View source for R7912

{{Oscilloscope Sidebar 
|manufacturer=Tektronix 
|series=7000-series scopes
|model=R7912
|summary=500 MHz digitizer
|image=USA Tek R7912 FrontWork.jpg 
|caption=Tektronix R7912AD with a modern monitor
|introduced=1973 
|discontinued=1978 
|designers=Carlo Infante;Jim Cavoretto;Al Allworth;Don Roberts;Stu McNaughton;Walt Lowy;Ray Hayes;Ken Hawken;Bob Culter;Hal Cobb;Ed Ritz;Bo Janko
|manuals=
* [[Media:070-1590-00.pdf|Tektronix R7912 Service Manual]]
* [[Media:070-1888-00.pdf|1350 (aka 067-0679-00) Memory Display Unit for R7912]]
* [[Media:Waveform Digitizing Instruments (R7912).pdf|Waveform Digitizing Instruments (R7912) Brochure]]
* [[Media:tek_7912_and_related_digitizer_docs.pdf|7912 and related digitizer documents]]
{{ROM Images}}
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}}
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.

{{MissingSpecs}}

==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|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==
* [https://www.radiomuseum.org/forum/tektronix_r7912_transient_digitizer.html Tek R7912 @ radiomuseum.org]
* [[Media:Tek retiree news 2012 11 nov.pdf|Hale Farley, ''The introduction of the R7912'']] in Tek Retirees Newsletter 11/2012
* [[Patent US 3748585A|US Patent 3748585: ''Silicon Diode Array Scan Converter Tube and Method of Operation''.  Culter et al, July 1973.]]
* [[Media:Rochester LLE Review Volume 25.pdf|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)"''
* [[Media:Lockheed report-lmsc-d628276.pdf|Lockheed Palo Alto Research Lab study for LLL (June 1978)]] describing the LM7912 Enhanced Performance Transient Digitizer, claiming 3 GHz bandwidth
* [[Media:Boyer data acq ebeam fus acc.pdf|William B. Boyer, ''Data Acquisition and Processing on Electron Beam Fusion Accelerators''. IEEE Transactions on Nuclear Science Vol.NS-25, No. 1, February 1978]]
* [https://cds.cern.ch/record/2828791/files/MPS-LIN-Note-75-8.pdf Pulsed Laser Measurements Using The R7912 Transient Digitizer: app note 47N1.1] (app note begins on pg 12)

{{Documents|Link=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==

<gallery>
USA Tek R7912 FrontWork.jpg  |   R7912 connected to a modern video monitor. Note 7000-style readout.
R7912 1.jpg | R7912 front
R7912 2.jpg | R7912 controls
R7912 3.jpg | R7912 rear
Tek wp2000 2.jpg|067-0679-00 front next to [[608]] monitor
Tek wp2000 3.jpg|067-0679-00 rear next to [[608]] monitor
Tek wp2000 1.jpg|067-0679-00 detail
067-0679-00.jpg |067-0679-00 aka [[1350]]
</gallery>

==Components==
{{Parts|R7912}}
{{Custom ICs|7000 series readout system}}

[[Category:7000 series digitizer mainframes]]
[[Category:Scan converter based instruments]]

[[Category:GPIB interface]]