The HP Model 8565A Spectrum Analyzer provides a visual display of RF signals in the frequency domain. Input signal amplitude is plotted on the CRT as a function of frequency. The HP Model 8565A is designed for simplicity of operation. Most measurements can be made using only three controls once the green Normal Settings have been preset. The Model 8565A has absolute amplitude and frequency calibration from 10 MHz to 22 GHz. The frequency span, bandwidth, and video filter are all coupled with automatic sweep to maintain a calibrated display and simplify operation of the analyzer. Internal preselection eliminates most spurious responses to simplify signal identification. The preselector also extends dynamic range of the analyzer as well as provides some protection for the input mixer. All major spectrum analyzer parameters are displayed on the CRT bezel readout. The frequency range of the HP Model 8565A is 10 MHz to 22 GHz in direct coaxial input and 14.5 to 40 GHz when used with the HP Model 11517A External Mixer.