause one signal to block the other
D	The minimum difference in dB between two signals which produce third order intermodulation products greater than the noise floor

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which have a sharply peaked frequency distribution
B	Signals which appear at one IF but not another
C	Signals which appear across a wide bandwidth
D	Signals which are constant at all IF levels

20. - E5A12

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	31.4 kHz
B	15.7 kHz
C	218.3 kHz
D	436.6 kHz

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	440 seconds
D	55 seconds

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 7
B	Point 3
C	Point 1
D	Point 8

23. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is dissipated as heat in the circuit
B	It is dissipated as kinetic energy in the circuit
C	It is dissipated in the formation of inductive and capacitive fields
D	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated

24. - E6A05

What is the alpha of a bipolar junction transistor?

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

25. - E6B09

What is a common use for point contact diodes?

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

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	It is totally immune to electrostatic damage
B	Its simplicity results in much less expensive devices than standard CMOS
C	All of these choices are correct
D	It has the high input impedance of CMOS and the low output impedance of bipolar transistors

27. - E6D08

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

Select	Answer
A	Powdered-iron cores generally have greater initial permeability
B	Powdered-iron cores generally require fewer turns to produce a given inductance
C	Powdered-iron cores use smaller diameter wire for the same inductance
D	Powdered-iron cores generally maintain their characteristics at higher currents

28. - E6E09

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

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

29. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device for generating RTTY signals by means of a rotating light source
B	A digital encryption device often used to encrypt spacecraft control signals
C	A device which measures the strength of a beam of light using analog to digital conversion
D	A device which detects rotation of a control by interrupting a light source with a patterned wheel

30. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	8
B	1
C	2
D	4

31. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	High power gain
B	Low bandwidth
C	High filament voltage
D	Low input impedance

32. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	A Butterworth filter
B	An active LC filter
C	A passive op-amp filter
D	A Chebyshev filter

33. - E7D14

What is one purpose of a "bleeder" resistor in a conventional unregulated power supply?

Select	Answer
A	To improve output voltage regulation
B	To cut down on waste heat generated by the power supply
C	To balance the low-voltage filament windings
D	To boost the amount of output current

34. - E7E10

How does a diode detector function?

Select	Answer
A	By rectification and filtering of RF signals
B	By breakdown of the Zener voltage
C	By mixing signals with noise in the transition region of the diode
D	By sensing the change of reactance in the diode with respect to frequency

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Removing unnecessary significant digits
B	Reducing the effective sample rate by removing samples
C	Attenuating the signal
D	Converting data to binary code decimal form

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As an audio filter in a receiver
B	As a high-pass filter used to block RFI at the input to receivers
C	As a low-pass filter used between a transmitter and a transmission line
D	For smoothing power supply output

37. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	Wirewound resistors
B	Non-inductive resistors
C	NP0 capacitors
D	Toroidal inductors

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	All of these choices are correct
B	Immunity to out of sequence coding reduces spurious responses
C	Very low power consumption decreases frequency drift
D	Very high speed allows digitizing high frequencies

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	1000
B	3
C	0.3
D	3000

40. - E8C01

How is Forward Error Correction implemented?

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

41. - E8D09

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

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

42. - E9A14

What is meant by the radiation resistance of an antenna?

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

43. - E9B15

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

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

44. - E9C13

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

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

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 collinear to each other with the driven elements fed 180 degrees out of phase
C	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 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. - E9E11

What is an effective way of matching a feed line to a VHF or UHF antenna when the impedances of both the antenna and feed line are unknown?

Select	Answer
A	Use a 50 ohm 1:1 balun between the antenna and feed line
B	Connect a parallel-resonant LC network across the antenna feed terminals
C	Use the universal stub matching technique
D	Connect a series-resonant LC network across the antenna feed terminals

47. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Higher SWR
B	Lower velocity factor
C	Lower loss
D	Smaller reflection coefficient

48. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical wavelength
B	In fractions of antenna electrical frequency
C	In fractions of transmission line electrical frequency
D	In fractions of antenna electrical wavelength

49. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It narrows the bandwidth of the received signal to improve signal to noise ratio
B	It compensates for the effects of an isotropic antenna, thereby improving directivity
C	It prevents receiver overload which could make it difficult to determine peaks or nulls
D	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	Use an antenna modeling program to calculate field strength at accessible locations
B	All of the choices are correct
C	Use a hand calculator plus Smith-chart equations to calculate the fields
D	Use a calibrated antenna analyzer

Figure E5-2

Figure E9-2