7A26: Difference between revisions

Revision as of 09:19, 12 August 2020

Template:Plugin Sidebar 2 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-ins, 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 the conductive traces on 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

Pictures

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

@@ Line 12: / Line 12: @@
 * [http://w140.com/smb/7a26_sm.pdf Tektronix 7A26 Manual (OCR, PDF)]
 * [[Media:Tek 7A26 german user sm.pdf|Tektronix 7A26 Description in German (OCR, PDF)]]
+* [[Media:040-0785-01.pdf|7A26 Vertical amplifier replacement (PDF)]]
+* [[Media:070-1484-00.pdf|7A26 Instruction Manual, part no 070-1484-00 (PDF)]]
+* [[Media:070-1484-01.pdf|7A26 Instruction Manual, part no 070-1484-01 (OCR, PDF)]]
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 The '''Tektronix 7A26''' is a 200 MHz dual-trace vertical plug-in for [[7000-series scopes]].