7A26

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
Input impedance	1 MΩ // 22 pF
Deflection factor	5 mV/Div – 5 V/Div in 1–2–5 sequence
Features	Bandwidth limiting switch (20 MHz)

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.

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 resoldering.

Links

• Tek 7A26 @ amplifier.cd
• Tek 7A26 @ barrytech.com
• Tom Rousseau's Golden 100,000th 7A26
• Zenwizard Studios - Tektronix 7a26 Restoration and Alignment

Pictures

• 

  Front panel

• 

  left side

• 

  right side

• 

  Cartoon in schematic: The 7A26 Sharp Shooter

Custom ICs used in the 7A26