The Tektronix 7704A oscilloscope is the most modular analogue oscilloscope I know: not only does it have space for four amplifier and trigger plugins, but even the 'display unit' holding the CRT can be swapped for another one.
After several years of owning a spare 'display unit' I finally have a project where this strange feature may turn out to be actually useful. But first these machines need some maintenance and repair.









