Tektronix AM502 Differential Amplifier Plug-In

Tektronix Type L Fast Rise Preamp Tube Vintage Oscilloscope Test Inst. Plug in

Tektronix Type 3A3 Plug In, differential dual trace plug-in, untested

UNTESTED Tektronix Type L Plug-In Unit Fast-Rise Calibrated Preamp ~ Made in USA

Tektronix Type 3B1 Plug In, Time Base, untested

tektronix type 53 / 54D high gain preamp plug-in untested

Tektronix 7A16A Amplifier Plug-in

Tektronix 7A22 Differential Amplifier Plug-In