127
The Tektronix Type 127 is a power supply and preamplifier for two letter-series or 1-series plug-ins. The Type 127 was introduced in 1958. It is a rack-mount unit with a power supply that resembles the power supply of an early 500-series oscilloscope: a 50/60Hz transformer, selenium rectifiers, a single voltage reference tube controlling all output voltages, and 6080 pass tubes for the regulated outputs. The 127 contains a fully differential DC-coupled 15MHz amplifier for each channel with cathode follower outputs on the front and rear panels.