7A26
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The Tektronix 7A26 is a 200 MHz dual-trace vertical plug-in for 7000-series scopes. Designed by Tom Rousseau, it was the most successful 7000 series plug-in, with over 120,000 units produced. The military designation is AM-6785/U.
The 75 MHz 7A18 and 400 MHz 7A24 share the same front panel layout and operation.
Key Specifications
| Bandwidth | 200 MHz |
|---|---|
| Deflection | 5 mV/Div – 5 V/Div in 1−2−5 sequence |
| Input impedance | 1 MΩ in parallel with 20pF±0.5pF SN B208879-below and 22pF±0.5pF SN B208880-up |
| Features | Bandwidth limiting switch (20 MHz) |
Links
- See 7A12 for the history of the 7A18, 7A16A, 7A24, and 7A26.
- Tom Rousseau's Golden 100,000th 7A26
- Tek 7A26 @ amplifier.cd
- Tektronix 7A26 Restoration and Alignment by Zenwizard Studios @ YouTube
Patents that may apply to 7A26
| Page | Title | Inventors | Filing date | Grant date | Links |
|---|---|---|---|---|---|
| Patent US 3562464A | Cam actuated switch having movable and fixed contacts on circuit board | Howard Vollum • Willem H Verhoef • Tony Sprando | 1968-10-07 | 1971-02-09 | Cam switches • 1501 • 214 • 2101 • 2701 • 2703 • 26G3 • 432 • 434 • 465 • 475 • 5A15N • 5A18N • 5A20N • 5A21N • 5A22N • 5A26N • 5A38 • 5A45 • 5A48 • 5B10N • 5B12N • 5B31 • 5B40 • 5B42 • 5B44 • 7A15 • 7A16A • 7A18 • 7A18A • 7A19 • 7A22 • 7A24 • 7A26 • 7B10 • 7B15 • 7B50 • 7B51 • 7B52 • 7B53A • 7B50A • 7B70 • 7B71 • 7B80 • 7B85 • 7B87 • 7B92 • 7B92A • 7D01 • 7D12 • 7D15 • 7J20 • 7S12 • 7T11 • 7T11A • AF501 • AM502 • AM503 • DC502 • DC503 • DC504 • DC505 • DM501 • DM502 • FG501 • FG501A • FG502 • FG503 • FG504 • FG507 • PG501 • PG502 • PG503 • PG505 • PG506 • PG506A • PG508 • TG501 • SC502 • SC503 • SC504 |
| Patent US 3719788A | Switch having ganged contacts mounted on opposite sides of circuit board | Ken Holland • Tony Sprando | 1971-02-04 | 1973-03-06 | 465 • 475 • 5A38 • 5A45 • 7A15 • 7A16A • 7A18 • 7A18A • 7A19 • 7A24 • 7A26 • 7D15 • PG506 |
| Patent US 3753170A | Step attenuator apparatus having attenuator stages selectively connected in cascade by cam actuated switches | Ken Holland | 1971-02-10 | 1973-08-14 | 465 • 475 • 5A38 • 5A45 • 7A15 • 7A16A • 7A18 • 7A18A • 7A19 • 7A24 • 7A26 |
| Patent US 3900711A | Electrical contactor assembly for high frequency applications | Ken Holland | 1974-02-04 | 1975-08-19 | 465 • 475 • 5A38 • 5A45 • 7A15 • 7A16A • 7A18 • 7A18A • 7A19 • 7A24 • 7A26 • 7D15 • AM503 |
Prices
| Year | Catalog price | In 2026 dollars |
|---|---|---|
| 1974 | $1,050 | ~$6,900 |
| 1976 | $1,150 | ~$6,600 |
| 1980 | $1,525 | ~$6,000 |
| 1984 | $2,025 | ~$6,300 |
| 1991 | $3,450 | ~$8,200 |
Internals
Controls layout and internal construction is very similar to the 75 MHz 7A18. Whereas the 7A18 is a discrete design, the 7A26 uses Tek-made differential amplifier ICs 155-0078-xx.
The 7A26 does not use the ±50 V supplies provided by the mainframe.
Pictures
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Front panel
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Front panel
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left side
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right side
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Cartoon in schematic: The 7A26 Sharp Shooter
Components
Some Parts Used in the 7A26
| Part | Part Number(s) | Class | Description | Used in |
|---|---|---|---|---|
| 155-0078-00 | 155-0078-xx • 155-0273-00 • 155-0274-00 | Monolithic integrated circuit | broadband amplifier | 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 |
| 2N5911 | 151-1032-00 | Discrete component | dual N-channel JFET (selected) | 015-1057-00 • 318 • 318A • 335 • 336 • 338 • 390AD • 432 • 434 • 442 • 454A • 464 • 465 • 466 • 468 • 485 • 4851 • 4852 • 5A45 • 5A48 • 608 • 7A15A • 7A16 • 7A16A • 7A18 • 7A18A • 7A26 • AM503 • OF151 • OF152 • OF235 • SG50105 • TSG6 • TSG16 • TSG26 • T832A • T935A |
| 307-1012-00 | 307-1012-00 | Discrete component | thick-film 5x attenuator | 7A26 |