Tektronix TM503B in Webster, MA, USA

The Tektronix power module mainframe will provide the framework for the TEGAM or the Tektronix modular instrument architecture.
They can be configured with over 50 types of plug in modules ranging from function generators to switching matrixes to provide a compact solution for applications ranging from portable test stations to automated production test sets.
The 500 series plug ins are specifically for TM500 series mainframes and 5000 series plug ins are design to be used with the TM5000 series mainframes.
This is because the TM5000 series mainframes are constructed with additional hardware for GPIB bus configuration.