There are some budget sampling oscilloscopes on the market, but budget is still mid four figures and up. That's before probes, cabling, and other things you'd need. Sampling oscilloscopes are only useful for repeating test patterns sent by SDK tools, not for capturing normal data as it goes by
It's possible to look at Ethernet signals with oscilloscopes in the budget range but you would need appropriate fixtures to tap the line. Even at those speeds, touching a regular oscilloscope probe on to a wire disturbs the circuit so much that it might stop communicating.
https://www.mattkeeter.com/blog/2022-08-11-udp/probes_full.j...
Typo? I didn't think we had sample rates anywhere near that high!
https://www.tek.com/en/documents/application-note/real-time-...
You have to have the 240V model of the scope to run all four channels at full rate (110GHz) though.
The calibration procedure on the scope fiddles with the time alignment to get the different DACs correctly offset so that the combined signal is correct.
The hybrid ceramic input boards in their metal cases are a thing of beauty, fragile (don't ask how I know), but beautiful.
What you can do, if and only if you have an exactly repeating signal triggering at the same point within a cycle, is change the delay between the trigger and sample, and repeat. In other words, sample at different times within the same signal (since it's exactly repeating), to build up samples in time, of that waveform, to whatever time resolution you want.
Of course, you're limited to any noise in the trigger, variation in the signal, etc.
This is how you can record light moving through your garage [1]!
The number he's referring to is in units of samples per second. It's not doing interpolation between samples, to achieve a high samples per second, because that's not possible, which is my point. Interpolation results in an imagined value, but samples are measured values.
It would be correct to say that the values between samples are interpolated, but the subject of interpolation isn't applicable for anything mentioned in this comment chain.
The only time these are interpolating is when they are visualizing, there is no point (hah) in storing interpolated data, you can generate that whenever you want.
