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. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operators of all the stations in the system not authenticating the source from which they accept communications
B	The control operator of the originating station
C	The control operators of all the stations in the system
D	The control operator of the packet bulletin board station

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	30 miles
B	1 mile
C	3 miles
D	10 miles

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	A control operator need not be present at the control point
B	Only Extra Class operators may be the control operator of a remote station
C	A control operator must be present at the control point
D	Repeater and auxiliary stations may not be remotely controlled

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
B	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
C	All HF bands
D	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands

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	Send the application form to the FCC and inform the FCC of the grade
C	Destroy the application form
D	Return the application document to the examinee

6. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When neither the amateur nor his or her employer has a pecuniary interest in the communications
B	When transmitting international third-party communications
C	When the total money involved does not exceed $25
D	When the control operator is employed by the FCC or another government agency

7. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	A linearly polarized antenna
B	A circularly polarized antenna
C	An isotropic antenna
D	A log-periodic dipole array

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

9. - E2C01

Which of the following is true about contest operating?

Select	Answer
A	Every contest requires a signal report in the exchange
B	Interference to other amateurs is unavoidable and therefore acceptable
C	Operators are permitted to make contacts even if they do not submit a log
D	It is mandatory to transmit the call sign of the station being worked as part of every transmission to that station

10. - E2D09

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	170 Hz shift, 45 baud RTTY
B	AMTOR
C	300 baud packet
D	PSK31

11. - E2E03

How is the timing of JT65 contacts organized?

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

12. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The D layer
B	The F1 layer
C	The F2 layer
D	The E layer

13. - E3B11

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

Select	Answer
A	Any time
B	Around sunrise
C	Early evening
D	Around sunset

14. - E3C13

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

Select	Answer
A	Vertical
B	Elliptical
C	Horizontal
D	Circular

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	RF amplitude and time
C	SWR and time
D	SWR and frequency

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S11
B	S22
C	S21
D	S12

17. - E4C10

Which of the following is a desirable amount of selectivity for an amateur RTTY HF receiver?

Select	Answer
A	100 Hz
B	2400 Hz
C	6000 Hz
D	300 Hz

18. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.34 MHz and 146.61 MHz
B	146.88 MHz and 146.34 MHz
C	173.35 MHz and 139.40 MHz
D	146.10 MHz and 147.30 MHz

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	The audio frequency bandwidth of the received signal might be compressed
C	FM signals can no longer be demodulated
D	Received audio in the speech range might have an echo effect

20. - E5A11

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	157.8 Hz
B	315.6 Hz
C	23.67 kHz
D	47.3 kHz

21. - E5B04

What is the time constant of a circuit having two 220 microfarad capacitors and two 1 megohm resistors, all in parallel?

Select	Answer
A	220 seconds
B	55 seconds
C	440 seconds
D	110 seconds

22. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By real and imaginary parts
B	By X and R values
C	By phase angle and amplitude
D	By Y and G values

23. - E5D14

What is reactive power?

Select	Answer
A	Power lost because of capacitor leakage
B	Power consumed in circuit Q
C	Power consumed in wire resistance in an inductor
D	Wattless, nonproductive power

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	Corner frequency
B	Alpha cutoff frequency
C	Beta cutoff frequency
D	Alpha rejection frequency

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Enhanced carrier retention time
B	Much higher reverse voltage breakdown
C	Less forward voltage drop
D	Controlled reverse avalanche voltage

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	Larger bypass capacitors are used in CMOS circuit design
B	Input signals are stronger
C	The input switching threshold is about two times the power supply voltage
D	The input switching threshold is about one-half the power supply voltage

27. - E6D12

What is the definition of saturation in a ferrite core inductor?

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

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	-10 dB
B	2 dB
C	44 dBm
D	-20 dBm

29. - E6F07

What is a solid state relay?

Select	Answer
A	A mechanical relay that latches in the on or off state each time it is pulsed
B	A device that uses semiconductors to implement the functions of an electromechanical relay
C	A relay using transistors to drive the relay coil
D	A passive delay line

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. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Fixed bias
B	Load resistors
C	Self bias
D	Feedback

32. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Gradual passband rolloff with minimal stop band ripple
B	Gradual passband rolloff with extreme stop band ripple
C	Extremely flat response over its pass band with gradually rounded stop band corners
D	Extremely sharp cutoff with one or more notches in the stop band

33. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A shunt current source
B	A series regulator
C	A series current source
D	A shunt regulator

34. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable inductance or capacitance
B	To produce AM signals by using an electrically variable inductance or capacitance
C	To produce AM signals by using an electrically variable resistance
D	To produce PM signals by using an electrically variable resistance

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Change the gain by a factor of 3/4
B	Multiply each sample value by a factor of 3/4
C	Interpolate by a factor of three, then decimate by a factor of four
D	Add 3 to each input value and subtract 4 from each output value

36. - E7G03

What is the typical input impedance of an integrated circuit op-amp?

Select	Answer
A	100 ohms
B	Very low
C	1000 ohms
D	Very high

37. - E7H01

What are three oscillator circuits used in Amateur Radio equipment?

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

38. - E8A08

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

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

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
B	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
C	Two or more signals are quadrature modulated to increase bandwidth efficiency
D	Two or more signals are arranged to share discrete time slots of a data transmission

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

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Excessive numbers of retries
B	Bit errors in the modem
C	Excessive transmit audio levels
D	Ground loops

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

43. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	1
B	4
C	3
D	7

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	450 ohms
B	300 ohms
C	72 ohms
D	50 ohms

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

Select	Answer
A	It must be neutralized
B	It is too sharply directional at lower frequencies
C	It radiates the harmonics and fundamental equally well
D	It might radiate harmonics

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 transform the antenna impedance to a higher value
C	To provide a rejection notch that prevents the radiation of harmonics
D	To cancel the inductive reactance of the matching network

47. - E9F15

What impedance does a 1/2 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	Very high impedance
B	Very low impedance
C	The same as the characteristic impedance of the line
D	The same as the output impedance of the generator

48. - 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

49. - E9H11

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

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

50. - E0A10

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

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

Figure E7-1

Figure E9-2