FCC Technician Class Exam Study Guide - 2014-2018/Subelement T7 Group B

Common transmitter and receiver problems: symptoms of overload and overdrive; distortion; causes of interference; interference and consumer electronics; part 15 devices; over and under modulation; RF feedback; off frequency signals; fading and noise; problems with digital communications interfaces

The Question Pool

Question 1

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

The correct answer is D.

Question 2

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

The correct answer is A.

Question 3

Which of the following may be a cause of radio frequency interference?

A. Fundamental overload

B. Harmonics

C. Spurious emissions

D. All of these choices are correct

The correct answer is D.

Question 4

Which of the following is a way to reduce or eliminate interference by an amateur transmitter to a nearby telephone?

A. Put a filter on the amateur transmitter

B. Reduce the microphone gain

C. Reduce the SWR on the transmitter transmission line

D. Put a RF filter on the telephone

The correct answer is D.

Question 5

How can 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

The correct answer is A.

Question 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?

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. Tell them that your license gives you the right to transmit and nothing can be done to reduce the interference

D. Install a harmonic doubler on the output of your transmitter and tune it until the interference is eliminated

The correct answer is A.

Question 7

Which of the following may be useful in correcting a radio frequency interference problem?

A. Snap-on ferrite chokes

B. Low-pass and high-pass filters

C. Band-reject and band-pass filters

D. All of these choices are correct

The correct answer is D.

Question 8

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 about the rules that prohibit the use of devices which cause interference

C. Check your station and make sure it meets the standards of good amateur practice

D. All of these choices are correct

The correct answer is D.

Question 9

What is a Part 15 device?

A. An unlicensed device that may emit low powered radio signals on frequencies used by a licensed service

B. A type of amateur radio that can legally be used in the citizen's band

C. A device for long distance communications using special codes sanctioned by the International Amateur Radio Union

D. A type of test set used to determine whether a transmitter is in compliance with FCC regulation 91.15

The correct answer is A

Question 10

What might be the problem if you receive a report that your audio signal through the repeater is distorted or unintelligible?

A. Your transmitter may be slightly off frequency

B. Your batteries may be running low

C. You could be in a bad location

D. All of these choices are correct

The correct answer is D.

Question 11

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 transmissions

D. Frequent blowing of power supply fuses

The correct answer is C.

Question 12

What might be the first step to resolve cable TV interference from your ham 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 coaxial connectors are installed properly

The correct answer is D.