7B70
The Tektronix 7B70 is a 200 MHz time-base plug-in for 7000-series scopes. It has no delay function.
For delayed-sweep applications, the 7B70 is operated in conjunction with the model 7B71 delaying timebase. The 7B70/7B71 were primarily intended for the 7704 mainframe.
The task of designing the 7B70 was inherited and completed by Murlan Kaufman.
The 7B71/7B70 were superseded by the 7B85/7B80 pair (400 MHz) in 1976.
Key Specifications
| Sweep | 5 s/Div to 20 ns/Div in 1−2−5 sequence, ×10 magnifier down to 2 ns/Div, variable down to 12.5 s/Div |
|---|---|
| Excluded portions of sweep | None in 7700-series, first 50 ns with magnifier |
| Trigger sensitivity | 0.3 Div (int) or 75 mV (ext) up to 20 MHz, 1.5 Div or 375 mV from 20 MHz to 200 MHz |
| Trigger coupling | DC, AC (>30 Hz), AC HF REJ (30 Hz to 50 kHz), AC LF REJ (>30 kHz) |
| Trigger input | 1 MΩ // 20 pF, max. 500 V DC+peak AC |
| Jitter | less than 1 ns at 150 MHz |
| Trigger Modes | Peak-Peak Auto, Auto, Norm, Single Sweep |
| External horizontal amplifier | 25 mV/Div or 250 mV/Div ranges, variable |
X-Y operation
The 7B70 has a dedicated switch to put it in "amplifier mode" for X-Y operation. In this mode, the Trigger Source switch controls the signal source – internal from a vertical plug-in via the trigger path, or external — and the Trigger Coupling switch controls AC vs. DC coupling.
In amplifier mode, gain can be varied using an uncalibrated potentiometer.
Links
Documents Referencing 7B70
| Document | Class | Title | Authors | Year | Links |
|---|---|---|---|---|---|
| Tekscope 1969 V1 N5 Oct 1969.pdf | Article | Introducing the New Generation | 1969 | 7000-series scopes • 7504 • 7704 • 7A11 • 7A12 • 7A13 • 7A14 • 7A16 • 7A22 • 7S11 • 7M11 • 7B50 • 7B51 • 7B70 • 7B71 • 7T11 • R5030 • 7000 series readout system • Miniature relays • Cam switches • Industrial Design • T7500 • T7700 • P6052 • P6053 • C-50 • C-51 • 204-2 | |
| Tekscope 1969 V1 N6 Dec 1969.pdf | Article | A New Logic for Oscilloscope Displays | 1969 | 7000-series scopes • 7A11 • 7A12 • 7A13 • 7A14 • 7A16 • 7A22 • 7B50 • 7B51 • 7B70 • 7B71 • 7S11 • 7T11 • 7504 • 7704 | |
| Tekscope 1974 V6 N4.pdf | Article | Troubleshooting the 7B70 and 7B71 Time Bases | Jim Lawe | 1974 | 7B70 • 7B71 |
| Tekscope 1974 V6 N5.pdf | Article | Understanding oscilloscope trigger controls | 1974 | 475 • 7B70 |
Internals
The 7B70 contains five 148-0034-00 miniature relays and one 148-0035-00. It also contains one 152-0154-00 and two 152-0125-00 tunnel diodes.
Pictures
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7B70, front panel
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1973 LHS
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1973 RHS
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1969 LHS
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1969 RHS
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Components
Some Parts Used in the 7B70
| Part | Part Number(s) | Class | Description | Used in |
|---|---|---|---|---|
| 148-0034-00 | 148-0034-00 | Discrete component | miniature DPDT relay | 7A11 • 7A13 • 7A14 • 7B70 • 7B71 • 7503 • 7904 • 7904A |
| 148-0035-00 | 148-0035-00 | Discrete component | miniature SPDT relay | 7A13 • 7A14 • 7B70 • 7B71 |
| 1N3717 | 152-0381-00 • 152-0125-00 | Discrete component | 4.7 mA, 25 pF tunnel diode | 1L40 • 1S1 • 1S2 • 11B1 • 11B2 • 11B2A • 147A • 1470 • 148 • 21A • 22A • 3B4 • 3B5 • 408 • 432 • 434 • 453 • 453A • 454 • 466 • 491 • 5T3 • 544 • RM544 • 546 • RM546 • 547 • RM547 • 556 • RM556 • 7B70 • 7B71 • 7D11 |
| SMTD995 | 152-0140-01 | Discrete component | 10 mA, 8 pF tunnel diode | 1S1 • 1S2 • 1502 • 21A • 22A • 3T5 • 3T6 • 475 • 475A • 475M • 544 • R544 • 546 • RM546 • 547 • RM547 • 556 • R556 • 581A • 585A • RM585 • 7B52 • 7B53N • 7B70 • 7B71 • 7D10 • 7D11 • 7T11 • 7T11A • R7912 • S-51 • S-52 • TU-5 • 067-0572-00 • 067-0572-01 • 067-0681-00 |
| STD704 | 152-0125-00 | Discrete component | 4.7 mA tunnel diode | 1L40 • 1S1 • 11B1 • 11B2 • 11B2A • 147 • R147 • 147A • R147A • 1470 • 148 • R148 • 148-M • 149 • R149 • 149A • R149A • 21A • 22A • 3B4 • 3B5 • 408 • 432 • 434 • 453 • 453A • 454 • 464 • 465 • 466 • 491 • 5T3 • 544 • RM544 • 546 • RM546 • 547 • RM547 • 556 • RM556 • 7B70 • 7B71 • 7D11 |
| TD253 | 152-0154-00 | Discrete component | 10 mA, 9 pF germanium tunnel diode | 547 • 7B70 |