7B80 Features The 7B80 Time-Base unit provides calibrated sweep rates from 5 seconds to 10 nanoseconds and triggering to 400 megahertz for 7700-, 7800-, and 7900-series oscilloscopes. A X10 Magnifier increases each sweep rate by a factor of 10 and a VARIABLE TIME/DIV control provides continuously variable sweep rates between calibrated steps. Variable hold off and alphanumeric readout are provided. Also, when operating in the AUTO TRIGGERING MODE, a bright baseline trace is displayed in the absence of a trigger signal. The 7B80 can be operated as an independent time base or as a delayed-sweep unit with a companion delaying time-base unit.