This is a pretty funny thread. I would concentrate on understanding why the scope is picking up this noise instead of trying to fix it. You might, in the process, learn a lot about why your audio circuits pick up noise.
The bottom line with 10x passive probes is they will pick up a ton of noise. You are basically running an antenna out of a sensitive amplifier into a hostile EM environment. The trace looks fine with the input grounded, which is as it should be. You also say the trace looks fine with an attenuating passive coax probe. That makes sense. 10x passive probes are just noisy as heck.
The bottom line with 10x passive probes is they will pick up a ton of noise. You are basically running an antenna out of a sensitive amplifier into a hostile EM environment. The trace looks fine with the input grounded, which is as it should be. You also say the trace looks fine with an attenuating passive coax probe. That makes sense. 10x passive probes are just noisy as heck.
Rear ground...
Try and find out what happens if you use the rear ground terminal of the scope. This is highly recomended for small signal measurements.
read article by RAPease on www.national.com
Gajanan
Try and find out what happens if you use the rear ground terminal of the scope. This is highly recomended for small signal measurements.
read article by RAPease on www.national.com
Gajanan
I think you are referring to this Pease story:
http://www.national.com/rap/Story/0,1562,18,00.html
... which was discussed in another thread, very like this one, only a week ago on this very website.
http://www.national.com/rap/Story/0,1562,18,00.html
... which was discussed in another thread, very like this one, only a week ago on this very website.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.