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{{Oscilloscope Sidebar|
{{Oscilloscope Sidebar  
title=Tektronix 7912|
|manufacturer=Tektronix
image=Tek-7912ad.jpg|
|series=7000-series scopes
caption=Tektronix 7912AD with [[7A26]] and [[7B90P]] |
|model=7912
introduced=1973 |
|summary=500/750 MHz digitizer
discontinued=1989 |
|image=Tek-7912ad.jpg
summary=500/750 MHz Digitizer|
|caption=Tektronix 7912AD with [[7A26]] and [[7B90P]]  
manuals=
|introduced=1973  
'''R7912'''
|discontinued=1989  
* [[Media:R7912 070-1590-00.pdf|Tektronix R7912 Service Manual (PDF)]]
|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
* [[Media:1350 070-1888-00.pdf|1350 (AKA 067-0679-00) Memory Display Unit for R7912 (PDF)]]
|manuals=
* [[Media:Waveform Digitizing Instruments (R7912).pdf|Waveform Digitizing Instruments (R7912) Brochure (PDF)]]
* ''see individual model pages''
* [http://w140.com/tek_7912_and_related_digitizer_docs.pdf 7912 and related digitizer documents]
'''7912AD/HB'''
* [[Media:7912ad_theory.pdf | 7912AD Operator's Manual (partial, 57 pages from introduction)]]
* [http://w140.com/7912ad_reading_gun_supply.pdf 7912AD Video preamp/Reading gun supply schematics]
* [http://w140.com/7912ad_writing_gun_supply.pdf 7912AD Z-Axis/HV board schematics]
* [[Media:070-5077-00.pdf|Tektronix 7912AD Instrument Interfacing Guide (PDF)]]
}}
}}
The '''Tektronix 7912''' is a series of high-speed digitizers that take one [[7000-series_plug-ins#Vertical plug-ins|7000-series vertical plug-in]]  
The '''Tektronix 7912''' is a series of high-speed digitizers that take one [[7000-series_plug-ins#Vertical plug-ins|7000-series vertical plug-in]]  
and one [[7000-series_plug-ins#Horizontal plug-ins|7000-series horizontal plug-in]].   
and one [[7000-series_plug-ins#Horizontal plug-ins|7000-series horizontal plug-in]].  The primary markets for the 7912 series were nuclear and laser research.   


All 7912 models use the same internal CRT-based, digitizing [[scan converter]] tube ([[T7912]]) that is not visible from the outside.  
All 7912 models use the same internal CRT-based, digitizing [[scan converter]] tube ([[T7912]], 154-0698-00) that is not visible from the outside.  
The signal from the vertical plug-in deflects a writing beam through [[distributed deflection plates]].  
The signal from the vertical plug-in deflects a writing beam through [[distributed deflection plates]].  
The electrons hit a small flat rectangular solid state target, conceptually similar to the image sensor in a digital camera.
The electrons hit a small flat rectangular solid state target, conceptually similar to the image sensor in a digital camera.
The resolution of the target is 512×512, giving 512 points in the time domain and 9-bit linear quantization of the input voltage.
The resolution of the target is 512×512, giving 512 points in the time domain and 9-bit linear quantization of the input voltage.
With a [[7B92]] sweeping the whole X-axis in 5 ns, and the 7912 capturing 512 samples in that sweep, the 7912 performs the function of a 100 GSample/s A/D converter.


With a [[7B92]] sweeping the whole X-axis in 5 ns, and the 7912 capturing 512 samples in that sweep,
==7912 Series Models==
the 7912 performs the function of a 100 GSample/s A/D converter.
* The '''[[R7912]]''', introduced in September 1973 (Ref.1), achieved a bandwidth of 500 MHz with a [[7A19]] vertical amplifier plug-in.
* The '''[[7912AD]]''' (1978) had 500 MHz bandwidth and introduced a standard [[GPIB interface]].
* The '''[[7912HB]]''' (1987) extended bandwidth to 750 MHz (using a [[7A29P]] amplifier).


The primary markets for the 7912 series were nuclear and laser research. 
* The [[LM7912]] is a Tektronix R7912 modified by Lockheed Palo Alto Research Lab for extended bandwidth.
 
==R7912==
The '''R7912''', introduced in September 1973 (Ref.1), 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 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. 
The Tektronix 067-0679-00 Digital Display Controller is an external module that interfaces with the 7912 and an analog X-Y storage display ([[607?]]).
Tek also offered configurations with multiple R7912s on a common controller within the WP2000 series.
 
==7912AD and 7912HB==
From the '''7912AD''' (1978) on, the instrument had a standard [[GPIB interface]].
The 7912AD has 500 MHz bandwidth.  It was succeeded by the 750 MHz 7912HB in 1987 (using a [[7A29P]] amplifier).
 
For the 7912AD and 7912HB, special GPIB-controllable plug-in modules with a 'P' suffix, meaning Programmable,
were available, e.g. [[7A16P]], [[7A29P]] and [[7B90P]].
 
===7912AD Options===
* Option 4: Change to fast digitize mode. This option trades off scan time with resolution by compressing the scan. The target is written on and read from a 256 x 256 point matrix with a maximum of 14 points stored per vertical scan. This option is achieved by setting the correct jumpers on the A16, A20, A22, A26, A46 boards.
* Option 13: Changes the video output to 625 lines/frame with a 50 Hz field rate (PAL). This option is achieved by setting the correct jumpers on the A20 and A28 boards.
 
==Internals==
Three output methods are provided: Video (NTSC or PAL), X-Y-Z low-speed analog, and a [[GPIB interface]]. For video-out Tektronix recommends the [[634|634 monitor]] or a monitor from the 650- and 670-series and a 75 Ω termination. For X-Y-Z analog Tek recommends a 600-series monitor and no specific termination requirement. 
 
With aftermarket modifications to the electronics, 7912AD bandwidths have been extended up to 3 GHz in special cases.
 
==Specifications==
 
The Tektronix 7912AD is 19" wide, 7" tall, 27" deep, and weighs 55 pounds.  It uses 360 watts maximum.
 
==Literature and Software==
# [http://tekretirees.org/Newsletter/nov2012_trn.pdf Hale Farley, ''The introduction of the R7912''] in Tek Retirees Newsletter 11/2012
# [http://w140.com/US3748585.pdf US Patent 3748585: ''Silicon Diode Array Scan Converter Tube and Method of Operation''.  Culter et al, July 1973.]
# [http://pwww.lle.rochester.edu/media/publications/lle_review/documents/v25/25_Review.pdf 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)"''
# [http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/10/434/10434659.pdf Lockheed Palo Alto Research Lab study for LLL (June 1978)] describing the LM7912 Enhanced Performance Transient Digitizer, claiming 3 GHz bandwidth
# [http://w140.com/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]
# [http://www.scottpages.net/MESCthesis.pdf Thesis on "7912ADM" upgrade version]
# [http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/Transient%20Digitizers/RISOM2873.pdf ''Improvement of the Bandwidth of the Transient Digitizers in the LIDAR Thomson Scattering Diagnostic on JET''. Risø National Laboratory, Denmark, June 1990] discussing how removing the delay line and replacing the compensation circuit can boost the 7912AD+7A29 combination to 1.1 GHz bandwidth
# [http://w140.com/kurt/7912_gpib_examples.zip 7912 GPIB examples]
 
==Links==
* [[Carlo Infante]]: A New Way to Look At Transients (R7912).  In [[Media:Tekscope 1973 V5 N6 Nov 1973.pdf  |  TekScope Vol. 5 No. 6, Nov-Dec 1973]]
* [http://www.radiomuseum.org/forum/tektronix_r7912_transient_digitizer.html Tek R7912 @ radiomuseum.org]
 
* [[Dale Aufrecht]]: An Intelligent, Programmable Transient Digitizer (7912AD).  In [[Media:Tekscope 1979 V11 N1.pdf | TekScope Vol. 11 No. 1, 1979]]
* [http://www.radiomuseum.org/r/tektronix_7912ad.html Tek 7912AD @ radiomuseum.org]
 
==See Also==
* [[WP2051]], [[WP2052]]
* [[SCD1000]], [[SCD5000]]
* [[670-6466-00]] 7912 AD plug-in interface extender
* [[067-0854-00]] Calibration Kit
 
==Pictures==
 
===R7912===
<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|WP 2000 front next to [[608]] monitor
Tek wp2000 3.jpg|WP 2000 rear next to [[608]] monitor
Tek wp2000 1.jpg|WP 2000 detail
</gallery>
 
===7912AD===
<gallery>
7912ad tube.gif | 7912AD digitizer tube
TEK Tube7912 Pic5.jpg  | T7912 tube - read part (left), target (center), write part (right). See [[T7912]] article for more photos.
7912ad-block.png | 7912AD block diagram
7912ad.jpg|7912AD front
IMG 20130408 115501.jpg|7912AD TV output on NTSC monitor
Tek7912AD Top.JPG | 7912AD top view, cover removed
Tek7912ad ieee488 top.jpg|7912AD IEEE 488
Tek7912ad ieee488 bot.jpg|7912AD IEEE 488
Tek7912ad mpu top.jpg|7912AD MPU
Tek7912ad mpu bot.jpg|7912AD MPU
Tek7912ad 5156 bot.jpg|7912AD 5156
Tek7912ad 5156 top.jpg|7912AD 5156
Tek7912ad data buffer top.jpg|7912AD data buffer
Tek7912ad data buffer bot.jpg|7912AD data buffer
Tek7912ad translator top.jpg|7912AD translator
Tek7912ad translator bot.jpg|7912AD translator
Tek7912ad graticule gen top.jpg|7912AD graticule generator
Tek7912ad graticule gen bot.jpg|7912AD graticule generator
Tek7912ad x-y ramp gen top.jpg|7912AD X-Y ramp generator
Tek7912ad x-y ramp gen bot.jpg|7912AD X-Y ramp generator
Tek7912ad video proc top.jpg|7912AD video processor
Tek7912ad 4377.jpg|7912AD 4377
Tek7912ad horiz.jpg|7912AD horizontal
Tek7912ad scan amp.jpg|7912AD scan amplifier
Tek 670-6466-00 1.jpg | 670-6466-00 plug-in extender
Tek 7912AD-670-5157-00-power-connector-pcb 1.jpg|7912AD power connector PCB
Tek 7912AD-670-5157-00-power-connector-pcb 2.jpg|7912AD power connector PCB
</gallery>
===7912HB===
<gallery>
Tek 7912hb 1.jpg|7912HB
Tek 7912hb 2.jpg|7912HB
Tek 7912hb 3.jpg|7912HB
Tek 7912hb 4.jpg|7912HB
</gallery>


==Project Staff==
* [[Carlo Infante]], Program manager
* [[Jim Cavoretto]], Project Engineer
* [[Al Allworth]], [[Don Roberts]], and [[Stu McNaughton]], Electrical Engineers
* [[Walt Lowy]], Engineering Technician
* [[Ray Hayes]], [[Ken Hawken]], [[Bob Culter]], [[Hal Cobb]], [[Ed Ritz]], and [[Bo Janko]], CRT Engineering
* [[Loyal Strom]], [[Helene Albright]] and [[Ken Nesvold]], Prototype Support
* [[Doug Giesbers]], [[Larry Pearson]] and [[Phil Lloyd]], Mechanical Engineering
* [[Nick Hughes]] and [[Ray Blohm]], Instrument Manufacturing


[[Category:7000 series digitizer mainframes]]
[[Category:7000 series digitizer mainframes]]
[[Category:Scan converter based instruments]]
[[Category:Scan converter based instruments]]
[[Category:Specifications needed]]
[[Category:GPIB interface]]

Revision as of 05:26, 14 December 2023

Tektronix 7912
500/750 MHz digitizer
Tektronix 7912AD with 7A26 and 7B90P

Produced from 1973 to 1989

Manuals
  • see individual model pages
(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix 7912 is a series of high-speed digitizers that take one 7000-series vertical plug-in and one 7000-series horizontal plug-in. The primary markets for the 7912 series were nuclear and laser research.

All 7912 models use the same internal CRT-based, digitizing scan converter tube (T7912, 154-0698-00) that is not visible from the outside. The signal from the vertical plug-in deflects a writing beam through distributed deflection plates. The electrons hit a small flat rectangular solid state target, conceptually similar to the image sensor in a digital camera. The resolution of the target is 512×512, giving 512 points in the time domain and 9-bit linear quantization of the input voltage. With a 7B92 sweeping the whole X-axis in 5 ns, and the 7912 capturing 512 samples in that sweep, the 7912 performs the function of a 100 GSample/s A/D converter.

7912 Series Models

  • The R7912, introduced in September 1973 (Ref.1), achieved a bandwidth of 500 MHz with a 7A19 vertical amplifier plug-in.
  • The 7912AD (1978) had 500 MHz bandwidth and introduced a standard GPIB interface.
  • The 7912HB (1987) extended bandwidth to 750 MHz (using a 7A29P amplifier).
  • The LM7912 is a Tektronix R7912 modified by Lockheed Palo Alto Research Lab for extended bandwidth.

Project Staff