Tektronix 571 curve tracer for checking / matching / analyzing bipolar transistors and FETs etc. Takes about 30 seconds for the CRT to stabilize (see photos) then is ready to use. Poor photos due to the camera's shutter interacting with the CRT refresh (which seems slower than 60 Hz). It's a light weight, almost portable, unit. Two available. Also have a Tek 370 that passes self test but has many broken switches so is currently unusable.