R7912
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
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 |
| Boyer data acq ebeam fus acc.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