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7D15: Difference between revisions
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{{Spec | Input impedance | 1 MΩ // 22 pF }} | {{Spec | Input impedance | 1 MΩ // 22 pF }} | ||
{{EndSpecs}} | {{EndSpecs}} | ||
==Links== | ==Links== | ||
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* [https://www.youtube.com/watch?v=K6NqQur7iHU Tektronix 7D15 Repair and alignment] by Zenwizard Studios @ YouTube | * [https://www.youtube.com/watch?v=K6NqQur7iHU Tektronix 7D15 Repair and alignment] by Zenwizard Studios @ YouTube | ||
{{Documents|Link=7D15}} | {{Documents|Link=7D15}} | ||
==Internals== | |||
The 7D15 uses a number of Tek-made custom chips. The [[155-0086-00]], [[155-0087-00]] and [[155-0088-00]] legend generators are specific to this plug-in. The [[155-0090-00]] or [[155-0171-00]] four decade counter/latch/DAC chips implement the lower six counter digits. For the topmost two digits, the 7D15 employs ECL counters. ECL logic requires a −5 V supply, which a switching regulator (board A8) generates from the −15 V rail. | |||
The 5 MHz signal from the (non-ovenized) internal reference crystal oscillator is divided down to a 1 MHz master clock. Optionally, the 1 MHz can be supplied externally as well. An internal VCO, phase-locked to the 1 MHz master, produces a 100 MHz input to the counter chain for timing measurements. | |||
==Prices== | ==Prices== | ||