The HP Model 8554B Spectrum analyzer RF Section covers the frequency range from 100 kHz to 1250 MHz. When it is combined with an IF Section and a Display Section it functions as the tuning section of an RF spectrum analyzer. The analyzer electronically scans input signals and displays their frequency and amplitude on a CRT. The horizontal, x-axis, is calibrated in units of frequency and the vertical, y-axis, is calibrated in absolute units of voltage (/j.V or mV) or power (dBm). Absolute or relative measurements of both amplitude and frequency can be easily made.