Key Topic 77: Specialized Instruments

Question 1

3-77L1: A(n) ___ and ___ can be combined to measure the characteristics of transmission lines. Such an arrangement is known as a time-domain reflectometer (TDR).

A. Frequency spectrum analyzer, RF generator.
B. Oscilloscope, pulse generator.
C. AC millivolt meter, AF generator.
D. Frequency counter, linear detector.

Answer 1

B. Oscilloscope, pulse generator.

Question 2

3-77L2: What does the horizontal axis of a spectrum analyzer display?

A. Amplitude.
B. Voltage.
C. Resonance.
D. Frequency.

Answer 2

D. Frequency.

Question 3

3-77L3: What does the vertical axis of a specrtum analyzer display?

A. Amplitude.
B. Duration.
C. Frequency.
D. Time.

Answer 3

A. Amplitude.

Question 4

3-77L4: What instrument is most accurate when checking antennas and transmission lines at the operating frequency of the antenna?

A. Time domain reflectometer.
B. Wattmeter.
C. DMM.
D. Frequency domain reflectometer.

Answer 4

D. Frequency domain reflectometer.

Question 5

3-77L5: What test instrument can be used to display spurious signals in the output of a radio transmitter?

A. A spectrum analyzer.
B. A wattmeter.
C. A logic analyzer.
D. A time domain reflectometer.

Answer 5

A. A spectrum analyzer.

Question 6

3-77L6: What instrument is commonly used by radio service technicians to monitor frequency, modulation, check receiver sensitivity, distortion, and to generate audio tones?

A. Oscilloscope.
B. Spectrum analyzer.
C. Service monitor.
D. DMM.

Answer 6

C. Service monitor.