7912

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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.

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.

The primary markets for the 7912 series were nuclear and laser research.

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 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.

7912AD and 7912HB

From the 7912AD (1978) on, the instrument had a standard GPIB interface and could drive X-Y monitors directly. In contrast to the earlier R7912 the readout characters in video mode are now created digitally and directly injected into the video signal. 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 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 consumes 360 watts maximum.

Literature and Software

  1. Hale Farley, The introduction of the R7912 in Tek Retirees Newsletter 11/2012
  2. US Patent 3748585: Silicon Diode Array Scan Converter Tube and Method of Operation. Culter et al, July 1973.
  3. 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)"
  4. Lockheed Palo Alto Research Lab study for LLL (June 1978) describing the LM7912 Enhanced Performance Transient Digitizer, claiming 3 GHz bandwidth
  5. William B. Boyer, Data Acquisition and Processing on Electron Beam Fusion Accelerators. IEEE Transactions on Nuclear Science Vol.NS-25, No. 1, February 1978
  6. Thesis on "7912ADM" upgrade version
  7. 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
  8. 7912 GPIB examples

Links

See Also

Pictures

R7912

7912AD

7912HB

Custom ICs used in the R7912

Page Class Manufacturer Model Part nos Description Designers Used in
155-0011-00 Monolithic integrated circuit Tektronix M012 155-0011-00 clock and chop blanking Les Larson 485 7313 7403N R7403N 7503 7504 7514 7603 AN/USM-281C 7613 7623 7623A 7633 7704 R7704 7704A 7834 7844 7854 7904 7904A R7903 R7912 7912AD 7912HB 7934 7104 R7103 AN/USM-281C
155-0012-00 Monolithic integrated circuit Tektronix M015 155-0012-00 Z Axis Logic Les Larson 485 7504 7514 7704 R7704 7704A 7834 7844 7854 7904 R7903 7904A R7912 7934 7912AD 7912HB 7104 R7103
155-0022-00 Monolithic integrated circuit Tektronix M036 155-0022-00 155-0022-01 analog multiplexer Gene Andrews 147 148 149 335 468 1430 1441 1461 1900 1910 2220 2221 2230 5223 5403 5440 5441 5443 5444 5A38 7313 7403 7503 7504 7514 7603 AN/USM-281C 7613 7623 7623A 7633 7704 R7704 7704A 7834 7844 7854 R7912 7912AD 7912HB 7904 R7903 7904A 7934 7A12 7A18 7A18A 7B52 7B53N 7D10 7D11 7D12 NT-7000 P7001
155-0048-01 Monolithic integrated circuit Tektronix M052F 155-0048-00 155-0048-01 155-0055-00 155-0055-01 trigger sweep Dave Allen 211 212 213 214 432 433 5B12N 5B13N 5L4N 603 604 605 606 607 624 SC501 R7912
155-0059-00 Monolithic integrated circuit Tektronix M077A 155-0059-00 HF amplifier Thor Hallen 7834 7844 7854 7904 R7903 R7912 7912AD
155-0060-00 Monolithic integrated circuit Tektronix M071E 155-0060-00 155-0060-01 channel selector amplifier Hans Springer R7903 7904 R7912
155-0065-00 Hybrid integrated circuit Tektronix H074 155-0065-00 155-0064-01 155-0125-00 deflection amplifier 7844 7904 R7912 R7903
155-0067-02 Monolithic integrated circuit Tektronix M091B 155-0067-00 155-0067-02 155-0067-03 SMPS controller Joe Burger Gene Andrews 7704A 7834 7844 7854 7904 R7903 7904 7904A 7934 R7912 7912AD 7912HB 7934 7104 R7103 308 434 485 690 P7001
155-0078-00 Monolithic integrated circuit Tektronix M084 155-0078-xx 155-0273-00 155-0274-00 broadband vertical amplifier John Addis 464 465 466 468 475 475A 475M 485 7834 7844 7854 7904 R7903 R7912 7912AD 7912HB 7104 7A16A 7A16P 7A24 7A26 7A42 067-0587-01 067-0680-00 AM503 PG502 PG508 DC510 DC5010 FG5010
155-0095-00 Hybrid integrated circuit Tektronix 155-0095-00 155-0095-00 155-0095-01 155-0095-03 HF differential amplifier 7834 7844 7904 R7903 R7912 7912AD

Custom ICs used in the 7000 series readout system

Page Class Manufacturer Model Part nos Description Designers Used in
155-0014-01 Monolithic integrated circuit Tektronix M019D 155-0014-00 155-0014-01 A/D converter Barrie Gilbert 7000 series readout system 7854 7J20 7L5 P7001
155-0015-01 Monolithic integrated circuit Tektronix M020F 155-0015-00 155-0015-01 analog data switch Barrie Gilbert 7000 series readout system 7854
155-0017-00 Monolithic integrated circuit Tektronix M025 155-0017-00 5 MHz decade counter Barrie Gilbert 7000 series readout system 7854
155-0018-00 Monolithic integrated circuit Tektronix M026 155-0018-00 zeros logic control Les Larson 7000 series readout system
155-0019-00 Monolithic integrated circuit Tektronix M027 155-0019-00 decimal point and spacing control Les Larson 7000 series readout system
155-0020-00 Monolithic integrated circuit Tektronix M028 155-0020-00 output assembler Les Larson 7000 series readout system
155-0021-00 Monolithic integrated circuit Tektronix M029C 155-0021-00 155-0021-01 timing generator Les Larson 7000 series readout system 7854
155-0023-00 Monolithic integrated circuit Tektronix 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 Monolithic integrated circuit Tektronix M161 155-0024-00 character generator (↓ < I / + - + C Δ >) Barrie Gilbert 7000 series readout system
155-0025-00 Monolithic integrated circuit Tektronix 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 Monolithic integrated circuit Tektronix 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 Monolithic integrated circuit Tektronix M164 155-0027-00 character generator (U N L Z Y P F J Q D) Barrie Gilbert 7000 series readout system

CRTs used in the R7912

Page Description Designers Used in
T7912 scan converter tube R7912 7912AD 7912HB


Custom ICs used in the 7912AD

Page Class Manufacturer Model Part nos Description Designers Used in
155-0011-00 Monolithic integrated circuit Tektronix M012 155-0011-00 clock and chop blanking Les Larson 485 7313 7403N R7403N 7503 7504 7514 7603 AN/USM-281C 7613 7623 7623A 7633 7704 R7704 7704A 7834 7844 7854 7904 7904A R7903 R7912 7912AD 7912HB 7934 7104 R7103 AN/USM-281C
155-0012-00 Monolithic integrated circuit Tektronix M015 155-0012-00 Z Axis Logic Les Larson 485 7504 7514 7704 R7704 7704A 7834 7844 7854 7904 R7903 7904A R7912 7934 7912AD 7912HB 7104 R7103
155-0022-00 Monolithic integrated circuit Tektronix M036 155-0022-00 155-0022-01 analog multiplexer Gene Andrews 147 148 149 335 468 1430 1441 1461 1900 1910 2220 2221 2230 5223 5403 5440 5441 5443 5444 5A38 7313 7403 7503 7504 7514 7603 AN/USM-281C 7613 7623 7623A 7633 7704 R7704 7704A 7834 7844 7854 R7912 7912AD 7912HB 7904 R7903 7904A 7934 7A12 7A18 7A18A 7B52 7B53N 7D10 7D11 7D12 NT-7000 P7001
155-0059-00 Monolithic integrated circuit Tektronix M077A 155-0059-00 HF amplifier Thor Hallen 7834 7844 7854 7904 R7903 R7912 7912AD
155-0064-00 Hybrid integrated circuit Tektronix H074A 155-0064-00 vertical output amplifier 7834 7854 7904 R7903 7912AD 485 PG502
155-0067-02 Monolithic integrated circuit Tektronix M091B 155-0067-00 155-0067-02 155-0067-03 SMPS controller Joe Burger Gene Andrews 7704A 7834 7844 7854 7904 R7903 7904 7904A 7934 R7912 7912AD 7912HB 7934 7104 R7103 308 434 485 690 P7001
155-0078-00 Monolithic integrated circuit Tektronix M084 155-0078-xx 155-0273-00 155-0274-00 broadband vertical amplifier John Addis 464 465 466 468 475 475A 475M 485 7834 7844 7854 7904 R7903 R7912 7912AD 7912HB 7104 7A16A 7A16P 7A24 7A26 7A42 067-0587-01 067-0680-00 AM503 PG502 PG508 DC510 DC5010 FG5010
155-0095-00 Hybrid integrated circuit Tektronix 155-0095-00 155-0095-00 155-0095-01 155-0095-03 HF differential amplifier 7834 7844 7904 R7903 R7912 7912AD

CRTs used in the 7912AD

Page Description Designers Used in
T7912 scan converter tube R7912 7912AD 7912HB


Custom ICs used in the 7912HB

Page Class Manufacturer Model Part nos Description Designers Used in
155-0011-00 Monolithic integrated circuit Tektronix M012 155-0011-00 clock and chop blanking Les Larson 485 7313 7403N R7403N 7503 7504 7514 7603 AN/USM-281C 7613 7623 7623A 7633 7704 R7704 7704A 7834 7844 7854 7904 7904A R7903 R7912 7912AD 7912HB 7934 7104 R7103 AN/USM-281C
155-0012-00 Monolithic integrated circuit Tektronix M015 155-0012-00 Z Axis Logic Les Larson 485 7504 7514 7704 R7704 7704A 7834 7844 7854 7904 R7903 7904A R7912 7934 7912AD 7912HB 7104 R7103
155-0022-00 Monolithic integrated circuit Tektronix M036 155-0022-00 155-0022-01 analog multiplexer Gene Andrews 147 148 149 335 468 1430 1441 1461 1900 1910 2220 2221 2230 5223 5403 5440 5441 5443 5444 5A38 7313 7403 7503 7504 7514 7603 AN/USM-281C 7613 7623 7623A 7633 7704 R7704 7704A 7834 7844 7854 R7912 7912AD 7912HB 7904 R7903 7904A 7934 7A12 7A18 7A18A 7B52 7B53N 7D10 7D11 7D12 NT-7000 P7001
155-0067-02 Monolithic integrated circuit Tektronix M091B 155-0067-00 155-0067-02 155-0067-03 SMPS controller Joe Burger Gene Andrews 7704A 7834 7844 7854 7904 R7903 7904 7904A 7934 R7912 7912AD 7912HB 7934 7104 R7103 308 434 485 690 P7001
155-0078-00 Monolithic integrated circuit Tektronix M084 155-0078-xx 155-0273-00 155-0274-00 broadband vertical amplifier John Addis 464 465 466 468 475 475A 475M 485 7834 7844 7854 7904 R7903 R7912 7912AD 7912HB 7104 7A16A 7A16P 7A24 7A26 7A42 067-0587-01 067-0680-00 AM503 PG502 PG508 DC510 DC5010 FG5010
155-0175-00 Monolithic integrated circuit Tektronix H476 155-0175-00 broadband amplifier John Addis Wink Gross Carl Battjes 7904A 7912HB 7934 7104 R7103 7A29 7A29P 7F10 067-0587-02 067-0587-10 11A71 SCD1000 EG&G N-AM-173A
155-0178-00 Hybrid integrated circuit Tektronix H488 155-0178-00 horizontal output amplifier Dave Morgan 7904A 7912HB 7934 7104

CRTs used in the 7912HB

Page Description Designers Used in
T7912 scan converter tube R7912 7912AD 7912HB