Tektronix 7B53A Here is the easy-to-use 7B53A Dual

Here is the easy-to-use 7B53A Dual Time Base Plug-in, compatible with 7000-Series mainframes. This time base will trigger to 100MHz and has normal, intensified delaying, delayed, and mixed sweep modes. Delaying sweep speeds are 50 ns to 5 s/div in 25 steps (calibrated) and at least 2.5 times the calibrated sweep rate, continuously variable between steps (uncalibrated). Other very useful functions are X10 MAG, INT. and EXT. (main & delayed) trigger inputs, single sweep, front-panel Cal and fine/coarse position controls. The unit is recommended for use with 7313 and 7600-Mainframes.