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

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Florida surrounding Cape Canaveral
B	An area in Puerto Rico surrounding the Arecibo Radio Telescope
C	An area in New Mexico surrounding the White Sands Test Area
D	An area surrounding the National Radio Astronomy Observatory

3. - E1C01

What is a remotely controlled station?

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

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	2 meters
B	6 meters, 2 meters, and 1.25 meters
C	2 meters and 1.25 meters
D	6 meters and 2 meters

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 80%
B	Minimum passing score of 70%
C	Minimum passing score of 77%
D	Minimum passing score of 74%

6. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must be capable of external RF switching between its input and output networks
B	It must exhibit a gain of 0 dB or less over its full output range
C	It must produce full legal output when driven by not more than 5 watts of mean RF input power
D	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	The 2 meter and 70 centimeter bands
B	Which sideband to use
C	The 23 centimeter and 13 centimeter bands
D	FM and Digital Store-and-Forward systems

8. - E2B19

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

Select	Answer
A	They are not permitted above 54 MHz
B	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
C	None; they are allowed on all amateur frequencies
D	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

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	The ARRL section of the remote station
B	/R# where # is the district of the remote station
C	No additional indicator is required
D	/ followed by the USPS two letter abbreviation for the state in which the remote station is located

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	JT65
B	FSK441
C	PACTOR III
D	Olivia

11. - E2E08

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

Select	Answer
A	PACTOR
B	AMTOR
C	RTTY
D	Hellschreiber

12. - E3A03

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

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

13. - E3B09

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

Select	Answer
A	Around the solstices, especially the summer solstice
B	Around the equinoxes, especially the fall equinox
C	Around the equinoxes, especially the spring equinox
D	Around the solstices, especially the winter solstice

14. - E3C14

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

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

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and frequency
B	SWR and frequency
C	RF amplitude and time
D	SWR and time

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. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The minimum discernible signal
B	The multiplex distortion stability
C	The meter display sensitivity
D	The maximum detectable spectrum

18. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Lack of neutralization
B	Nonlinear circuits or devices
C	Too little gain
D	Positive feedback

19. - E4E02

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

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

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

Select	Answer
A	Low, as compared to the circuit resistance
B	Approximately equal to capacitive reactance
C	Approximately equal to circuit resistance
D	Approximately equal to inductive reactance

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	B
B	X
C	G
D	Y

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

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

23. - E5D13

How much power is consumed in a circuit consisting of a 100 ohm resistor in series with a 100 ohm inductive reactance drawing 1 ampere?

Select	Answer
A	100 Watts
B	141.4 Watts
C	70.7 Watts
D	200 Watts

24. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Beta cutoff frequency
B	Corner frequency
C	Alpha cutoff frequency
D	Alpha rejection frequency

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Zener diode
B	Tunnel diode
C	Varactor diode
D	Silicon-controlled rectifier

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	3
B	2
C	4
D	1

27. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
B	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
C	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
D	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel

28. - E6E08

How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

Select	Answer
A	MMICs require no operating bias
B	Through a resistor and/or RF choke connected to the amplifier output lead
C	Directly to the bias voltage (VCC IN) lead
D	Through a capacitor and RF choke connected to the amplifier input lead

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	They are hard to view in high ambient light conditions
B	They only display alphanumeric symbols
C	They may be hard view through polarized lenses
D	All of these choices are correct

30. - E7A10

What is a truth table?

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

31. - E7B06

Which of the following amplifier types reduces or eliminates even order harmonics?

Select	Answer
A	Class AB
B	Push-push
C	Class C
D	Push-pull

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	An all-pass filter
B	A band-pass filter
C	A Pi-network filter
D	A notch filter

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

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

34. - E7E10

How does a diode detector function?

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

35. - E7F08

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

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

36. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	7
B	28
C	14
D	0.07

37. - E7H06

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

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

38. - E8A13

Which of these methods is commonly used to convert analog signals to digital signals?

Select	Answer
A	Sequential sampling
B	Level shifting
C	Phase reversal
D	Harmonic regeneration

39. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)?

Select	Answer
A	It does not depend on the RF carrier frequency
B	It decreases as the RF carrier frequency increases
C	It varies with the square root of the RF carrier frequency
D	It increases as the RF carrier frequency increases

40. - E8C04

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

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

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Phase compandored spread spectrum
B	Direct sequence
C	Frequency hopping
D	Binary phase-shift keying

42. - E9A16

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	300 watts
B	126 watts
C	317 watts
D	2000 watts

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference
B	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna
C	Draw two imaginary lines through the ends of the elements and measure the angle between the lines
D	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna

44. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

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

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Lower Q
B	Greater structural strength
C	Higher losses
D	Improved radiation efficiency

46. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The gamma match
B	The stub match
C	The epsilon match
D	The delta match

47. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically one-half wavelength long at 14.10 MHz?

Select	Answer
A	71 meters
B	15 meters
C	20 meters
D	10 meters

48. - E9G07

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

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

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	A very sharp peak
B	Broad band response
C	A very sharp single null
D	High-radiation angle

50. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Blood clotting from the intense magnetic field
B	Hearing loss caused by high voltage corona discharge
C	Ingestion of ozone gas from the cooling system
D	Localized heating of the body from RF exposure in excess of the MPE limits

Figure E6-5

Figure E7-3

Figure E7-4

Figure E9-3