How to get the characteristics of the signal passing through the wire, without direct contact (induction, capacitance, etc.)?

Question

Electronics

There is a wire through which the signal passes, I need to get a signal characteristic without a direct connection. Is there a way, roughly speaking, to bring the sensor up and count the electromagnetic field that is created around the wire or something else, given that the signal is low voltage and current strength?

Answer 1

There is a way.

Answer 2

in principle it is possible. It is desirable to know what kind of cable and it is important to understand at what frequencies the signal, the higher the frequency - the higher the skin effect and the signal as it rushes outward from the center, the more screens, braids, etc.
You can even do it with a simple usb oscilloscope and an antenna with a good reflector around the antenna, you may need to assemble an amplifier on transistors, the higher the frequency, the more difficult it is to do this, since at high frequency even the layout of the board and solder matter. Antenna design is also according to the formula, length, width, etc.
And then sniff if you can recode the signal :)