542 Linear Gate and Stretcher

• For passing and blocking analog signals in the range from +0.1 to +10 V
• Ungated or gated with coincidence or anticoincidence gating
• Strobed linear output with internal or external strobe
• Adjustable output delay and width

The ORTEC Model 542 Linear Gate and Stretcher accepts a linear input pulse through an input linear gate, stretches the peak amplitude of the input pulse, and generates an output pulse with amplitude equal to the input, and shaped to a uniform rise time and width. It is useful for selecting and inhibiting linear signals according to chosen coincidence or timing conditions. The Model 542 features excellent temperature stability, integral linearity, response to high counting rates, and simplicity of operation. In addition, the Linear Gate section features total dc-coupling with essentially zero pedestal and feedthrough.

Each linear input pulse must exceed the adjustable discriminator level to enable generation of an output pulse. The linear output pulse has a fixed rise time, a 100:1 dynamic range, an adjustable width, and is delayed by an adjustable interval (0.5–5 µs) after the peak of the linear input pulse. Operating in either coincidence or anticoincidence mode, the input linear gate can be disabled or enabled for an adjustable gate period following a Gate Input logic pulse. A switch-selectable external strobe input permits strobing the output during an adjustable interval (5–50 µs) after the input pulse peak. A slide switch on the front panel permits selection of any one of three input connections: DC Couple, BLR Low, or BLR High. These features make the Model 542 suitable for inclusion directly after the linear amplifier in a system.

The pulse from a Busy Output on the rear panel indicates the time duration from the peak of a Linear Input pulse until the end of the output pulse, as set by the pulse Width control, or until the input discriminator has been reset, whichever is longer. This output can be counted in a scaler to indicate how many pulses are furnished through the system, or it can be integrated to indicate relative dead time.

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