1-9. GENERAL. The @ Model 185B Oscilloscope provides a visual display of very high-speed phenomena with repetition rates to 1000 mc. The instrument will present a steady display of pulse repetition rates below 100 kc even when the signals are randomly spaced. For frequencies above 100 kc, the incoming signal is divided down so that the input circuitry will operate reliably. As the input frequency increases above 100 kc, more uniform spacing is required to obtain jitter-free presentation.