A former coworker friend sent me a Tektronix 3-slot mainframe and several plug-in modules (Fig. 1). The TM500-series mainframes are 1970s vintage, but like a lot of old test equipment, can still work ...

A lifetime of amassing random pieces of test equipment has left me with a gap in my armoury, namely that I don’t possess a low frequency function generator. This could easily be addressed, but for two ...