Good point. There are some amplifiers I want to check as well. NF signal at preout should be 470mV and above. Or am I wrong at that point?
The audio signal coming out of my radio unit in my car should be around 6 V and above. That I will find out latest tomorrow... and that is something I want to check with the scope, too.
The CAN signal is 2 - 4 V. All scopes should handle that without problem.
When looking at the available scopes then at least I am doing things at the lower end of the lines and all of them in a range below 2000 Euro seems to be the "entry" stuff in different degrees. Would it be worth to spend 2000 Euro and more for me? I guess not.
The special price offer for the MSO2302 is gone now. The DSO2202 is still available, but the latest I have seen is around 1070. Therefor I can get a MSO5074 or a DHO1074. Hm...
I had no time today for a pre setup. Hope there will be within the next days.
For proper looking into CAN and FlexRay SI you would need a differential probe. To get decent results on 10MBit FlexRay 200MHz+ diff probe is preferred. Same with the scope. 100MHz should work for cursory check, but 200MHz+ would be preferred.
Make note that it is rise/fall time that is important, not actual frequency BW. Average 200MHz scope will have less than 1,8 ns risetime, and combined with 200 MHz probe (with similar risetime) will result in 2,5ns system risetime (they combine RMS) and that should be enough to measure 10 ns edges with cca. 3-4% error... 100MHz scope +100MHz probe (with 3ns risetimes estimated) would give cca. 8% errors..
You would need to check both signals in a pair single ended
and differentially to see if all is in spec.
You also need triggering for those protocols if you plan to look for specific things, like errors or specific packets.
Some scopes will also do eye diagrams and full characterization of SI on both protocols, but not in a price range we are discussing here.
There are quite a few whitepapers and info on SI testing on these protocols on Internet. I suggest a bit of dive into it to get a feeling how deep the rabbit hole goes and then decide how deep you want to go..