3.9 KiB
3.9 KiB
T7B – Symptoms, causes, and cures of common transmitter and receiver problems: overload and overdrive, distortion, interference and consumer electronics, RF feedback
- T7B01 (D)
What can you do if you are told your FM handheld or mobile transceiver is over-deviating? #card
- A. Talk louder into the microphone
- B. Let the transceiver cool off
- C. Change to a higher power level
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D. Talk farther away from the microphone
- T7B02 (A)
What would cause a broadcast AM or FM radio to receive an amateur radio transmission unintentionally? #card
- 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
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D. The deviation of an FM transmitter is set too low
- T7B03 (D)
Which of the following can cause radio frequency interference? #card
- A. Fundamental overload
- B. Harmonics
- C. Spurious emissions
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D. All these choices are correct
- T7B04 (D)
Which of the following could you use to cure distorted audio caused by RF current on the shield of a microphone cable? #card
- A. Band-pass filter
- B. Low-pass filter
- C. Preamplifier
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D. Ferrite choke
- T7B05 (A)
How can fundamental overload of a non-amateur radio or TV receiver by an amateur signal be reduced or eliminated? #card
- 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
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D. Switch the transmitter to a narrow-band mode
- T7B06 (A)
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? #card
- 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
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D. All these choices are correct
- T7B07 (D)
Which of the following can reduce overload of a VHF transceiver by a nearby commercial FM station? #card
- A. Installing an RF preamplifier
- B. Using double-shielded coaxial cable
- C. Installing bypass capacitors on the microphone cable
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D. Installing a band-reject filter
- T7B08 (D)
What should you do if something in a neighbor’s home is causing harmful interference to your amateur station? #card
- 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
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D. All these choices are correct
- T7B09 (D)
What should be the first step to resolve non-fiber optic cable TV interference caused by your amateur radio transmission? #card
- 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
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D. Be sure all TV feed line coaxial connectors are installed properly
- T7B10 (D)
What might be a problem if you receive a report that your audio signal through an FM repeater is distorted or unintelligible? #card
- A. Your transmitter is slightly off frequency
- B. Your batteries are running low
- C. You are in a bad location
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D. All these choices are correct
- T7B11 (C)
What is a symptom of RF feedback in a transmitter or transceiver? #card
- 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