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The Tektronix 132 is an external enclosure, power supply, and amplifier for a letter-series or 1-series plug-in. It was introduced in 1961.

The 132 supplies power to the plug-in and the signal output of the plug-in (i.e., at pins 1 and 3 of the plug-in's rear connector) is amplified by the three-stage DC-to-16 MHz all-tube differential amplifier in the 132. The resulting vertical signal is available on the front panel of the 132 either using UHF connectors (early 132 versions) or BNC connectors (late 132 versions).

The 132's power supply is similar to Tektronix oscilloscopes of the late 1950s and early 1960s. The rectifier diodes are solid state, but the regulators are tube. An OG3 tube is used to generate a -150 V reference voltage that is used for all of the other regulated voltages. The +225 V and +350 V supplies are floating supplies stacked on top of the +189 V unregulated DC that feeds the +100 V supply. The 132 has a fan that is always on when the power is on, and a 137 °F (58 °C) thermal cutoff for the rest of the circuitry.

The differential front panel output of the 132 has an output impedance of about 5 kΩ per side. The gain and bandwidth of the entire system (plug-in + 132 + load) depend on the load impedance. For exact gain, the 132 needs to be terminated with an exact impedance. A load impedance of 93 Ω maximizes bandwidth and further reductions of load impedance only reduce the available output swing. A load impedance of 50 kΩ maximizes gain and further increases in load impedance have little effect on system performance.