US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

Select	Answer
A	300 kHz to 3 MHz
B	3 to 30 MHz
C	30 to 300 MHz
D	300 to 3000 MHz

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to a dipole
B	50 watts PEP effective radiated power relative to an isotropic radiator
C	100 watts PEP effective radiated power relative to an isotropic radiator
D	100 watts PEP effective radiated power relative to the gain of a half-wave dipole

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

Select	Answer
A	All these choices are correct
B	Reduce the repeater antenna HAAT (Height Above Average Terrain)
C	File an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
D	Cease operation or make changes to the repeater to mitigate the interference

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Communications incidental to the purpose of the amateur service and remarks of a personal nature
B	Business-related messages for non-profit organizations
C	Messages intended for users of the maritime satellite service
D	All these choices are correct

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

Select	Answer
A	A label with the name, address, and telephone number of the station licensee
B	All these choices are correct
C	A photocopy of the station license
D	A label with the name, address, and telephone number of the control operator

6. - E1E01

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

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

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 420 MHz
B	Only on amateur frequencies above 50 MHz
C	Only on amateur frequencies above 144 MHz
D	Only on amateur frequencies above 222 MHz

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

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

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	A special IF converter
B	A special notch filter to remove synchronization pulses
C	A special front end limiter
D	No other hardware is needed

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send only the last two letters of your call sign until you make contact
B	Send your full call sign once or twice
C	Send the call sign of the DX station three times, the words this is,then your call sign three times
D	Send your full call sign and grid square

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	Uses only a 65 Hz bandwidth
B	The ability to decode signals which have a very low signal-to-noise ratio
C	Permits fast-scan TV transmissions over narrow bandwidth
D	Easily copied by ear if necessary

12. - E2E03

How is the timing of FT4 contacts organized?

Select	Answer
A	Stations take turns on alternate days
B	By exchanging ACK/NAK packets
C	Alternating transmissions at 7.5 second intervals
D	It depends on the lunar phase

13. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the moon is full
B	When the moon is at apogee
C	When the MUF is above 30 MHz
D	When the moon is at perigee

14. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between points at the same latitude
B	Propagation between a point on the equator and its antipodal point
C	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
D	Propagation between points located on the magnetic equator

15. - E3C14

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

Select	Answer
A	Downward bending due to density variations in the atmosphere
B	E-region skip
C	Due to the Doppler effect
D	D-region skip

16. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	All these choices are correct
B	Antenna analyzers do not need an external RF source
C	Antenna analyzers display a time-varying representation of the modulation envelope
D	Antenna analyzers automatically tune your antenna for resonance

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S12
B	S11
C	S22
D	S21

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

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

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

Select	Answer
A	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
B	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals
C	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
D	Oscillator instability and severe audio distortion of all but the strongest received signals

20. - E4E07

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	Tying all ground connections to a common point resulting in differential-mode currents in the shield
C	Low inductance ground connections at both ends of the shield
D	Use of braided shielding material

21. - E5A09

How is the Q of an RLC parallel resonant circuit calculated?

Select	Answer
A	Resistance divided by the reactance of either the inductance or capacitance
B	Reactance of the inductance multiplied by the reactance of the capacitance
C	Reactance of either the inductance or capacitance multiplied by the resistance
D	Reactance of either the inductance or capacitance divided by the resistance

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

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

23. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms inductive reactance
B	50 ohms resistance in series with 25 ohms inductive reactance
C	25 ohms resistance in series with 50 ohms capacitive reactance
D	50 ohms resistance in series with 25 ohms capacitive reactance

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the apparent power by the power factor
B	By multiplying the apparent power by the power factor
C	By multiplying the reactive power by the power factor
D	By dividing the reactive power by the power factor

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter resistance of approximately 6 to 7 ohms
B	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
C	Base-to-emitter voltage of approximately 6 to 7 volts
D	Base-to-emitter voltage of approximately 0.6 to 0.7 volts

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a variable capacitance in an automatic frequency control circuit
B	As a VHF/UHF mixer or detector
C	As a constant voltage reference in a power supply
D	As a rectifier in high current power supplies

27. - E6C03

What is tri-state logic?

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

28. - E6D12

What is inductor saturation?

Select	Answer
A	Adjacent inductors become over-coupled
B	The inductor windings are over-coupled
C	The ability of the inductor's core to store magnetic energy has been exceeded
D	The inductor's voltage rating is exceeded causing a flashover

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	DIP
B	SOT
C	PLCC
D	Ball grid array

30. - E6F05

Which describes an optical shaft encoder?

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

31. - 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 0 at its output if all inputs are logic 1
D	It produces logic 1 at its output if all inputs are logic 0

32. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Fixed bias
B	Emitter bypass
C	Self bias
D	Output load resistor

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

Select	Answer
A	A matching network in which all components are isolated from ground
B	A Pi-network with an additional series inductor on the output
C	A network with only three discrete parts
D	A Phase Inverter Load network

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	It is a brute force filter for the output
B	It bypasses rectifier output ripple around D1
C	To self-resonate at the hum frequency
D	To provide fixed DC bias for Q1

35. - 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	1.414 and 0.707 times the input frequency
C	The square root of the product of input frequencies
D	Two and four times the original frequency

36. - 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	Software is converted from source code to object code during operation of the receiver
C	A switching mixer is used to generate I and Q signals directly from the RF input
D	Incoming RF is converted to a control voltage for a voltage controlled oscillator

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It does not vary with frequency
B	It decreases linearly with increasing frequency
C	It increases linearly with increasing frequency
D	It decreases logarithmically with increasing frequency

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through link coupling
B	Through a neutralizing capacitor
C	Through a quartz crystal
D	Through a tapped coil

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Harmonic regeneration
B	Successive approximation
C	Level shifting
D	Phase reversal

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	2.14
B	0.47
C	47
D	0.214

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

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

42. - E8D05

What is the most common method of reducing key clicks?

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

43. - E9A06

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	317 watts
B	2000 watts
C	126 watts
D	300 watts

44. - E9B03

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

Select	Answer
A	14 dB
B	18 dB
C	12 dB
D	24 dB

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A dipole constructed from zip cord
B	An end-fed dipole antenna
C	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
D	An omni-directional antenna commonly used for satellite communications

46. - 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 lower the radiation angle
C	To minimize the Q
D	To swamp out harmonics

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
B	It is used to feed low-impedance loads from a high-impedance source
C	It is used to feed high-impedance antennas from a low-impedance source
D	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	A capacitive reactance
B	The same as the characteristic impedance of the line
C	Zero
D	An inductive reactance

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant reactance
B	Frequency
C	Points with constant resistance
D	SWR

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A four-element, high-gain vertical array invented by George Pennant
B	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
C	A stealth antenna built to look like a flagpole
D	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms

Figure E7-1

Figure E7-2

Figure E9-1