certain frequency artifacts appear in data

[ASakhno]

Chris, as for Your question about Dataq device - its bandwidth is 20 kHz, sample rate - 14400 Hz.

[ASakhno]

Thanks for the help. I have tried different configuration of scheme and sample rates, but everything are idle. It seems like this noise is really in my signal, indeed l don't register it by another daq device. So I will use filters or some other....

Thanks for all for Your answers.
Alexandr.