I have strange interfearance on both channel sweeps with the probes disconnected and the inputs set on ground. If the vertical position is changed the interfearance goes away but may return at a differant position. This happens on both channels.
One can view a square wave by changing the vert pos tell the top and bottom are clean but this dont work for an analog signal like a sine wave. It looks like some kind of cross talk but why at only some vertical sweep setings. I have a pix but dont know how to upload it on this site.
If the variation is +/-1 bit, it is normal. It is caused by the operation of the AD converter and input amplifier noise.
Please see: viewtopic.php?t=899
[quote]I have a pix but dont know how to upload it on this site.[/quote]Sorry, this forum does not allow picture uploads.
You may upload pictures to a free hosting service (e.g. servimg.com/) and post the link here.
Its 4 volts on the 15 volt scale. that works out to 120v PP so 4v is about 4 bits. +or- 1 bit would be 120V/256 or about .5v. But you are telling me what the full scale error is and I have a channel thats shorted at the input. Are we not talking apples and oranges.
Only +/- 1 bit jitter should be acceptable.
This is +/-1/256 of full scale as you calculated.
Does the problem occur only when the inputs are shorted?
It would be informative if you can upload the pictures.
No need to upload full screenshots. - You can use oscilloscope’s File -> Save Image option and upload the .png image files.