Recording Software

From 26 Apr 2004 we use the program Spectum Laboratory V2.4 b3


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 usedspectrogram” with the following settings:


Line in: to maximum sensitivity

Screen Resolution : 1152 x 864 x 16 bpp (now 1024 x 768)

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