4 ms·
Your point still stands but the noise here is effectively a higher frequency modulation of the base AC oscillation. In other words, the base oscillation of 50
by FPGAhacker 4y ago
Your point still stands but the noise here is effectively a higher frequency modulation of the base AC oscillation.
In other words, the base oscillation of 50 or 60 Hz is not stable, but instead varies a little above and a little below at higher rates.
The magnitude is significantly lower than the base mains frequency. So possibly not audible above any other noise in the recording, but present nonetheless.
- ok123456 4y agoThese filters will take that into account since it never has exactly been 50/60Hz. It's just the expected mean. Maybe it's present in subsequent harmonics (e.g., 100/150/200Hz for 50Hz) as a systematic deviation from additive white noise. But, this would be difficult in practice to reliably isolate these signals via some form of component analysis.