RE: Portable Oscilloscopes will Require Upgrades to Become Widely Adopted

battlecoder — Mon, 07 Oct 2024 01:53:28 GMT

I've been thinking a lot about this after the poll was up. And I played a bit with my scopes to explore their usefulness and compare them against each other (which I wanted to turn into a post but I couldn't find a way of keeping it concise).

What I found, however, is that more than bandwidth the real struggle seems to be the sampling and triggering. A couple of scopes I own, failed to trigger consistently, resulting in jittering traces and missing bits of signal.

Sometimes this happens because cheap handheld scopes push their ADCs beyond their specs, and do interleaved sampling with very little or no correction, so their "waveform reconstruction" is slow and inaccurate, giving the "jiggly" trace. Since most of them trigger by checking the waveform buffer (and sometimes that implementation is severely flawed) that leads to a slow reaction time, missing events in the signal, flickering or jiggling, etc.

The fact that some of the cheaper scopes exaggerate their specs and struggle to work with anything but the most basic, periodic, low frequency signals, turn them into a frustrating experience. And that's the kind of scope most hobbyist end up buying (I mean, I'm sure a beginner is not buying a Fluke handheld scope, which probably meets specs perfectly, and samples and triggers just fine)

Having said that, not all of the cheap scopes are trash. I don't own any fancy handheld scope, and yet a couple of the ones I have seem to be reasonably well implemented, and have proved to be extremely useful to me, despite being "basic", feature-wise