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

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1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	Yes, because the displayed frequency is within the 75 meter phone band segment
B	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
C	No, the sideband will extend beyond the edge of the phone band segment
D	Yes, because the DX station initiated the contact

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

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

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
B	All of these choices are correct
C	The space station must cease all transmissions after 5 years
D	The space station must be capable of changing its orbit whenever such a change is ordered by NASA

5. - E1E13

Which of these choices is an acceptable method for monitoring the applicants if a VEC opts to conduct an exam session remotely?

Select	Answer
A	Record the exam session on video tape for later review by the VE team
B	Have each applicant sign an affidavit stating that all session rules were followed
C	Use a real-time video link and the Internet to connect the exam session to the observing VEs
D	The exam proctor observes the applicants and reports any violations

6. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
B	It was imported from a manufacturer in another country and was certificated by that country's government
C	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
D	The equipment dealer assembled it from a kit

7. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	FM and CW
B	SSB and SSTV
C	All of these choices are correct
D	PSK and Packet

8. - E2B10

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	15 KHz
B	3 KHz
C	20 KHz
D	10 KHz

9. - E2C05

What is the function of a DX QSL Manager?

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

10. - E2D01

Which of the following digital modes is especially designed for use for meteor scatter signals?

Select	Answer
A	FSK441
B	WSPR
C	Hellschreiber
D	APRS

11. - E2E13

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	Another station you are unable to hear is using the frequency
B	The protocol version you are using is not the supported by the digital station
C	Your transmit frequency is incorrect
D	All of these choices are correct

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	RTTY
B	SSB
C	FM
D	CW

13. - E3B11

At what time of day is Sporadic-E propagation most likely to occur?

Select	Answer
A	Any time
B	Early evening
C	Around sunset
D	Around sunrise

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	Increased transequatorial propagation likely
B	A solar flare has occurred
C	Long-path propagation is occurring
D	A meteor ping

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	An antenna analyzer
D	A Q meter

16. - E4B04

If a frequency counter with a specified accuracy of +/- 0.1 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	1.4652 Hz
B	0.1 MHz
C	14.652 Hz
D	1.4652 kHz

17. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	It improves sensitivity by reducing front end noise
B	All of these choices are correct
C	It improves dynamic range by attenuating strong signals near the receive frequency
D	It improves intelligibility by using low Q circuitry to reduce ringing

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

Select	Answer
A	Adjacent channel interference
B	Intermodulation interference
C	Amplifier desensitization
D	Neutralization

19. - E4E12

What is one disadvantage of using some types of automatic DSP notch-filters when attempting to copy CW signals?

Select	Answer
A	A DSP filter can remove the desired signal at the same time as it removes interfering signals
B	Any nearby signal passing through the DSP system will overwhelm the desired signal
C	Ringing in the DSP filter will completely remove the spaces between the CW characters
D	Received CW signals will appear to be modulated at the DSP clock frequency

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Phase shift can become uncontrolled
B	Internal voltages and circulating currents increase
C	Parasitic effects are minimized
D	Fewer components are needed for the same performance

21. - E5B03

What happens to the phase angle of a reactance when it is converted to a susceptance?

Select	Answer
A	It is unchanged
B	The susceptance phase angle is the inverse of the reactance phase angle
C	It is shifted by 90 degrees
D	The sign is reversed

22. - E5C17

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor, a 0.64-microhenry inductor and an 85-picofarad capacitor at 24.900 MHz?

Select	Answer
A	Point 3
B	Point 5
C	Point 8
D	Point 1

23. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in circuit Q
B	Power lost because of capacitor leakage
C	Wattless, nonproductive power
D	Power consumed in wire resistance in an inductor

24. - E6A15

Which semiconductor material contains excess holes in the outer shell of electrons?

Select	Answer
A	N-type
B	Bipolar-type
C	P-type
D	Superconductor-type

25. - E6B01

What is the most useful characteristic of a Zener diode?

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

26. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Lower power consumption
B	Immune to damage from static discharge
C	Lower distortion
D	Differential output capability

27. - E6D15

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

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

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	-10 dB
B	-20 dBm
C	2 dB
D	44 dBm

29. - E6F12

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

Select	Answer
A	Protons
B	Holes
C	Electrons
D	Photons

30. - E7A10

What is a truth table?

Select	Answer
A	A list of inputs and corresponding outputs for a digital device
B	A table of logic symbols that indicate the logic states of an op-amp
C	A diagram showing logic states when the digital device output is true
D	A table of logic symbols that indicate the high logic states of an op-amp

31. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common emitter
B	Emitter follower
C	Common base
D	Common collector

32. - E7C08

Which of the following factors has the greatest effect in helping determine the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The DC voltage applied to the quartz crystal
B	The relative frequencies of the individual crystals
C	The gain of the RF stage preceding the filter
D	The amplitude of the signals passing through the filter

33. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Matching of day and night charge rates
B	Prevention of battery damage due to overcharge
C	Control of electrolyte levels during battery discharge
D	Prevention of battery undercharge

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An automatic band-switching circuit
B	A circuit for filtering two closely adjacent signals
C	A circuit for detecting FM signals
D	An FM generator circuit

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

36. - E7G03

What is the typical input impedance of an integrated circuit op-amp?

Select	Answer
A	Very high
B	1000 ohms
C	Very low
D	100 ohms

37. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A hybrid synthesizer
B	A phase locked loop synthesizer
C	A diode-switching matrix synthesizer
D	A direct digital synthesizer

38. - E8A09

How many levels can an analog-to-digital converter with 8 bit resolution encode?

Select	Answer
A	256 divided by the gain of the input amplifier
B	256
C	8
D	8 multiplied by the gain of the input amplifier

39. - E8B07

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

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

40. - E8C04

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

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

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Signal to noise ratio
B	Baud rate
C	Repeat Request Rate (RRR)
D	Intermodulation Distortion (IMD)

42. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	8.15 dB
B	2.79 dB
C	6.0 dB
D	3.85 dB

43. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	14 dB
B	12 dB
C	18 dB
D	24 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 lobes align more in the direction of the wire
B	The front-to-back ratio decreases
C	The lobes become more perpendicular to the wire
D	The vertical angle increases

45. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize losses
B	To minimize the Q
C	To swamp out harmonics
D	To maximize losses

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element reactance must be inductive
B	The driven element resonance must be lower than the operating frequency
C	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
D	The driven element reactance must be capacitive

47. - E9F03

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

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

48. - E9G08

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

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

49. - E9H07

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

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

50. - E0A10

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

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

Figure E5-2

Figure E7-1

Figure E9-1