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Tektronix 7A26
200 MHz dual-channel amplifier
7A26 front panel

Compatible with 7000-series scopes

Produced from 1974 to 1991

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 // 22 pF
Features Bandwidth limiting switch (20 MHz)


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.

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.



Custom ICs used in the 7A26

Page Model Part nos Description Designers Used in
155-0078-00 M084 155-0078-xx 155-0273-00 155-0274-00 broadband amplifier John Addis 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