Technician T7B: Interference and audio problems
These are the 11 official questions in group T7B of the 2026–2030 Technician question pool, with the correct answer marked and a plain-English explanation of why it's right. The real exam asks one question from this group.
- T7B01Question 1
What can you do if you are told your FM handheld or mobile transceiver is over-deviating?
- ATalk louder into the microphone
- BLet the transceiver cool off
- CChange to a higher power level
- DTalk farther away from the microphone Correct
Why: Over-deviation means your audio is too strong, so talk farther from the mic.
- T7B02Question 2
What would cause a broadcast AM or FM radio to receive an amateur radio transmission unintentionally?
- AThe receiver is unable to reject strong signals outside the AM or FM band Correct
- BThe microphone gain of the transmitter is turned up too high
- CThe audio amplifier of the transmitter is overloaded
- DThe deviation of an FM transmitter is set too low
Why: The receiver can't reject a strong signal from outside its band, so it picks you up.
- T7B03Question 3
Which of the following can cause radio frequency interference?
- AFundamental overload
- BHarmonics
- CSpurious emissions
- DAll these choices are correct Correct
Why: Fundamental overload, harmonics and spurious emissions can all cause RFI.
- T7B04Question 4
Which of the following might be the cause of low RF power output from a solid-state transceiver?
- APoor amplifier noise figure
- BPoor amplifier linearity
- CLow SWR
- DHigh SWR Correct
Why: High SWR makes a solid-state transceiver cut its power to protect itself.
- T7B05Question 5
Which of the following might reduce interference by an amateur station to a non-amateur over-the-air radio receiver?
- ABlock the amateur signal with a filter at the antenna input of the affected receiver Correct
- BBlock the interfering signal with a filter on the amateur transmitter
- CSwitch the transmitter from FM to SSB
- DSwitch the transmitter to a narrow-band mode
Why: A filter at the affected receiver's antenna input blocks your signal from it.
- T7B06Question 6
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?
- AMake 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 Correct
- BImmediately turn off your transmitter and contact the nearest FCC office for assistance
- CInstall a harmonic doubler on the output of your transmitter and tune it until the interference is eliminated
- DAll these choices are correct
Why: First make sure your station works properly and doesn't interfere with your own radio or TV on the same channel.
- T7B07Question 7
Which of the following can reduce interference to a 2-meter band transceiver from a nearby commercial FM station?
- AInstalling an RF preamplifier
- BUsing double-shielded coaxial cable
- CInstalling bypass capacitors on the microphone cable
- DInstalling a band-reject filter Correct
Why: A band-reject filter blocks the strong FM broadcast signal from your 2-meter radio.
- T7B08Question 8
What should you do if something in a neighbor’s home is causing harmful interference to your amateur station?
- AWork with your neighbor to identify the offending device
- BPolitely inform your neighbor that FCC rules prohibit the use of devices that cause interference
- CMake sure your station meets the standards of good amateur practice
- DAll these choices are correct Correct
Why: Explain the problem politely, cooperate with your neighbor, and know they must fix a device causing harmful interference. All the choices are correct.
- T7B09Question 9
What should be the first step to resolve non-fiber optic cable TV interference caused by your amateur radio transmission?
- AAdd a low-pass filter to the TV antenna input
- BAdd a high-pass filter to the TV antenna input
- CAdd a preamplifier to the TV antenna input
- DBe sure all TV feed line coaxial connectors are installed properly Correct
Why: Loose or bad coax connectors let RF into cable TV systems, so check those first.
- T7B10Question 10
What might be a problem if you receive a report that your audio signal through an FM repeater is distorted or unintelligible?
- AYour transmitter is slightly off frequency
- BYou are speaking too loudly or too close to the microphone
- CYou are in a bad location
- DAll these choices are correct Correct
Why: A weak battery, being too far from the repeater, or RF in your radio can each distort your audio.
- T7B11Question 11
Which of the following can eliminate distorted voice transmissions?
- AAdding extra feedline to the antenna to lower SWR
- BTurning the radio on and off to reset the computer-controlled circuitry
- CAdding a clip-on ferrite “choke” to the microphone cable to prevent the transmitted signal from feeding back into the transmitter Correct
- DTurning the squelch control fully clockwise to prevent the transmitted signal from triggering the squelch circuit
Why: A ferrite choke on the mic cable stops RF from feeding back into the transmitter.