From 26 Apr 2004 we use the program Spectum Laboratory V2.4 b3
Settings:
Spectrum: 0 - 105 Hz
Waterfall scroll interval: 7500 msec
FFT input size: 65536
FFT window function: Hanning
Audio sample rate: 5512
Display Amplitude Range: -70 to -50 dB
Noise blanker: ON (Ramp time = 1 sec , Trigger peak/avrg = 20 dB , Max.
pulse width = 0.5 sec)
FFT filter: ON (for spectrum equalization)-(Band reject, Center/cutoff=21
Hz, Bandwidth=6 Hz, Slope width=90 Hz, FFT size=512)
Image show how filters used in the program
In
the past we have used
“spectrogram” with the
following settings:
Line
in: to maximum sensitivity
Screen
Resolution : 1152 x 864 x 16 bpp
Tracing
Form F.F.T
Signal
scale: - 30 db
Sample
rate: 5,5 KHz 16bit
F.F.T.
points : 16.384,
Linear
frequency scale
Average
count: 1
Pitch
Detector: off
Time
scale: 6250 msec
In
order to save the images, I use program “2020”
(now ScreenHunter 4.1 pro) with the following settings:
Capture:
Desktop – scrolled area
Auto
save
Auto
increment
PNG
(Image format)
Time
capture: 7200 sec (2 hours)
Rectangle Repeat
