The circuit goes all the way back to that link I provided a couple of posts back
https://www.eevblog.com/forum/testgear/starter-scope/50/ Starting at Reply 52
Basically, there are just two components: a 10k resistor and a 0.1 ufd capacitor. I do 4 experiments in that thread starting at Reply 52
thanks, as soon as i have time i try to run these circuits, let's see if i will understand something
Those experiments were based on the Analog Discovery 2 and were intended to show where the AD2 could do things that an ordinary scope can't.
You can do the Forced Response experiment, we have been talking about this just above.
The Bode' Plot is possible on some versions of the Siglent scope but only if you have a Siglent AWG to link to the scope.
The Phase Shift experiment is based on a differential measurement across the resistor. Even if the Siglent could do an A-B across the resistor, there wouldn't' be a 3rd channel to measure the capacitor voltage. There may be some other way to get this result but it's the result that is worth understanding.
The Impedance experiment is based on a particular adapter for the AD2 and a sweeping AWG linked to the scope.
When I posted those experiments, I was in the mode of 'selling' the AD2. It's no secret that I think highly of the gadget. One contributor elevated me to "Team Coach for AD2" (in jest,of course) because I won't quit talking about it. I just don't talk about it when the topic is troubleshooting random pieces of electronics. It would be inappropriate for vacuum tube radios (I think) but it would work great for Arduino projects at low voltages. Yes, 100x probes are also a possibility, as are 10x (fixed) which I have purchased.
The AD2 was intended for 'learning' electronics and it can do things that would otherwise require an entire bench full of test equipment. But it has its limitations and voltage is one of them. It also doesn't have very high frequency response. It's best used for 'learning' and that's what those 4 experiments were about.