Well, the spring-clip ground pins (included with the probes) help a little, compared with the alligator clip grounds (also included).
But I really cannot tell if this is just a super-sensitive scope, or if it's got a large inherent noise floor.
When switching the vertical capture resolutions, they seem to be using mechanical relays internally to switch portions of their amplifier circuit in/out.
There seem to be three vertical amplifier ranges: 100mV, 200mV, 500mV, and then, *click* 1V, 2V, 5V, and then *click* 10V, 20V, 50V. The cleanest signals, by quite a bit, are at the settings at the top end of each range, just before a *click*: 500mV and 5V.
The signal gets less noisy on the lower ranges. Eg. On the 1V range, the noise spread is often about 0.3Volts.. but zoom down to the *click* 500mV range, and the noise spread is now contained within a (approx) 150mV range.
Here's a capture off of pin-8 of one of the 74vsx04 chips, first with the spring ground tip on pin-7, and again with just the alligator clip many inches away on the empeg chassis.
EDIT: Well, that was interesting.. my CF-USB reader (for transferring photos) just tried to self-destruct -- it got *very* hot, and the chip markings inside the reader have blackened.. Switching back to the old reader now..
Cheers
Attachments
Description: Probing with the spring ground tip.Description: Probing with the alligator ground lead.Description: This shows the probe tip, with spring attached, and the alligator clip lead (not attached).
Edited by mlord (29/03/2008 13:41)