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7A42: Difference between revisions
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The '''Tektronix 7A42''' is a four-channel 350 MHz plug-in for [[7000-series scopes]]. | The '''Tektronix 7A42''' is a four-channel 350 MHz plug-in for [[7000-series scopes]]. It is a double-wide plug-in, with signal outputs and mainframe readout only using the left slot. | ||
It was specifically designed for logic signals (TTL, ECL, CMOS) and supports triggering based on Boolean conditions of the four inputs. | It was specifically designed for logic signals (TTL, ECL, CMOS) and supports triggering based on Boolean conditions of the four inputs. | ||
A fifth trace, "Trigger View", displays the trigger function output or external clock input. | |||
A | There are two sets of conditions, A and B, that can be individually selected or paired in an "A then B" mode called ''nested triggering'', where the occurrence of condition A arms the trigger and condition B causes the trigger to be generated. | ||
The trigger can be qualified by an external clock. A trigger filter control, variable from 0-300 ns, allows events shorter than the selected length to be suppressed. A TTL-level "reset" input will inhibit the trigger if active. | |||
Selected by an internal jumper, either the trigger signal, or the "A then B" interval, is available on a front-panel trigger output. This can e.g. be routed a counter for time measurement or event counting. | |||
Tektronix recommended the [[P6131]], | The input V/Div setting can only be seen in the mainframe's readout. There is a jumper to allow the readout to work in a [[7854]] mainframe. | ||
The trigger level is set digitally and shown on a 7-segment display. | |||
Tektronix recommended the [[P6131]], 300 MHz, 10 MΩ ×10 probe, and the [[P6230]], 1.5 GHz, 450/50 Ω ×10, variable-offset probe for ECL circuits. | |||
The [[067-1155-99]] calibration fixture is specific to the 7A42. | The [[067-1155-99]] calibration fixture is specific to the 7A42. | ||
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There is a [[7A42/Repairs|NiCd backup battery]] that allows the unit to retain its last configuration. | There is a [[7A42/Repairs|NiCd backup battery]] that allows the unit to retain its last configuration. | ||
A 555 timer implements a 15 ms "real-time clock" and watchdog reset, another drives a beeper. | |||
==See also== | ==See also== | ||