E4 - AMATEUR PRACTICES [5 Exam Questions - 5 Groups] 60 Questions Flashcards
“Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope? “
A. Sampling rate of the analog-to-digital converter
B. Amount of memory
C. Q of the circuit
D. All these choices are correct
A. Sampling rate of the analog-to-digital converter
“Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?”
A. RF amplitude and time
B. RF amplitude and frequency
C. SWR and frequency
D. SWR and time
B. RF amplitude and frequency
“Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?”
A. A wattmeter
B. A spectrum analyzer
C. A logic analyzer
D. A time-domain reflectometer
B. A spectrum analyzer
“How is the compensation of an oscilloscope probe typically adjusted?”
A. A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
B. A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
C. A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
D. A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
A. A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
“What is the purpose of the prescaler function on a frequency counter?”
A. It amplifies low-level signals for more accurate counting
B. It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
C. It prevents oscillation in a low-frequency counter circuit
D. It divides a higher frequency signal so a low-frequency counter can display the input frequency
D. It divides a higher frequency signal so a low-frequency counter can display the input frequency
“What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?”
A. A false, jittery low-frequency version of the signal is displayed
B. All signals will have a DC offset
C. Calibration of the vertical scale is no longer valid
D. Excessive blanking occurs, which prevents display of the signal
A. A false, jittery low-frequency version of the signal is displayed
“Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?”
A. Antenna analyzers automatically tune your antenna for resonance
B. Antenna analyzers do not need an external RF source
C. Antenna analyzers display a time-varying representation of the modulation envelope
D. All these choices are correct
B. Antenna analyzers do not need an external RF source
“Which of the following measures SWR?”
A. A spectrum analyzer
B. A Q meter
C. An ohmmeter
D. An antenna analyzer
D. An antenna analyzer
“Which of the following is good practice when using an oscilloscope probe?”
A. Keep the signal ground connection of the probe as short as possible
B. Never use a high-impedance probe to measure a low-impedance circuit
C. Never use a DC-coupled probe to measure an AC circuit
D. All these choices are correct
A. Keep the signal ground connection of the probe as short as possible
“Which of the following displays multiple digital signal states simultaneously?”
A. Network analyzer
B. Bit error rate tester
C. Modulation monitor
D. Logic analyzer
D. Logic analyzer
“How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?”
A. Loosely couple the analyzer near the antenna base
B. Connect the analyzer via a high-impedance transformer to the antenna
C. Loosely couple the antenna and a dummy load to the analyzer
D. Connect the antenna feed line directly to the analyzer’s connector
D. Connect the antenna feed line directly to the analyzer’s connector
“Which of the following factors most affects the accuracy of a frequency counter?”
A. Input attenuator accuracy
B. Time base accuracy
C. Decade divider accuracy
D. Temperature coefficient of the logic
B. Time base accuracy
“What is the significance of voltmeter sensitivity expressed in ohms per volt?”
A. The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
B. When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
C. When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
D. When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
A. The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
“Which S parameter is equivalent to forward gain?”
A. S11
B. S12
C. S21
D. S22
C. S21
“Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?”
A. S11
B. S12
C. S21
D. S22
A. S11
“What three test loads are used to calibrate an RF vector network analyzer?”
A. 50 ohms, 75 ohms, and 90 ohms
B. Short circuit, open circuit, and 50 ohms
C. Short circuit, open circuit, and resonant circuit
D. 50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
B. Short circuit, open circuit, and 50 ohms
“How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?”
A. 100 watts
B. 125 watts
C. 25 watts
D. 75 watts
D. 75 watts
“What do the subscripts of S parameters represent?”
A. The port or ports at which measurements are made
B. The relative time between measurements
C. Relative quality of the data
D. Frequency order of the measurements
A. The port or ports at which measurements are made
“Which of the following can be used to measure the Q of a series-tuned circuit?”
A. The inductance to capacitance ratio
B. The frequency shift
C. The bandwidth of the circuit’s frequency response
D. The resonant frequency of the circuit
C. The bandwidth of the circuit’s frequency response
“What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?”
A. There is possibly a short to ground in the feed line
B. The transmitter is not properly neutralized
C. There is an impedance mismatch between the antenna and feed line
D. There is more power going into the antenna
D. There is more power going into the antenna
“Which of the following methods measures intermodulation distortion in an SSB transmitter?”
A. Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
B. Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
C. Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
D. Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
B. Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
“Which of the following can be measured with a vector network analyzer?”
A. Input impedance
B. Output impedance
C. Reflection coefficient
D. All these choices are correct
D. All these choices are correct
“What is an effect of excessive phase noise in a receiver’s local oscillator?”
A. It limits the receiver’s ability to receive strong signals
B. It can affect the receiver’s frequency calibration
C. It decreases receiver third-order intercept point
D. It can combine with strong signals on nearby frequencies to generate interference
D. It can combine with strong signals on nearby frequencies to generate interference
“Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?”
A. A front-end filter or pre-selector
B. A narrow IF filter
C. A notch filter
D. A properly adjusted product detector
A. A front-end filter or pre-selector