3A9
The Tektronix 3A9 is a differential amplifier plug-in introduced in 1969 for 560-series scopes. It shares similarities with the 7A22 from the 7000 series and 26A2 (2600 series).
The 3A9 features a variable high-frequency cut-off from 100 Hz to 1 MHz and a variable low-frequency cut-off from DC to 10 kHz. When DC coupled, the 3A9 provides a variable offset voltage. The common mode rejection is 100,000:1.
The 3A9 provides differential high-impedance voltage inputs and an AC current probe input for use with, for example, the P6021 or P6019.
