Tektronix 7854 Waveform Keyboard Rebuild

From the Tek Wiki:

The Tektronix 7854 Waveform Processing Oscilloscope, introduced in 1980, is a 400 MHz combined analog / digital mainframe in the 7000 series that takes two vertical and two horizontal 7000-series plug-ins. In addition to a conventional analog (real time) scope, it contains an equivalent-time sampling 10-bit digitizer and a programmable waveform processor with GPIB interface. The waveform processor can be programmed using a detachable calculator-style keyboard, using postfix operators (“reverse Polish notation” like HP calculators) that operate on entire waveforms, not just individual numbers.

Tek 7854 Mainframe #2 after cleaning

Tek 7854 Mainframe after cleaning

It is to the repair of the detachable keyboard that this post is devoted.  I purchased a keyboard for a reasonable price only to find that some keys were intermittent, and some did not work at all.

Opening up the keyboard showed … Read More »