E8A01
What type of wave is made up of a sine wave plus all of its odd harmonics?
A. A square wave
B. A sine wave
C. A cosine wave
D. A tangent wave
E8A02
What type of wave has a rise time significantly faster than its fall time (or vice versa)?
A. A cosine wave
B. A square wave
C. A sawtooth wave
D. A sine wave
E8A03
What type of wave is made up of sine waves of a given fundamental frequency plus all its harmonics?
A. A sawtooth wave
B. A square wave
C. A sine wave
D. A cosine wave
E8A04
What is the equivalent to the root-mean-square value of an AC voltage?
A. The AC voltage found by taking the square of the average value of the peak AC voltage
B. The DC voltage causing the same amount of heating in a given resistor as the corresponding peak AC voltage
C. The DC voltage causing the same amount of heating in a resistor as the corresponding RMS AC voltage
D. The AC voltage found by taking the square root of the average AC value
E8A05
What would be the most accurate way of measuring the RMS voltage of a complex waveform?
A. By using a grid dip meter
B. By measuring the voltage with a D'Arsonval meter
C. By using an absorption wavemeter
D. By measuring the heating effect in a known resistor
E8A06
What is the approximate ratio of PEP-to-average power in a typical voice-modulated single-sideband phone signal?
A. 2.5 to 1
B. 25 to 1
C. 1 to 1
D. 100 to 1
E8A07
What determines the PEP-to-average power ratio of a single-sideband phone signal?
A. The frequency of the modulating signal
B. The characteristics of the modulating signal
C. The degree of carrier suppression
D. The amplifier gain
E8A08
What is the period of a wave?
A. The time required to complete one cycle
B. The number of degrees in one cycle
C. The number of zero crossings in one cycle
D. The amplitude of the wave
E8A09
What type of waveform is produced by human speech?
A. Sinusoidal
B. Logarithmic
C. Irregular
D. Trapezoidal
E8A10
Which of the following is a distinguishing characteristic of a pulse waveform?
A. Regular sinusoidal oscillations
B. Narrow bursts of energy separated by periods of no signal
C. A series of tones that vary between two frequencies
D. A signal that contains three or more discrete tones
E8A11
What is one use for a pulse modulated signal?
A. Linear amplification
B. PSK31 data transmission
C. Multiphase power transmission
D. Digital data transmission
E8A12
What type of information can be conveyed using digital waveforms?
A. Human speech
B. Video signals
C. Data
D. All of these answers are correct
E8A13
What is an advantage of using digital signals instead of analog signals to convey the same information?
A. Less complex circuitry is required for digital signal generation and detection
B. Digital signals always occupy a narrower bandwidth
C. Digital signals can be regenerated multiple times without error
D. All of these answers are correct
E8A14
Which of these methods is commonly used to convert analog signals to digital signals?
A. Sequential sampling
B. Harmonic regeneration
C. Level shifting
D. Phase reversal
E8A15
What would the waveform of a digital data stream signal look like on a conventional oscilloscope?
A. A series of sine waves with evenly spaced gaps
B. A series of pulses with varying patterns
C. A running display of alpha-numeric characters
D. None of the above; this type of signal cannot be seen on a conventional oscilloscope
E8B01
What is the term for the ratio between the frequency deviation of an RF carrier wave, and the modulating frequency of its corresponding FM-phone signal?
A. FM compressibility
B. Quieting index
C. Percentage of modulation
D. Modulation index
E8B02
How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)
?
A. It increases as the RF carrier frequency increases
B. It decreases as the RF carrier frequency increases
C. It varies with the square root of the RF carrier frequency
D. It does not depend on the RF carrier frequency
E8B03
What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency, when the modulating frequency is 1000 Hz?
A. 3
B. 0.3
C. 3000
D. 1000
E8B04
What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2-kHz modulating frequency?
A. 6000
B. 3
C. 2000
D. 1/3
E8B05
What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz and accepting a maximum modulation rate of 3 kHz?
A. 60
B. 0.167
C. 0.6
D. 1.67
E8B06
What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz and accepting a maximum modulation frequency of 3.5 kHz?
A. 2.14
B. 0.214
C. 0.47
D. 47
E8B07
When using a pulse-width modulation system, why is the transmitter's peak power greater than its average power?
A. The signal duty cycle is less than 100%
B. The signal reaches peak amplitude only when voice modulated
C. The signal reaches peak amplitude only when voltage spikes are generated within the modulator
D. The signal reaches peak amplitude only when the pulses are also amplitude modulated
E8B08
What parameter does the modulating signal vary in a pulse-position modulation system?
A. The number of pulses per second
B. The amplitude of the pulses
C. The duration of the pulses
D. The time at which each pulse occurs
E8B09
How are the pulses of a pulse-modulated signal usually transmitted?
A. A pulse of relatively short duration is sent; a relatively long period of time separates each pulse
B. A pulse of relatively long duration is sent; a relatively short period of time separates each pulse
C. A group of short pulses are sent in a relatively short period of time; a relatively long period of time separates each group
D. A group of short pulses are sent in a relatively long period of time; a relatively short period of time separates each group
E8B10
What is meant by deviation ratio?
A. The ratio of the audio modulating frequency to the center carrier frequency
B. The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
C. The ratio of the carrier center frequency to the audio modulating frequency
D. The ratio of the highest audio modulating frequency to the average audio modulating frequency
E8B11
Which of these methods can be used to combine several separate analog information streams into a single analog radio frequency signal?
A. Frequency shift keying
B. A diversity combiner
C. Frequency division multiplexing
D. Pulse compression
E8B12
Which of the following describes frequency division multiplexing?
A. The transmitted signal jumps from band to band at a predetermined rate
B. Two or more information streams are merged into a "baseband", which then modulates the transmitter
C. The transmitted signal is divided into packets of information
D. Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
E8B13
What is time division multiplexing?
A. Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
B. Two or more signals are arranged to share discrete time slots of a digital data transmission
C. Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
D. Two or more signals are quadrature modulated to increase bandwidth efficiency
E8C01
Which one of the following digital codes consists of elements having unequal length?
A. ASCII
B. AX.25
C. Baudot
D. Morse code
E8C02
What are some of the differences between the Baudot digital code and ASCII?
A. Baudot uses four data bits per character, ASCII uses seven; Baudot uses one character as a shift code, ASCII has no shift code
B. Baudot uses five data bits per character, ASCII uses seven; Baudot uses two characters as shift codes, ASCII has no shift code
C. Baudot uses six data bits per character, ASCII uses seven; Baudot has no shift code, ASCII uses two characters as shift codes
D. Baudot uses seven data bits per character, ASCII uses eight; Baudot has no shift code, ASCII uses two characters as shift codes
E8C03
What is one advantage of using the ASCII code for data communications?
A. It includes built-in error-correction features
B. It contains fewer information bits per character than any other code
C. It is possible to transmit both upper and lower case text
D. It uses one character as a shift code to send numeric and special characters
***** E8C04 This question has been removed by the QPC
E8C05
What technique is used to minimize the bandwidth requirements of a PSK-31 signal?
A. Zero-sum character encoding
B. Reed-Solomon character encoding
C. Use of sinusoidal data pulses
D. Use of trapezoidal data pulses
E8C06
What is the necessary bandwidth of a 13-WPM international Morse code transmission?
A. Approximately 13 Hz
B. Approximately 26 Hz
C. Approximately 52 Hz
D. Approximately 104 Hz
E8C07
What is the necessary bandwidth of a 170-hertz shift, 300-baud ASCII transmission?
A. 0.1 Hz
B. 0.3 kHz
C. 0.5 kHz
D. 1.0 kHz
E8C08
What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?
A. 15.36 kHz
B. 9.6 kHz
C. 4.8 kHz
D. 5.76 kHz
E8C09
What term describes a wide-bandwidth communications system in which the transmitted carrier frequency varies according to some predetermined sequence?
A. Amplitude compandored single sideband
B. AMTOR
C. Time-domain frequency modulation
D. Spread-spectrum communication
E8C10
Which of these techniques causes a digital signal to appear as wide-band noise to a conventional receiver?
A. Spread-spectrum
B. Independent sideband
C. Regenerative detection
D. Exponential addition
E8C11
What spread-spectrum communications technique alters the center frequency of a conventional carrier many times per second in accordance with a pseudo-random list of channels?
A. Frequency hopping
B. Direct sequence
C. Time-domain frequency modulation
D. Frequency compandored spread-spectrum
E8C12
What spread-spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?
A. Frequency hopping
B. Direct sequence
C. Binary phase-shift keying
D. Phase compandored spread-spectrum
E8C13
What makes spread-spectrum communications resistant to interference?
A. Interfering signals are removed by a frequency-agile crystal filter
B. Spread-spectrum transmitters use much higher power than conventional carrier-frequency transmitters
C. Spread-spectrum transmitters can hunt for the best carrier frequency to use within a given RF spectrum
D. Only signals using the correct spreading sequence are received
E8C14
What is the advantage of including a parity bit with an ASCII character stream?
A. Faster transmission rate
B. The signal can overpower interfering signals
C. Foreign language characters can be sent
D. Some types of errors can be detected
E8C15
What is one advantage of using JT-65 coding?
A. Uses only a 65 Hz bandwidth
B. Virtually perfect decoding of signals well below the noise
C. Easily copied by ear if necessary
D. Permits fast-scan TV transmissions over narrow bandwidth
E8D01[was E8D02 edited]
What is the easiest voltage amplitude parameter to measure when viewing a pure sine wave signal on an oscilloscope?
A. Peak-to-peak voltage
B. RMS voltage
C. Average voltage
D. DC voltage
E8D02
What is the relationship between the peak-to-peak voltage and the peak voltage amplitude of a symmetrical waveform?
A. 0.707:1
B. 2:1
C. 1.414:1
D. 4:1
E8D03
What input-amplitude parameter is valuable in evaluating the signal-handling capability of a Class A amplifier?
A. Peak voltage
B. RMS voltage
C. Average power
D. Resting voltage
E8D04
What is the PEP output of a transmitter that has a maximum peak of 30 volts to a 50-ohm load as observed on an oscilloscope?
A. 4.5 watts
B. 9 watts
C. 16 watts
D. 18 watts
E8D05
If an RMS-reading AC voltmeter reads 65 volts on a sinusoidal waveform, what is the peak-to-peak voltage?
A. 46 volts
B. 92 volts
C. 130 volts
D. 184 volts
E8D06
What is the advantage of using a peak-reading wattmeter to monitor the output of a SSB phone transmitter?
A. It is easier to determine the correct tuning of the output circuit
B. It gives a more accurate display of the PEP output when modulation is present
C. It makes it easier to detect high SWR on the feed-line
D. It can determine if any "flat-topping" is present during modulation peaks
E8D07
What is an electromagnetic wave?
A. Alternating currents in the core of an electromagnet
B. A wave consisting of two electric 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 consisting of two magnetic fields at right angles to each other
E8D08
Which of the following best describes electromagnetic waves traveling in free space?
A. Electric and magnetic fields become aligned as they travel
B. The energy propagates through a medium with a high refractive index
C. The waves are reflected by the ionosphere and return to their source
D. Changing electric and magnetic fields propagate the energy
E8D09
What is meant by circularly polarized electromagnetic waves?
A. Waves with an electric field bent into a circular shape
B. Waves with a rotating electric field
C. Waves that circle the Earth
D. Waves produced by a loop antenna
E8D10
What is the polarization of an electromagnetic wave if its magnetic field is parallel to the surface of the Earth?
A. Circular
B. Horizontal
C. Elliptical
D. Vertical
E8D11
What is the polarization of an electromagnetic wave if its magnetic field is perpendicular to the surface of the Earth?
A. Horizontal
B. Circular
C. Elliptical
D. Vertical
E8D12
At approximately what speed do electromagnetic waves travel in free space?
A. 300 million meters per second
B. 186,300 meters per second
C. 186,300 feet per second
D. 300 million miles per second
E8D13
What type of meter should be used to monitor the output signal of a voice-modulated single-sideband transmitter to ensure you do not exceed the maximum allowable power?
A. An SWR meter reading in the forward direction
B. A modulation meter
C. An average reading wattmeter
D. A peak-reading wattmeter
E8D14
What is the average power dissipated by a 50-ohm resistive load during one complete RF cycle having a peak voltage of 35 volts?
A. 12.2 watts
B. 9.9 watts
C. 24.5 watts
D. 16 watts
E8D15
If an RMS reading voltmeter reads 34 volts on a sinusoidal waveform, what is the peak voltage?
A. 123 volts
B. 96 volts
C. 55 volts
D. 48 volts
E8D16
Which of the following is a typical value for the peak voltage at a common household electrical outlet?
A. 240 volts
B. 170 volts
C. 120 volts
D. 340 volts
E8D17
Which of the following is a typical value for the peak-to-peak voltage at a common household electrical outlet?
A. 240 volts
B. 120 volts
C. 340 volts
D. 170 volts
E8D18
Which of the following is a typical value for the RMS voltage at a common household electrical power outlet?
A. 120-V AC
B. 340-V AC
C. 85-V AC
D. 170-V AC
E8D19
What is the RMS value of a 340-volt peak-to-peak pure sine wave?
A. 120-V AC
B. 170-V AC
C. 240-V AC
D. 300-V AC