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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	Yes, the DX station initiated the contact
B	No, one of the sidebands of the CW signal will be out of the band
C	Yes, the displayed frequency is within the 80 meter CW band segment
D	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	All amateur service frequencies authorized to the control operator
B	Specific local government channels
C	Specific segments in the amateur service MF, HF, VHF and UHF bands
D	Military Auxiliary Radio System (MARS) channels

3. - E1C01

What is a remotely controlled station?

Select	Answer
A	A station operated away from its regular home location
B	A station controlled by someone other than the licensee
C	A station operating under automatic control
D	A station controlled indirectly through a control link

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station located more than 50 km above the Earth's surface
B	An amateur station that transmits telemetry consisting of measurements of upper atmosphere
C	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
D	An amateur station that transmits communications to initiate, modify or terminate functions of a space station

5. - E1E14

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Providing amateur operator license examination preparation training materials
B	Teaching an amateur operator license examination preparation course
C	No expenses are authorized for reimbursement
D	Preparing, processing, administering and coordinating an examination for an amateur radio license

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 General, Advanced or Amateur Extra Class operators
D	Only Technician, General, Advanced or Amateur Extra Class operators

7. - E2A13

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	LEO
B	Geomagnetic
C	Geostationary
D	HEO

8. - E2B15

What signals SSTV receiving equipment to begin a new picture line?

Select	Answer
A	Specific tone amplitudes
B	Specific tone frequencies
C	Elapsed time
D	A two-tone signal

9. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	6 m
B	33 cm
C	30 m
D	2 m

10. - E2D01

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

Select	Answer
A	APRS
B	WSPR
C	FSK441
D	Hellschreiber

11. - E2E03

How is the timing of JT65 contacts organized?

Select	Answer
A	Stations take turns on alternate days
B	Alternating transmissions at 1 minute intervals
C	It depends on the lunar phase
D	By exchanging ACK/NAK packets

12. - E3A10

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

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

13. - E3B13

Why is chordal hop propagation desirable?

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

14. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Vertical
B	Circular
C	Horizontal
D	Elliptical

15. - E4A15

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

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

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S11
B	S12
C	S21
D	S22

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The reference voltage of the analog-to-digital converter
B	One-half the maximum sampling buffer size
C	The maximum count value of the analog-to-digital converter
D	One-half the maximum sample rate

18. - E4D01

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

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

19. - E4E02

Which of the following types of receiver noise can often be reduced with a DSP noise filter?

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

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

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

21. - E5B02

What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial voltage?

Select	Answer
A	One discharge period
B	A discharge factor of one
C	An exponential discharge rate of one
D	One time constant

22. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A positive phase angle
B	A positive real part
C	A negative real part
D	A negative phase angle

23. - E5D05

Which parasitic characteristic increases with conductor length?

Select	Answer
A	Malleability
B	Permeability
C	Permittivity
D	Inductance

24. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The switching speed of the transistor
B	The breakdown voltage of the base to collector junction
C	The change in collector current with respect to base current
D	The frequency at which the current gain is reduced to 1

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Reverse voltage larger than the RF signal
B	A sub-harmonic pump signal
C	Capacitance of an RF coupling capacitor
D	Forward DC bias current

26. - E6C03

What is tri-state logic?

Select	Answer
A	Logic devices with 0, 1, and high impedance output states
B	Logic devices that utilize ternary math
C	Low power logic devices designed to operate at 3 volts
D	Proprietary logic devices manufactured by Tri-State Devices

27. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Non-linear core hysteresis
B	Inductive kickback
C	The skin effect
D	Inter-turn capacitance

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon dioxide
B	Silicon nitride
C	Silicon
D	Gallium nitride

29. - E6F01

What is photoconductivity?

Select	Answer
A	The decreased conductivity of an illuminated semiconductor
B	The conversion of photon energy to electromotive energy
C	The increased conductivity of an illuminated semiconductor
D	The conversion of electromotive energy to photon energy

30. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	A flip-flop
B	A multiplexer
C	An OR gate
D	An XOR gate

31. - E7B02

What is a Class D amplifier?

Select	Answer
A	A type of amplifier that uses switching technology to achieve high efficiency
B	A frequency doubling amplifier
C	An amplifier that uses drift-mode FETs for high efficiency
D	A low power amplifier that uses a differential amplifier for improved linearity

32. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a high-pass filter
B	It is a band-pass filter
C	It is a low-pass filter
D	It is a notch filter

33. - E7D01

What is one characteristic of a linear electronic voltage regulator?

Select	Answer
A	The conduction of a control element is varied to maintain a constant output voltage
B	The control element duty cycle is proportional to the line or load conditions
C	It has a ramp voltage as its output
D	It eliminates the need for a pass transistor

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

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	24
B	0.21
C	47
D	94

37. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Colpitts and Hartley
B	Negative feedback and balanced feedback
C	Armstrong and deForest
D	Pierce and Zener

38. - E8A08

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

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

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	3
B	1000
C	0.3
D	3000

40. - E8C05

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

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

41. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It is possible to transmit both upper and lower case text
B	It contains fewer information bits per character than any other code
C	It includes built in error correction features
D	It uses one character as a shift code to send numeric and special characters

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	3.85 dB
C	2.79 dB
D	6.0 dB

43. - E9B15

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

Select	Answer
A	28 dB
B	24 dB
C	3 dB
D	15 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 vertical angle increases
D	The lobes align more in the direction of the wire

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 swamp out harmonics
C	To minimize the Q
D	To maximize losses

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Velocity factor
B	Characteristic impedance
C	Dielectric constant
D	Reflection coefficient

47. - E9F07

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

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

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The reactance axis
B	The current axis
C	The resistance axis
D	The voltage axis

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	All of these choices are correct
B	Low loss coax transmission line is essential for good performance
C	Atmospheric noise is so high that gain over a dipole is not important
D	They must be erected at least 1/2 wavelength above the ground to attain good directivity

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

Figure E7-4

Figure E9-2

Figure E9-3