Sub-Element T7 Station equipment: common transmitter and receiver problems, antenna measurements, troubleshooting, basic repair & testing [4 Exam Questions] Flashcards
Which term describes the ability of a receiver to detect the presence of a signal?
Sensitivity
What is a transceiver?
A unit combining the functions of a transmitter and a receiver
Which of the following is used to convert a radio signal from one frequency to another?
Mixer
Which term describes the ability of a receiver to discriminate between multiple signals?
Selectivity
What is the name of a circuit that generates a signal at a specific frequency?
Oscillator
What device converts the RF input and output of a transceiver to another band?
Transverter
What is meant by “PTT”?
The push-to-talk function that switches between receive and transmit
Which of the following describes combining speech with an RF carrier signal?
Modulation
What is the function of the SSB/CW-FM switch on a VHF power amplifier?
Set the amplifier for proper operation in the selected mode
What device increases the low-power output from a handheld transceiver?
An RF power amplifier
Where is an RF preamplifier installed?
Between the antenna and receiver
What can you do if you are told your FM handheld or mobile transceiver is over-deviating?
Talk farther away from the microphone
What would cause a broadcast AM or FM radio to receive an amateur radio transmission unintentionally?
The receiver is unable to reject strong signals outside the AM or FM band
Which of the following can cause radio frequency interference?
All of these choices are correct
Which of the following is a way to reduce or eliminate interference from an amateur transmitter to a nearby telephone?
Put an RF filter on the telephone
How can overload of a non-amateur radio or TV receiver by an amateur signal be reduced or eliminated?
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?
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 to a VHF transceiver from a nearby FM broadcast station?
Band-reject filter
What should you do if something in a neighbor’s home is causing harmful interference to your amateur station?
All of these choices are correct
What is a Part 15 device?
An unlicensed device that may emit low-powered radio signals on frequencies used by a licensed service
What might be a problem if you receive a report that your audio signal through the repeater is distorted or unintelligible?
All of these choices are correct
What is a symptom of RF feedback in a transmitter or transceiver?
Reports of garbled, distorted, or unintelligible voice transmissions
What should be the first step to resolve cable TV interference from your ham radio transmission?
Be sure all TV coaxial connectors are installed properly
What is the primary purpose of a dummy load?
To prevent transmitting signals over the air when making tests
Which of the following instruments can be used to determine if an antenna is resonant at the desired operating frequency?
An antenna analyzer
What, in general terms, is standing wave ratio (SWR)?
A measure of how well a load is matched to a transmission line
What reading on an SWR meter indicates a perfect impedance match between the antenna and the feed line?
1 to 1
Why do most solid-state amateur radio transmitters reduce output power as SWR increases?
To protect the output amplifier transistors
What does an SWR reading of 4:1 indicate?
Impedance mismatch
What happens to power lost in a feed line?
It is converted into heat
What instrument other than an SWR meter could you use to determine if a feed line and antenna are properly matched?
Directional wattmeter
Which of the following is the most common cause for failure of coaxial cables?
Moisture contamination
Why should the outer jacket of coaxial cable be resistant to ultraviolet light?
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?
It requires special techniques to prevent water absorption
What does a dummy load consist of?
A non-inductive resistor and a heat sink
Which instrument would you use to measure electric potential or electromotive force?
A voltmeter
What is the correct way to connect a voltmeter to a circuit?
In parallel with the circuit
How is a simple ammeter connected to a circuit?
In series with the circuit
Which instrument is used to measure electric current?
An ammeter
What instrument is used to measure resistance?
An ohmmeter
Which of the following might damage a multimeter?
Attempting to measure voltage when using the resistance setting
Which of the following measurements are commonly made using a multimeter?
Voltage and resistance
Which of the following types of solder is best for radio and electronic use?
Rosin-core solder
What is the characteristic appearance of a cold solder joint?
A grainy or dull surface
What is probably happening when an ohmmeter, connected across an unpowered circuit, initially indicates a low resistance and then shows increasing resistance with time?
The circuit contains a large capacitor
Which of the following precautions should be taken when measuring circuit resistance with an ohmmeter?
Ensure that the circuit is not powered
Which of the following precautions should be taken when measuring high voltages with a voltmeter?
Ensure that the voltmeter and leads are rated for use at the voltages to be measured
