A wideband sampling voltmeter

A high accuracy sampling voltmeter, designed to span the frequency range of 10 Hz to 200 MHz, is described. The instrument operates autonomously, at a measurement update rate of at least one per second. A novel quasi-equivalent time sampling process is used, with a custom strobed comparator as the sampling device and decision element. The architecture and control are presented, along with the time-base design principles. Major error sources associated with the time-base are also discussed.