7B87 FEATURES The 7B87 Time-Base unit Pretrigger Acquire Clock provides calibrated sweep rates from 5 seconds lo 10 nanoseconds and triggering to 400 megahertz (or 7000 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 holdoff 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 7B87 can be operated as an independent time base or as a delayed-sweep unit with a companion delaying time-base unit Sweep mode is determined by the companion delaying time base The 7B87 also features an internally-generated clock and an external clock input for sequential single sweep acquisition when operating in a 7000 series digitizing oscilloscope The frequency range of the internally generated clock is 20 48 mHz (millihertz) to 20 48 MHz as determined by the TIME DIV. X10 MAG. and INT - 1000 switches Also, an ACOUIRE-STOP DELAY function varies delay pickoff. and therefore pretrigger time, in compatible digitizing plug-in oscilloscopes The portion of the oscilloscope real time display between the triggering event and the end of delay time is intensified The exact delay time is displayed on the crt readout