T7 – PRACTICAL CIRCUITS – [4 Exam Questions - 4 Groups] Flashcards
“Which term describes the ability of a receiver to detect the presence of a signal?”
A. Linearity
B. Sensitivity
C. Selectivity
D. Total Harmonic Distortion
B. Sensitivity
“What is a transceiver?”
A. A device that combines a receiver and transmitter
B. A device for matching feed line impedance to 50 ohms
C. A device for automatically sending and decoding Morse code
D. A device for converting receiver and transmitter frequencies to another band
A. A device that combines a receiver and transmitter
“Which of the following is used to convert a signal from one frequency to another?”
A. Phase splitter
B. Mixer
C. Inverter
D. Amplifier
B. Mixer
“Which term describes the ability of a receiver to discriminate between multiple signals?”
A. Discrimination ratio
B. Sensitivity
C. Selectivity
D. Harmonic distortion
C. Selectivity
“What is the name of a circuit that generates a signal at a specific frequency?”
A. Reactance modulator
B. Phase modulator
C. Low-pass filter
D. Oscillator
D. Oscillator
“What device converts the RF input and output of a transceiver to another band?”
A. High-pass filter
B. Low-pass filter
C. Transverter
D. Phase converter
C. Transverter
“What is the function of a transceiver’s PTT input?”
A. Input for a key used to send CW
B. Switches transceiver from receive to transmit when grounded
C. Provides a transmit tuning tone when grounded
D. Input for a preamplifier tuning tone
B. Switches transceiver from receive to transmit when grounded
“Which of the following describes combining speech with an RF carrier signal?”
A. Impedance matching
B. Oscillation
C. Modulation
D. Low-pass filtering
C. Modulation
“What is the function of the SSB/CW-FM switch on a VHF power amplifier?”
A. Change the mode of the transmitted signal
B. Set the amplifier for proper operation in the selected mode
C. Change the frequency range of the amplifier to operate in the proper segment of the band
D. Reduce the received signal noise
B. Set the amplifier for proper operation in the selected mode
“What device increases the transmitted output power from a transceiver?”
A. A voltage divider
B. An RF power amplifier
C. An impedance network
D. All these choices are correct
B. An RF power amplifier
“Where is an RF preamplifier installed?”
A. Between the antenna and receiver
B. At the output of the transmitter power amplifier
C. Between the transmitter and the antenna tuner
D. At the output of the receiver audio amplifier
A. Between the antenna and receiver
“What can you do if you are told your FM handheld or mobile transceiver is over-deviating?”
A. Talk louder into the microphone
B. Let the transceiver cool off
C. Change to a higher power level
D. Talk farther away from the microphone
D. Talk farther away from the microphone
“What would cause a broadcast AM or FM radio to receive an amateur radio transmission unintentionally?”
A. The receiver is unable to reject strong signals outside the AM or FM band
B. The microphone gain of the transmitter is turned up too high
C. The audio amplifier of the transmitter is overloaded
D. The deviation of an FM transmitter is set too low
A. The receiver is unable to reject strong signals outside the AM or FM band
“Which of the following can cause radio frequency interference?”
A. Fundamental overload
B. Harmonics
C. Spurious emissions
D. All these choices are correct
D. All these choices are correct
“Which of the following could you use to cure distorted audio caused by RF current on the shield of a microphone cable?”
A. Band-pass filter
B. Low-pass filter
C. Preamplifier
D. Ferrite choke
D. Ferrite choke
“How can fundamental overload of a non-amateur radio or TV receiver by an amateur signal be reduced or eliminated?”
A. Block the amateur signal with a filter at the antenna input of the affected receiver
B. Block the interfering signal with a filter on the amateur transmitter
C. Switch the transmitter from FM to SSB
D. Switch the transmitter to a narrow-band mode
A. Block the amateur signal with a filter at the antenna input of the affected receiver
“Which of the following actions should you take if a neighbor tells you that your station’s transmissions are interfering with their radio or TV reception?”
A. Make sure that your station is functioning properly and that it does not cause interference to your own radio or television when it is tuned to the same channel
B. Immediately turn off your transmitter and contact the nearest FCC office for assistance
C. Install a harmonic doubler on the output of your transmitter and tune it until the interference is eliminated
D. All these choices are correct
A. Make sure that your station is functioning properly and that it does not cause interference to your own radio or television when it is tuned to the same channel
“Which of the following can reduce overload of a VHF transceiver by a nearby commercial FM station?”
A. Installing an RF preamplifier
B. Using double-shielded coaxial cable
C. Installing bypass capacitors on the microphone cable
D. Installing a band-reject filter
D. Installing a band-reject filter
“What should you do if something in a neighbor’s home is causing harmful interference to your amateur station?”
A. Work with your neighbor to identify the offending device
B. Politely inform your neighbor that FCC rules prohibit the use of devices that cause interference
C. Make sure your station meets the standards of good amateur practice
D. All these choices are correct
D. All these choices are correct
“What should be the first step to resolve non-fiber optic cable TV interference caused by your amateur radio transmission?”
A. Add a low-pass filter to the TV antenna input
B. Add a high-pass filter to the TV antenna input
C. Add a preamplifier to the TV antenna input
D. Be sure all TV feed line coaxial connectors are installed properly
D. Be sure all TV feed line coaxial connectors are installed properly
“What might be a problem if you receive a report that your audio signal through an FM repeater is distorted or unintelligible?”
A. Your transmitter is slightly off frequency
B. Your batteries are running low
C. You are in a bad location
D. All these choices are correct
D. All these choices are correct
“What is a symptom of RF feedback in a transmitter or transceiver?”
A. Excessive SWR at the antenna connection
B. The transmitter will not stay on the desired frequency
C. Reports of garbled, distorted, or unintelligible voice transmissions
D. Frequent blowing of power supply fuses
C. Reports of garbled, distorted, or unintelligible voice transmissions
“What is the primary purpose of a dummy load?”
A. To prevent transmitting signals over the air when making tests
B. To prevent over-modulation of a transmitter
C. To improve the efficiency of an antenna
D. To improve the signal-to-noise ratio of a receiver
A. To prevent transmitting signals over the air when making tests
“Which of the following is used to determine if an antenna is resonant at the desired operating frequency?”
A. A VTVM
B. An antenna analyzer
C. A Q meter
D. A frequency counter
B. An antenna analyzer
“What does a dummy load consist of?”
A. A high-gain amplifier and a TR switch
B. A non-inductive resistor mounted on a heat sink
C. A low-voltage power supply and a DC relay
D. A 50-ohm reactance used to terminate a transmission line
B. A non-inductive resistor mounted on a heat sink
“What reading on an SWR meter indicates a perfect impedance match between the antenna and the feed line?”
A. 50:50
B. Zero
C. 1:1
D. Full Scale
C. 1:1
“Why do most solid-state transmitters reduce output power as SWR increases beyond a certain level?”
A. To protect the output amplifier transistors
B. To comply with FCC rules on spectral purity
C. Because power supplies cannot supply enough current at high SWR
D. To lower the SWR on the transmission line
A. To protect the output amplifier transistors
“What does an SWR reading of 4:1 indicate?”
A. Loss of -4 dB
B. Good impedance match
C. Gain of +4 dB
D. Impedance mismatch
D. Impedance mismatch
“What happens to power lost in a feed line?”
A. It increases the SWR
B. It is radiated as harmonics
C. It is converted into heat
D. It distorts the signal
C. It is converted into heat
“Which instrument can be used to determine SWR? “
A. Voltmeter
B. Ohmmeter
C. Iambic pentameter
D. Directional wattmeter
D. Directional wattmeter
“Which of the following causes failure of coaxial cables?”
A. Moisture contamination
B. Solder flux contamination
C. Rapid fluctuation in transmitter output power
D. Operation at 100% duty cycle for an extended period
A. Moisture contamination
“Why should the outer jacket of coaxial cable be resistant to ultraviolet light?”
A. Ultraviolet resistant jackets prevent harmonic radiation
B. Ultraviolet light can increase losses in the cable’s jacket
C. Ultraviolet and RF signals can mix, causing interference
D. Ultraviolet light can damage the jacket and allow water to enter the cable
D. Ultraviolet light can damage the jacket and allow water to enter the cable
“What is a disadvantage of air core coaxial cable when compared to foam or solid dielectric types?”
A. It has more loss per foot
B. It cannot be used for VHF or UHF antennas
C. It requires special techniques to prevent moisture in the cable
D. It cannot be used at below freezing temperatures
C. It requires special techniques to prevent moisture in the cable
“Which instrument would you use to measure electric potential?”
A. An ammeter
B. A voltmeter
C. A wavemeter
D. An ohmmeter
B. A voltmeter
“How is a voltmeter connected to a component to measure applied voltage?”
A. In series
B. In parallel
C. In quadrature
D. In phase
B. In parallel
“When configured to measure current, how is a multimeter connected to a component?”
A. In series
B. In parallel
C. In quadrature
D. In phase
A. In series
“Which instrument is used to measure electric current?”
A. An ohmmeter
B. An electrometer
C. A voltmeter
D. An ammeter
D. An ammeter
“Which of the following measurements are made using a multimeter?”
A. Signal strength and noise
B. Impedance and reactance
C. Voltage and resistance
D. All these choices are correct
C. Voltage and resistance
“Which of the following types of solder should not be used for radio and electronic applications?”
A. Acid-core solder
B. Lead-tin solder
C. Rosin-core solder
D. Tin-copper solder
A. Acid-core solder
“What is the characteristic appearance of a cold tin-lead solder joint?”
A. Dark black spots
B. A bright or shiny surface
C. A rough or lumpy surface
D. Excessive solder
C. A rough or lumpy surface
“What reading indicates that an ohmmeter is connected across a large, discharged capacitor?”
A. Increasing resistance with time
B. Decreasing resistance with time
C. Steady full-scale reading
D. Alternating between open and short circuit
A. Increasing resistance with time
“Which of the following precautions should be taken when measuring in-circuit resistance with an ohmmeter?”
A. Ensure that the applied voltages are correct
B. Ensure that the circuit is not powered
C. Ensure that the circuit is grounded
D. Ensure that the circuit is operating at the correct frequency
B. Ensure that the circuit is not powered
