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Tektronix 7A13 Differential Comparator 7000 Oscilloscope Plug-In Module (nice)

Tektronix Oscilloscope Plugin Module SI-5010 Programmable Scanner

Tektronix Type 3B3 Plug-in - Time Base for Oscilloscope 564 w/ Manual

Tektronix 7A24 Dual Trace Amplifier 7854 Oscilloscope Plug-In Module (nice)

Tektronix Plug-in Model Pg 501 PULSE GENERATOR