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

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station except a Technician class
B	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
C	Only those club stations licensed to Amateur Extra class operators
D	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)

3. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under automatic control the control operator is not required to be present at the control point
B	Under local control a control operator is not required to be present at a control point
C	Under automatic control there is no control operator
D	Under local control there is no control operator

4. - E1D02

What is the amateur satellite service?

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

5. - E1E02

Where are the questions for all written U.S. amateur license examinations listed?

Select	Answer
A	In FCC Part 97
B	In the appropriate FCC Report and Order
C	In a question pool maintained by all the VECs
D	In a question pool maintained by the FCC

6. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide for experimental amateur communications
B	To allow regular operation on Land Mobile channels
C	To provide temporary operation while awaiting normal licensing
D	To provide additional spectrum for personal use

7. - E2A10

Why may the received signal from an amateur satellite exhibit a rapidly repeating fading effect?

Select	Answer
A	Because of the satellite's low orbital altitude
B	Because of the Doppler Effect
C	Because of ionospheric absorption
D	Because the satellite is spinning

8. - E2B19

What special operating frequency restrictions are imposed on slow scan TV transmissions?

Select	Answer
A	None; they are allowed on all amateur frequencies
B	They are restricted to phone band segments and their bandwidth can be no greater than that of a voice signal of the same modulation type
C	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
D	They are not permitted above 54 MHz

9. - E2C09

What type of equipment is commonly used to implement a ham radio mesh network?

Select	Answer
A	A 2 meter VHF transceiver with a 1200 baud modem
B	A 440 MHz transceiver with a 9600 baud modem
C	An optical cable connection between the USB ports of 2 separate computers
D	A standard wireless router running custom software

10. - E2D04

What is the purpose of digital store-and-forward functions on an Amateur Radio satellite?

Select	Answer
A	To delay download of telemetry between satellites
B	To store digital messages in the satellite for later download by other stations
C	To relay messages between satellites
D	To upload operational software for the transponder

11. - E2E11

What is the difference between direct FSK and audio FSK?

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

12. - E3A15

What is an electromagnetic wave?

Select	Answer
A	A wave consisting of two electric fields at parallel right angles to each other
B	A wave consisting of two magnetic fields at right angles to each other
C	A wave consisting of an electric field and a magnetic field oscillating at right angles to each other
D	A wave of alternating current, in the core of an electromagnet

13. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	160 meters to 10 meters
B	6 meters to 2 meters
C	160 meters to 40 meters
D	30 meters to 10 meters

14. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	D-region skip
B	Downward bending due to density variations in the atmosphere
C	Downward bending due to aurora refraction
D	E-region skip

15. - E4A09

When using a computer's soundcard input to digitize signals, what is the highest frequency signal that can be digitized without aliasing?

Select	Answer
A	The same as the sample rate
B	One-half the sample rate
C	One-tenth the sample rate
D	It depends on how the data is stored internally

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S12
B	S22
C	S11
D	S21

17. - E4C08

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

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

18. - E4D06

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

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

19. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	Nearby signals may appear to be excessively wide even if they meet emission standards
B	Received audio in the speech range might have an echo effect
C	The audio frequency bandwidth of the received signal might be compressed
D	FM signals can no longer be demodulated

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching bandwidth is decreased
B	It has no effect on impedance matching
C	Matching bandwidth is increased
D	Matching range is increased

21. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage lagging the current
B	68.2 degrees with the voltage leading the current
C	14.0 degrees with the voltage leading the current
D	68.2 degrees with the voltage lagging the current

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. - E5D04

Why are short connections necessary at microwave frequencies?

Select	Answer
A	To reduce noise figure
B	To increase neutralizing resistance
C	To reduce phase shift along the connection
D	Because of ground reflections

24. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

Select	Answer
A	Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
B	Only N-type semiconductor material can conduct current
C	Only P-type semiconductor material can conduct current
D	Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region

25. - E6B10

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	6
B	1
C	5
D	7

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	High speed operation
B	Ability to connect many device outputs to a common bus
C	More efficient arithmetic operations
D	Low power consumption

27. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores exhibit greater hysteresis
B	Toroidal cores have lower Q characteristics
C	Toroidal cores confine most of the magnetic field within the core material
D	Toroidal cores make it easier to couple the magnetic energy into other components

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Wave-soldering construction
B	Point-to-point construction
C	Microstrip construction
D	Ground-plane construction

29. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of light to electrical energy
B	The tendency of a battery to discharge when used outside
C	The conversion of voltage to current when exposed to light
D	The conversion of electrical energy to mechanical energy

30. - E7A01

Which is a bi-stable circuit?

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

31. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they invert the sidebands causing distortion
B	Because they maintain the sidebands, thus causing multiple duplicate signals
C	Because they are relatively close in frequency to the desired signal
D	Because they are relatively far in frequency from the desired signal

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

33. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-3?

Select	Answer
A	It provides negative feedback to improve regulation
B	It provides a constant load for the voltage source
C	It increases the current-handling capability of the regulator
D	It provides D1 with current

34. - E7E10

How does a diode detector function?

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

35. - E7F11

What sets the minimum detectable signal level for an SDR in the absence of atmospheric or thermal noise?

Select	Answer
A	Data storage transfer rate
B	Missing codes and jitter
C	Sample clock phase noise
D	Reference voltage level and sample width in bits

36. - E7G12

What is an integrated circuit operational amplifier?

Select	Answer
A	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
B	A RF amplifier used in the UHF and microwave regions
C	A digital audio amplifier whose characteristics are determined by components external to the amplifier
D	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance

37. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a temperature-controlled high Q dielectric resonator
B	Use a rubidium stabilized reference oscillator
C	Use a GPS signal reference
D	All of these choices are correct

38. - E8A12

What is an advantage of using digital signals instead of analog signals to convey the same information?

Select	Answer
A	Digital signals always occupy a narrower bandwidth
B	Less complex circuitry is required for digital signal generation and detection
C	Digital signals can be regenerated multiple times without error
D	All of these choices are correct

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. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	15.36 kHz
B	4.8 kHz
C	9.6 kHz
D	5.76 kHz

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Low-pass filters at the transmitter output
B	High-pass filters at the transmitter output
C	Reduce keying waveform rise and fall times
D	Increase keying waveform rise and fall times

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Isolate the coax shield from ground
B	Shorten the radiating element
C	Reduce the diameter of the radiating element
D	Install a good radial system

43. - E9B13

What does the abbreviation NEC stand for when applied to antenna modeling programs?

Select	Answer
A	Numerical Electromagnetic Code
B	Next Element Comparison
C	Numeric Electrical Computation
D	National Electrical Code

44. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

Select	Answer
A	A figure-8 end-fire along the axis of the array
B	Cardioid
C	A figure-8 broadside to the axis of the array
D	Omni-directional

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The SWR is reduced
B	The front-to-back ratio decreases
C	The frequency response is widened over the whole frequency band
D	The front-to-back ratio increases

46. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To provide DC isolation between the feed line and the antenna
B	To provide a rejection notch that prevents the radiation of harmonics
C	To transform the antenna impedance to a higher value
D	To cancel the inductive reactance of the matching network

47. - E9F07

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

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

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. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It increases the sensitivity of a DF antenna array
B	It provides diversity reception that cancels multipath signals
C	It allows DF antennas to receive signals at different vertical angles
D	It modifies the pattern of a DF antenna array to provide a null in one direction

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Uranium Hexafluoride
B	Beryllium Oxide
C	Mica
D	Zinc oxide

Figure E5-2

Figure E6-3

Figure E7-3