Preface, why am I asking this question?
Instead of using a passive probe with a ground clip, I want a more "permanent" and reliable connection for my measurements. Note: I'm not talking about RF, just regular measurements you would do with a passive probe.
For this reason I'm considering using a UMCC connector on my PCB, something like this:
Also quoting an answer from "Oscilloscope: when to use coaxial instead of probes?" (emphasis mine):
Basically, when it is possible to use coaxial, use it. Coaxial connectors are more reliable than a probe. With a probe, you need to hook it to a test pin or even sometimes hold it in place. You have a grater risk of slipping off of your test point or getting a dodgy connection. With a probe you also get ground from 'somewhere' but not necessarily at the right place. On a coax, you get ground from the connector, where it should be. (this can matter when propagation times become relevant)
My question:
I really have a hard time finding anything on the question I'm having:
So as far as I know there are 50Ω50 Ω and 75Ω75 Ω coax cables. I know that this isn't the DC resistance but the characteristic impedance. Now, since I don't want to load my signals with a 50Ω50 Ω termination load (which the oscilloscope does when set to a 50Ω50 Ω input) I want to have a high impedance input like 1MΩ1 MΩ or 10MΩ10 MΩ, but with the coax connection.
Basically, I want to replace the passive probe with a coax, so I get a reliable connection -— but what about the impedance of the coax cable? Does it matter for signals that are not RF? Because I can't find anything on that topic, really.
Is it okay to use a 50Ω50 Ω coax connection for non-RF signals into a scope with 1MΩ1 MΩ /10MΩ 10 MΩ input impedance without a load termination resistor?
My assumption is that it'll be okay since the DC resistance of the coax is minimal.
However, I'd like to have this confirmed by someone who has more experience than me.