7D12

Manuals – Specifications – Links – Pictures

The Tektronix 7D12 is an A/D converter (digital meter) plug-in for 7000-series scopes. The A/D converter can be triggered internally (when installed in a horizontal bay), manually by a front panel switch, or externally from a trigger source. The 7D12 will trigger automatically at approximately 4 Hz if set to Auto. It contains a vertical display amplifier that displays the signal being applied to the module and a gate display amplifier that displays a representation of the 7D12 internal gate signal.

The 7D12 accepts plug-in modules M1, M2, or M3.

• M1 is a digital multimeter module with DC voltage, resistance and temperature (with P6058) ranges. It does not produce an analog output signal.
• M2 is a sample and hold module that can measure voltage from ground to a selected point, or the difference voltage between two points defined by a trigger signal. When triggered by the delayed gate signal from a time base, this allows cursor-like measurements to be made. The module has an aperture time of only 10 ns. With repetitive signals, the period between the sampled points can be as short as 30 ns, in single shot mode it must be at least 150 μs.
  Input sensitivity is selectable between ±2 V (100/200/500 mV/Div) and ±20 V (1/2/5 V/Div) ranges. The input has a ring to detect a ×10 probe with readout pin (P6055 recommended) and adjusts the display accordingly. Signal bandwidth is 25 MHz.
• M3 is a True RMS module with floating inputs. It produces an analog output signal with a 3 dB bandwidth of 700 kHz and vertical sensitivities between 100 mV/Div to 500 V/Div in a 1−2−5 sequence. The RMS converter is implemented with opamps and transistords from a CA3046 array.
• 067-0700-00 is a calibration fixture.

Links

• TekScope Vol. 7 No. 5, 1975 p.15+: Dave McCullough, Delayed gate aids oscilloscope digital measurements

Pictures

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  7D12 with M2 Sample and Hold Module

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  7D12 with M1, M2 and M3

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  7D12 without plug-in, left side

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  7D12 without plug-in, right side

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  7D12 with M2 plug-in, left side

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  7D12 with M2 plug-in, right side

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  067-0700-00 calibration plug-in

M1

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  M1 plug-in, front

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  M1 plug-in, rear

M2

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  M2 front

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  M2 plug-in, left side

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  M2 plug-in, right side

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  7D12/M2 displaying sawtooth from 585 (lower trace), triggered with delayed gate output from a 7B53A (intensified).

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  "Master Sampler" cartoon in schematic

M3

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  M3 plug-in, front

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  M3 plug-in, rear

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