R7912

Manuals – Specifications – Links – Pictures

The Tektronix R7912, introduced in September 1973, is a digitizer that achieved a bandwidth of 500 MHz with a 7A19 vertical amplifier plug-in. It was also possible, like in the 7904 scope, to access the CRT deflection plates directly through a 7A21N plug-in and achieve a bandwidth of 1 GHz, albeit at reduced sensitivity (4 V/Div) and loss of triggering and readout functions. Some customers further modified the stock 7912 to increase bandwidth up to 3 GHz in special applications (see literature links below).

The 7912AD replaced the R7912 in 1978.

Key Specifications

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Internals

The reading beam operates differently depending on the output mode. In TV mode, the reading beam scans the target in a horizontal format similar to that used in conventional television systems, and a video output compatible with TV monitors is generated. In Digital mode, the reading beam scans the target vertically, in 512 discrete steps for each of 512 horizontal positions. Waveforms are converted to digital, stored in memory, and can be read by a computer.

The R7912 used the 7000 series readout system writing readout characters onto the storage target, which would become part of the output signal in the NON STORE mode.

The R7912 had a proprietary digital interface. A card for interfacing to a DEC PDP-11 was available, among other options. The Tektronix 067-0679-00 aka 1350 Digital Display Controller or "Memory Display Unit" is an external module that interfaces the R7912 to X-Y monitors. Tek also offered configurations with multiple R7912s on a common controller within the WP2000 series.

Links

• Tek R7912 @ radiomuseum.org
• Hale Farley, The introduction of the R7912 in Tek Retirees Newsletter 11/2012
• US Patent 3748585: Silicon Diode Array Scan Converter Tube and Method of Operation. Culter et al, July 1973.
• University of Rochester LLE Review, Oct-Dec 1985 mentioning the LM7912A, a Lockheed-modified R7912 variant having "a bandwidth of 3.5 GHz at the -3 dB point, less than 5% undershoot and overshoot, with a 12-bit output (2 mV/bit)"
• Lockheed Palo Alto Research Lab study for LLL (June 1978) describing the LM7912 Enhanced Performance Transient Digitizer, claiming 3 GHz bandwidth
• William B. Boyer, Data Acquisition and Processing on Electron Beam Fusion Accelerators. IEEE Transactions on Nuclear Science Vol.NS-25, No. 1, February 1978
• Pulsed Laser Measurements Using The R7912 Transient Digitizer: app note 47N1.1 (app note begins on pg 12)

Documents Referencing R7912

Document	Class	Title	Authors	Year	Links
Tekscope 1973 V5 N6 Nov 1973.pdf	Article	Digitizing and displaying fast pulses	Hale Farley	1973	R7912
Tekscope 1973 V5 N6 Nov 1973.pdf	Article	A New Way to Look At Transients	Carlo Infante	1973	R7912
Data Acquisition and Processing on Electron Beam Fusion Accelerators - William Boyer 1978.pdf	Article	DATA ACQUISITION AND PROCESSING ON ELECTRON BEAM FUSION ACCELERATORS	William B. Boyer	1978	R7912 • 4010 • 4610 • 4631 • 1340
Lockheed report-lmsc-d628276.pdf	Article	Enhanced Performance Transient Digitizer, the LM7912		1978	LM7912 • R7912
Tek retiree news 2012 11 nov.pdf	Article	Tektronix R7912 Programmable Transient Waveform Digitizer	Hale Farley	2012	R7912

See Also

• 7912AD, 7912HB
• WP2051, WP2052
• MP1101
• SCD1000, SCD5000
• 670-6466-00 7912 AD plug-in interface extender
• 067-0854-00 Calibration Kit
• 067-0679-99 R7912 Demo Unit

Pictures

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  R7912 connected to a modern video monitor. Note 7000-style readout.

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  R7912 front

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  R7912 controls

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  R7912 rear

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  067-0679-00 front next to 608 monitor

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  067-0679-00 rear next to 608 monitor

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  067-0679-00 detail

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  067-0679-00 aka 1350

Components

Some Parts Used in the R7912

Custom ICs used in the 7000 series readout system

Page	Model	Part nos	Description	Designers	Used in
155-0014-01	M019D	155-0014-00 • 155-0014-01	analog-to-decimal converter	Barrie Gilbert	7000 series readout system • 7854 • 7934 • 7J20 • 7L5 • P7001
155-0015-01	M020F	155-0015-00 • 155-0015-01	analog data switch	Barrie Gilbert	7000 series readout system • 7854 • 7934
155-0017-00	M025	155-0017-00	5 MHz decade counter	Barrie Gilbert	7000 series readout system • 7854 • 7934
155-0018-00	M026	155-0018-00	zeros logic control	Les Larson	7000 series readout system • 7934
155-0019-00	M027	155-0019-00	decimal point and spacing control	Les Larson	7000 series readout system
155-0020-00	M028	155-0020-00	output assembler	Les Larson	7000 series readout system
155-0021-00	M029C	155-0021-00 • 155-0021-01	timing generator	Les Larson	7000 series readout system • 7854 • 7934
155-0023-00	M160	155-0023-00	character generator (0 1 2 3 4 5 6 7 8 9)	Barrie Gilbert	7000 series readout system
155-0024-00	M161	155-0024-00	character generator (↓ < I / + - + C Δ >)	Barrie Gilbert	7000 series readout system
155-0025-00	M162	155-0025-00	character generator (m μ n p X K M G T R)	Barrie Gilbert	7000 series readout system
155-0026-00	M163	155-0026-00	character generator (S V A W H d B c Ω E)	Barrie Gilbert	7000 series readout system
155-0027-00	M164	155-0027-00	character generator (U N L Z Y P F J Q D)	Barrie Gilbert	7000 series readout system