I have an HP 86290B with option H08. The frequency of this sweep oscillator plug goes from 2 GHz to 22 GHz. However, the frequency reference from the BNC connector on the back of the unit only goes up to a maximum of 18.8 volts when measured using my DVM. I thought it was supposed to produce an output of about 1 volt/GHz so that the voltage should go up to 22.0 volts? I checked the output frequency, however, and it does go to 22 GHz at the end of the scale.
Later sweepers allowed you to select either 1V/GHz or 0.5V/GHz, but that change had not happened for the 86290B plug-in. Is this really causing a problem? It was only used in a few applications...