Minimum Input Threshold 50 mV for lower-level discriminator. Input impedance 2000 W . FINE GAIN Single-turn potentiometer for direct reading, continuous adjustment of Fine Gain factor from 0.5 to 2.5. Factory set at 50 s. When the LL Ref mode switch on the rear panel is in the Ext position, this control is ineffective.
Output occurs as leading edge of linear input crosses the window threshold.