A
Tektronix model 475A portable analogue oscilloscope, typical of the late
1970s. This dual-trace, dual-sweep instrument had a horizontal bandwidth of 250
MHz, a maximum vertical sensitivity of 5
mV per division, and maximum (unmagnified) horizontal sweep speed of 10
ns per division. The vertical controls are on the left with Channel 1 above and Channel 2 below. The horizontal sweep controls are on the right with the Main Trigger above and the Delayed Trigger below. The
CRT controls are below the screen. The metal loop to the lower right of the screen provided a calibration signal for voltage and current
probes.