7934
The Tektronix 7934 is a 500 MHz CRT storage scope multi-mode storage mainframe that accepts two 7000-series vertical plug-ins and two 7000-series horizontal plug-ins.
It is the fastest analog storage oscilloscope ever built with 500 MHz of bandwidth, surpassing the 400 MHz 7834.
Amplifiers are normally installed in the two vertical bays to provide vertical beam deflection, and time-bases in the two horizontal bays to provide horizontal beam deflection.
Amplifiers may be installed in horizontal slots for X-Y operation, and time-bases in vertical slots to provide a raster display.
Two-bay modules are typically installed in the middle two bays, which enables them to provide both vertical and horizontal deflection of the beam, while three-bay modules are typically installed in the three left-most bays (two vertical and one horizontal slot) to maintain compatibility with three-bay mainframes.
The 7934 makes extensive use of custom integrated circuits and hybrid circuits. With the exception of the on-screen readout circuit, the signal path is completely differential and all of the internal wiring is 50 Ω coax.
Many orthogonal modes of operation are available on the 7934, which control the vertical mode, horizontal mode, storage mode, and triggering:
The mainframe has the usual analog ch1/ch2/alt/chop/add vertical-mode functions for the two vertical bays, though in the case of the 7934, the two channels are replaced by "left" and "right" to indicate that each mode will slave the vertical deflection to that vertical bay rather than a specific channel. The mainframe provides chop and alt synchronization signals to both vertical bays, which are used by dual-channel plug-ins to switch between the plug-in's channels when the plug-in is set to alt or chop mode.
Both horizontal compartments are triggerable from either vertical compartment, through an internal signal path. Amplifier plug-ins with two channels provide a switch to select which channel will be given to the mainframe for routing to the triggers.
The horizontal modes (A/B/alt/chop) allow the horizontal deflection to be controlled by either the A or B compartment only, or by both, on a time-sharing basis. The mainframe also provides hold-off signals between the two horizontal, which allows a delaying time-base in the A compartment to trigger a delayed time-base in the B compartment. Both the delaying and delayed timebases can be displayed on the screen at once by selecting the chop horizontal mode.
Connectors on the rear of the mainframe provide a sample of either the A or B compartment's output as well as either compartment's internal trigger signal. Only one connector is available for each function, and the compartment is selected by jumpers on a circuit board near the rear of the case.
Dennis Tillman wrote:
The 7934 is an uncommon scope because it came out late in the 7000 lifecycle (1987). For some odd reason it was not listed in the 1988 catalog but it reappeared in the 1989 and 1990 catalogs. In most respects it is a higher bandwidth 7834 which was discontinued after 1985. The 7834 was a 400 MHz scope, but the 7934 is the fastest analog storage scope Tek made at 500 MHz.
Specifications
- Bandwidth: 500 MHz
- readout
- storage modes: normal, bi-stable (standard and "fast"), variable-persistence (standard and "fast")
- independently-switchable reduced-scan mode (to aid high-speed writing)
- timed auto-erase
Prices
Mainframe only − 1990: $15,100 (2019 value: $29,370)
Links
Pictures
Schematics
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Storage Block Diagram
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Timing Diagram Storage Fig. 4-44 B
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Timing Diagram Storage Fig. 4-45 VP
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Timing Diagram Storage Fig. 4-46 FB
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Timing Diagram Storage Fig. 4-47 FVP
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Troubleshooting Chart and Preliminary Setup
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Fig. 5 Power Supply
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Location of Circuit Boards
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Option Information Locator
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Schematic 16 Storage Control and Trace Align A
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Schematic 16 Storage Control and Trace Align B
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Basic Block Diagram
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Cabling A
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Cabling B
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Fig. 2 Display Unit
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Fig. 3 HV and Fan
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Schematic 14 Z Axis and CRT
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Schematic 17 Storage Display
Custom ICs used in the 7934