7A26: Difference between revisions

Latest revision as of 16:04, 11 October 2024

Tektronix 7A26
200 MHz dual-channel amplifier 7A26 front panel Compatible with 7000-series scopes Produced from 1974 to 1991 Manuals 7A26 Instruction Manual -00 7A26 Instruction Manual -01 Rev. Oct 1982 (OCR) Tek7A26 Anleitung (Operators Manual, German) (OCR) 7A26 Vertical amplifier replacement (OCR) (All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

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 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

Tom Rousseau's Golden 100,000^th 7A26
Tek 7A26 @ amplifier.cd
Tektronix 7A26 Restoration and Alignment by Zenwizard Studios @ YouTube

Documents Referencing 7A26

(no results)

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 • 2101 • 2701 • 2703 • 432 • 434 • 465 • 475 • 5A15N • 5A18N • 5A20N • 5A21N • 5A38 • 5A45 • 5B10N • 5B12N • 7A15 • 7A16A • 7A18 • 7A19 • 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 • 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 • 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 • 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 • 7A19 • 7A24 • 7A26 • 7D15 • AM503

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

Front panel
Front panel
left side
right side
Cartoon in schematic: The 7A26 Sharp Shooter

Components

Some Parts Used in the 7A26

Part	Part Number(s)	Class	Description	Used in
151-1032-00	151-1032-00	Discrete component	dual n-channel JFET (selected)	7A15A • 7A26
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
307-1012-00	307-1012-00	Discrete component	thick-film 5x attenuator	7A26

@@ Line 23: / Line 23: @@
 {{Spec | Bandwidth |200 MHz}}
 {{Spec | Deflection | 5 mV/Div – 5 V/Div in 1−2−5 sequence }}
-{{Spec | Input impedance | 1 MΩ // 22 pF }}
+{{Spec | Input impedance | 1 MΩ in parallel with 20pF±0.5pF SN B208879-below and 22pF±0.5pF SN B208880-up }}
 {{Spec | Features | Bandwidth limiting switch (20 MHz) }}
 {{EndSpecs}}
+==Links==
+* [https://vintagetek.org/100000-7a26-plug-in/ Tom Rousseau's Golden 100,000<sup>th</sup> 7A26]
+* [http://www.amplifier.cd/Test_Equipment/Tektronix/Tektronix_7000_series_amplifier/amplifier_7A26.htm Tek 7A26] @ amplifier.cd
+* [https://www.youtube.com/watch?v=7scgCL_Rl6E Tektronix 7A26 Restoration and Alignment] by Zenwizard Studios @ YouTube
+{{Documents|Link=7A26}}
+{{PatentLinks|7A26}}
 ==Internals==
@@ Line 33: / Line 41: @@
 The 7A26 does not use the ±50 V supplies provided by the mainframe.
-==Repair issues==
-The pins of the attenuator modules are connected to conductive traces on the ceramic substrate inside by low-temperature soldering, which can go bad.
-Re-seating the module can temporarily restore the internal contact but will usually not fix the problem permanently.
-Repair is possible by opening the click-locked lid and carefully re-soldering (see [[307-1012-00]]).
-==Links==
-* [https://vintagetek.org/100000-7a26-plug-in/ Tom Rousseau's Golden 100,000<sup>th</sup> 7A26]
-* [http://www.amplifier.cd/Test_Equipment/Tektronix/Tektronix_7000_series_amplifier/amplifier_7A26.htm Tek 7A26] @ amplifier.cd
-* [http://www.barrytech.com/tektronix/tek7000/tek7a26.html Tek 7A26] @ barrytech.com
-* [https://www.youtube.com/watch?v=7scgCL_Rl6E Tektronix 7A26 Restoration and Alignment] by Zenwizard Studios @ YouTube
 ==Pictures==