Pot Noise - Grounding the board

[geoscash1]

Was wondering since I get noise when touching the external pots if grounding them to the aluminum case will eliminate that.

Would I use the 0v or the minus battery to use as the ground, I assume the 0v like using tp10?

anyone else ever have this issue and any help would be great explaining what causes it or why it does that on some boards and not others.

Thought about using copper tape on the back of the front panel, any ideas?

Thanks

[Koala]

I have had this problem on VLF detectors.

Always a good idea to earth the case an POTs to one central point. Not daisy chain


POTs with a metal central shaft often need a large knob fitting to completely eliminate


Coil shielding often makes it worse if you are using a metal case. On my IDX I had to insulate the coil connector from the case. Never did sort this out but the workaround has been fine for the last 3 years.

[geoscash1]

Hey thanks koala, much appreciated.

have had this issue a couple times but on some boards not so was wondering what the cause may be.

What I'll do is connect a wire to the 0v (tp10) to the case under a standoff for my board, that should work since the pots are
against the faceplate which is screwed to the case. My main coil isn't shielded although I do have one that will be used with this build that is so it should cover for both ways if I do it as mentioned above.

Or am I mistaking by connecting to 0v (reverse from norm, it is +vb (battery plus) on the mpp board) or should I connect to -vb (batt neg) ?

[Wahyu]

Any information about this? I have same issue

[Qiaozhi]

The reference point for all measurements on the MPP is the positive terminal of the battery. This is effectively 0V.