Subelement L: L – Installation, Maintenance & Repair— Topic 77: Specialized Instruments
Question 3-77L2
Element 3 (GROL)What does the horizontal axis of a spectrum analyzer display?
Explanation
A spectrum analyzer's fundamental purpose is to display the distribution of signal power as a function of frequency. Therefore, the horizontal axis (x-axis) represents the range of frequencies being analyzed. Operators set the start and stop frequencies, or a center frequency and span, to observe the spectral content within that band.
Options A (Amplitude) and B (Voltage) are incorrect because these quantities, representing the strength or power level of the signals, are displayed on the vertical axis (y-axis) of a spectrum analyzer. Option C (Resonance) is a characteristic of a circuit or antenna at a specific frequency, not a direct axis display. While a spectrum analyzer can help identify a resonant frequency by showing a peak in power, the axis itself still displays frequency.
Related Questions
3-76L6 What instrument is used to check the signal quality of a single-sideband radio transmission?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).3-77L3 What does the vertical axis of a spectrum analyzer display?3-77L4 What instrument is most accurate when checking antennas and transmission lines at the operating frequency of the antenna?3-77L5 What test instrument can be used to display spurious signals in the output of a radio transmitter?