127

The Tektronix Type 127 is a power supply, calibrator, and unity-gain 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 targets applications where one wants to use Tektronix plug-ins as front-end amplifiers for other instrumentation. Since letter-series and 1-series plug-ins have relatively high output impedance, their outputs (i.e., differentially between pins 1 and 3 of the plug-in-to-scope interconnecting plug) are not suitable for directly driving long cables. The 127 provides 20MHz unity gain amplifiers that can drive long cables and other low impedance loads. Each of the two amplifiers in the 127 is fully differential and outputs are on the front and rear panels. The 127 has unity gain if the output is taken differentially and the load on each output is 170 ohms.

The 127 is a 5U (8.75"/22.2cm) rackmount unit and weighs 37 pounds (16.9kg). Maximum power consumption is 450W.

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  front view

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  open, selenium rectifier

• Tektronix 127 Manual (PDF)
• Tektronix 127 Factory Calibration Procedure (PDF)
• Tektronix 127 in 1968 Catalog (PDF)