Vesper - Confidential
10
Signal Quality Check:
Part 3/3 - Analyzing Noise Floor
•
You can check for RF interference
by plotting the FFT of the
Silence
Recording
. This is the VA1210
noise floor.
•
A clean noise floor (see
blue
curve)
looks like a
1/f
slope with a ~30dB
resonant peak at 4.5kHz.
•
If there is RF interference, it can
look like sharp peaks on the noise
floor (see
red
curve at 5-6kHz).
•
Bluetooth interference can be
identified by the noise frequency.
The peaks are usually multiples of
133Hz (i.e. 133Hz, 266Hz, 400Hz)
Clean VA1210 noise recording
VA1210 noise
recording with RF
interference
