oscilloscope probe questions

Yes....you need to match the time constant in the scope (R*C) with that of your probes. Most probes are 1Mohm and they have a small variable capacitance that you can adjust with a screw driver. If you have too much capacitance on the probe, the probe scope interface will act as a high pass filter and too little capacitance it will act as a low pass filter. Generally you calibrate the probes with what you know is good quality square wave so that you see straight sides and a flat top on your scope.

You can also get probes that you can switch between 1Megohm and 10Meg ohms which is a good idea....the higher the input impedance to the scope the less likely you are to effect the circuit being measured. Once you switch to 10Megohms you might need to recalibrate the probe though.

Nah. Just get a oscilloscope probe*. 1 Megohm 47 pF is the impedance of the scope. If you stick a ohmmeter to the inputs of your scope, 1 megohm is what you'll get.

Note that if your scope plugs into wall AC receptacle, the chassis is earth grounded. Therefore, the ground clip/hook is also earth grounded. So don't connect ground clip/hook to non-zero source/signal!

Steve Minshull wrote in news:e13dae$fnm$ snipped-for-privacy@hermes.shef.ac.uk:

It's the 10 Megohm probes (10X) that have the comp adjustment,1Meg probes(1X) are little more than coax with a fancy tip,and a lot of capacitance.

Yes,less resistive and capacitive loading on the circuit under test.

You adjust it at 10X,not at 1X.