5B40: Difference between revisions
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The '''Tektronix 5B40''' is a 60 MHz timebase for [[5000-series scopes]], particularly the 5400-series. | The '''Tektronix 5B40''' is a 60 MHz timebase for [[5000-series scopes]], particularly the 5400-series. | ||
{{MissingSpecs}} | |||
==Internals== | |||
The trigger signal passes through source switching, coupling switching, and then a JFET source-follower buffer. | The trigger signal passes through source switching, coupling switching, and then a JFET source-follower buffer. | ||
Next, the signal is buffered by a PNP emitter-follower biased at around 5mA collector current. | Next, the signal is buffered by a PNP emitter-follower biased at around 5mA collector current. | ||
That provides a known (low) source impedance for driving the switch-selectable LF reject and HF reject filters. | That provides a known (low) source impedance for driving the switch-selectable LF reject and HF reject filters. | ||
The output of the filters drives a discrete NPN differential amplifier, which drives U165, a [[155-0109-01]] Tek-made trigger IC. | The output of the filters drives a discrete NPN differential amplifier, which drives U165, a [[155-0109-01]] Tek-made trigger IC. | ||
==Pictures== | ==Pictures== | ||