Tektronix TM503 Three-Slot Power Supply Chassis

The Tektronix TM503 Three-Slot Power Supply Chassis is a bench-top modular mainframe that provides regulated DC power and mechanical housing for up to three Tektronix TM500 Series plug-in instruments. Designed to power a wide range of TM500 modules—including oscillators, counters, digital multimeters, pulse generators, amplifiers, calibration modules, and DC power supplies—the TM503 supports instrument expansion for maintenance technicians, calibration engineers, and system integrators in electronics testing, calibration laboratories, manufacturing test stations, product development, educational labs, industrial maintenance, and field service. Key specifications include three plug-in bays, selectable input voltage (100/120/220/240 VAC, 50–60 Hz), maximum power up to 120 W depending on installed modules, and internal forced-air cooling with thermal protection, plus a thermal cutout with automatic reset and line fuse protection. Compatibility is limited to Tektronix TM500 Series plug-in instruments, with common replacement options including the TM501 single-slot, TM504 four-slot, and TM506 six-slot chassis.