Benchtop Oscilloscopes

Bench oscilloscopes are where used buying makes the most sense in general electronics: analogue front ends age extremely well, and the specification that dates an instrument is usually record length rather than bandwidth.

Reading the specification honestly

Bandwidth should be roughly five times the highest frequency component you care about — and for digital signals that is edge rate, not clock rate. A 10 MHz clock with 2 ns edges needs several hundred megahertz to display honestly.

Sample rate is often shared between channel pairs. Record length determines how long you can capture at full rate, and this is where older instruments disappoint: a 2.5 kpt record covers about a microsecond.

Options, licences and probes

Serial decode, advanced triggering and analysis packages are licence keys tied to the serial number, and they do not always transfer on resale. We report the option list as the instrument itself reports it.

Probes can be a third of a package's value. A 1 GHz scope supplied with 200 MHz probes is a 200 MHz scope in practice.

Common questions