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

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1. - E1A03

With your transceiver displaying the carrier frequency of phone signals, you hear a station calling CQ on 14.349 MHz USB. Is it legal to return the call using upper sideband on the same frequency?

Select	Answer
A	No, the sideband will extend beyond the band edge
B	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz
C	Yes, because the displayed frequency is within the 20 meter band
D	Yes, because you were not the station calling CQ

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	2.0
B	1.0
C	3.0
D	0.5

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	18.110 MHz - 18.168 MHz
B	10.100 MHz - 10.150 MHz
C	29.500 MHz - 29.700 MHz
D	24.940 MHz - 24.990 MHz

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station that is not able to communicate using amateur satellites
B	Any amateur station on the surface of the Earth
C	An amateur station that transmits telemetry consisting of measurement of upper atmosphere
D	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space

5. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Maintain the application form with the VEC's records
B	Return the application document to the examinee
C	Destroy the application form
D	Send the application form to the FCC and inform the FCC of the grade

6. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
B	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
C	All of these choices are correct
D	The transmission must not be used to obscure the meaning of any communication

7. - E2A04

What is meant by the term mode as applied to an amateur radio satellite?

Select	Answer
A	The type of signals that can be relayed through the satellite
B	The satellite's uplink and downlink frequency bands
C	Whether the satellite is in a polar or equatorial orbit
D	The satellite's orientation with respect to the Earth

8. - E2B15

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

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

9. - 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

10. - E2D13

What type of modulation is used for JT65 contacts?

Select	Answer
A	PSK
B	IEEE 802.11
C	Multi-tone AFSK
D	RTTY

11. - E2E12

Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

Select	Answer
A	Remote
B	Automatic
C	Local
D	ALE can use any type of control

12. - E3A05

Tropospheric propagation of microwave signals often occurs along what weather related structure?

Select	Answer
A	Warm and cold fronts
B	Gray-line
C	Sprites and jets
D	Lightning discharges

13. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	1000 miles
B	2500 miles
C	7500 miles
D	5000 miles

14. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the Sun will cause disturbed conditions?

Select	Answer
A	Eastward
B	Northward
C	Westward
D	Southward

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

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S21
B	S22
C	S12
D	S11

17. - E4C17

Which of the following has the largest effect on an SDR receiver's linearity?

Select	Answer
A	RAM speed used for data storage
B	Analog-to-digital converter sample width in bits
C	Anti-aliasing input filter bandwidth
D	CPU register width in bits

18. - E4D01

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

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

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which are constant at all IF levels
B	Signals which have a sharply peaked frequency distribution
C	Signals which appear across a wide bandwidth
D	Signals which appear at one IF but not another

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

21. - E5B10

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

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

22. - E5C03

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

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

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	1.73
C	1.414
D	0.5

24. - E6A10

In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	5
B	2
C	4
D	6

25. - E6B13

What type of bias is required for an LED to emit light?

Select	Answer
A	Reverse bias
B	Forward bias
C	Zero bias
D	Inductive bias

26. - E6C12

What is BiCMOS logic?

Select	Answer
A	A logic device with two CMOS circuits per package
B	A logic family based on bismuth CMOS devices
C	An integrated circuit logic family using both bipolar and CMOS transistors
D	A FET logic family based on bimetallic semiconductors

27. - E6D04

Which materials are commonly used as a slug core in a variable inductor?

Select	Answer
A	Cobalt and aluminum
B	Teflon and Delrin
C	Ferrite and brass
D	Polystyrene and polyethylene

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

29. - E6F05

Which describes an optical shaft encoder?

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

30. - E7A12

What type of logic defines "0" as a high voltage?

Select	Answer
A	Assertive Logic
B	Negative logic
C	Reverse Logic
D	Positive Logic

31. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A high-pass filter to compensate for low gain at low frequencies
B	A low-pass filter to remove switching signal components
C	A temperature compensating load resistor to improve linearity
D	A matched load resistor to prevent damage by switching transients

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Lower losses
B	Higher efficiency
C	Greater transformation range
D	Greater harmonic suppression

33. - E7D16

When several electrolytic filter capacitors are connected in series to increase the operating voltage of a power supply filter circuit, why should resistors be connected across each capacitor?

Select	Answer
A	To provide a minimum load current to reduce voltage excursions at light loads
B	To equalize, as much as possible, the voltage drop across each capacitor
C	To provide a safety bleeder to discharge the capacitors when the supply is off
D	All of these choices are correct

34. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By driving a product detector with a DSB signal
B	By using a reactance modulator followed by a mixer
C	By using a balanced modulator followed by a filter
D	By using a loop modulator followed by a mixer

35. - E7F12

What digital process is applied to I and Q signals in order to recover the baseband modulation information?

Select	Answer
A	Fast Fourier Transform
B	Quadrature mixing
C	Signal conditioning
D	Decimation

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As a high-pass filter used to block RFI at the input to receivers
B	As a low-pass filter used between a transmitter and a transmission line
C	As an audio filter in a receiver
D	For smoothing power supply output

37. - E7H01

What are three oscillator circuits used in Amateur Radio equipment?

Select	Answer
A	Pierce, Fenner and Beane
B	Taft, Pierce and negative feedback
C	Taft, Hartley and Pierce
D	Colpitts, Hartley and Pierce

38. - E8A12

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

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

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital mode for narrow band, slow speed transmissions
B	A bandwidth compression technique using Fourier transforms
C	A frequency modulation technique which uses non-harmonically related frequencies
D	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It has more possible states than simple binary
B	It has more resolution than simple binary
C	It increases security
D	It facilitates error detection

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

Select	Answer
A	+10 dB
B	-20 dB
C	-30 dB
D	+15 dB

42. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Take-off angle
B	Distance from the transmitter
C	The standing wave ratio
D	Soil conductivity

43. - E9B05

What type of antenna pattern over real ground is shown in Figure E9-2?

Select	Answer
A	Polarization
B	Elevation
C	Azimuth
D	Radiation resistance

44. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

Select	Answer
A	The main lobe takeoff angle decreases in the downhill direction
B	The main lobe takeoff angle increases in the downhill direction
C	The horizontal beam width decreases in the downhill direction
D	The horizontal beam width increases in the uphill direction

45. - E9D07

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

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

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

47. - E9F16

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has higher velocity factor
B	All of these choices are correct
C	Foam dielectric has lower safe operating voltage limits
D	Foam dielectric has lower loss per unit of length

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage circles and current arcs
B	Voltage lines and current chords
C	Resistance lines and reactance chords
D	Resistance circles and reactance arcs

49. - E9H05

What is the main drawback of a wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF bands
B	It receives equally well in all directions
C	It is non-rotatable
D	It has a bidirectional pattern

50. - E0A10

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

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

Figure E6-2

Figure E9-2