Bandwidth check of my oscilloscope with simple means ?

[David Hess]

One thing to keep in mind when testing probes like this is that at high frequency the >10pF of probe capacitance starts to really matter and can drag down a 50 Ohm source, but up to 100MHz it's still pretty reasonable.

15pF at 100MHz is ~100ohms. So much for such a probe being "high impedance 10Mohm"!

Indeed, probe bandwidth is specified with a 25 ohm source impedance and a coaxial connection to the probe tip, which is unrealistic for most real world usage up to 100 or even 200 MHz because of the inconvenience.

[rifkum]

I know this is a very old thread... but this is an interesting topic and new scope owners may be interested in the topic subject...

Alan is a very good teacher and here is his video on measuring scope bandwidth.
https://youtu.be/Ly5pmYopEfU?si=f5Q5FRmHvXZYNN_P

Cheers

[vk6zgo]

Of course you can never measure a waveform with a scope, only with a scope plus probes. There are many pitfalls for the unwary associated with poor probing technique.

So all those times I looked at signals coming out of the 50 Ohm or 75 ohm output of a DUT, (with the correct termination on the 'scope), I was doing it wrong?
Thread too old for my "smart comment" & besides, tggzzz has already addressed this point in a later posting.

[David Hess]

Of course you can never measure a waveform with a scope, only with a scope plus probes. There are many pitfalls for the unwary associated with poor probing technique.

So all those times I looked at signals coming out of the 50 Ohm or 75 ohm output of a DUT, (with the correct termination on the 'scope), I was doing it wrong?
Thread too old for my "smart comment" & besides, tggzzz has already addressed this point in a later posting.

If I had noticed it, then I would have addressed it.

I measure waveforms using an oscilloscope without a probe all of the time.  Indeed, I have never used a probe on my sampling oscilloscope.

Closer to the context of tggzzz's statement, many of my oscilloscopes return identical results when measuring the bandwidth of the instrument with and without a probe, but this will not be the case with all oscilloscopes.