Bnc ground to earth

Support & Troubleshooting Moku:Go
1

Hi. I have the moku go and have a question about the earth connection. I only have continuity between earth and bnc ground when the unit is off. Ones I turn the moku go on this continuity is lost. Is this normal or is there anything wrong with my unit?

When i use my scope a measure the output from the moku go waveform generator 75mV sinus 1khz the signal is shaky and noisy. If I measure a similar signal from another signal generator I have with the exact same setting on the scope the signal looks perfect.

This was the start of thinking something is wrong with the moku go and I then found the lack of earth connection on the bnc ground.

Do you have continuity between earth and bnc ground when your unit is on?

Thanks
/ Tom

2

Hi @Tom,

The ground of the power supply and the BNC’s are connected, they are not isolated or floating. The earth of the power supply is only connected to ground for safety and ESD compliance, it is not expected to have a direct connection between the power supply earth and the Moku:Go ground. For a stable signal, the oscilloscope ground needs to be connected to the Moku ground. Relying on the oscilloscope power supply and moku power supply earth to provide a common reference will result in shaky signals.

Cheers,
Nadia