This program was written as a help for learning and understanding the FFT properties. The supported functions cover the practical and theoretical field. The program requirements are:

* Windows 95.
* 400k disk space.
* No installation required (just unzip);
* This is shareware. Source code on registration.
* distribution is free
* Author's Email: janez.makovsek@usa.net.

The following functions are supported:

1. Two displays: Time signal, Frequency Spectrum.
2. Power Spectrum
3. RMS Spectrum
4. Phase Spectrum
5. Three input signals support.
6. Separate adjustment of DC, Phase, Frequency and Amplitude.
7. Real time emulation. (Smooth animation)
8. Log/Lin Scale.
9. Static/Dynamic Scale.
10. Single/dual screen display.

Signal generator:

* Sinus
* Impuls
* Triangle
* Square
* Transient

FFT Windows

* Rectangular
* Hamming
* Hanning
* Blackman
* Exponent Down.

The following phenomena can be observed:

* FFT and signal type.
* FFT and Window type. 
* Amplitude accuracy at different Windows.
* Frequency accuracy at different Windows.
* Power and RMS Amplitude towards normal.
* Phase spectrum and Windows.
* Beatting of Amplitude in real time.
* The effect of DC and relation of DC towards signal average.
* FFT aliasing.
* Time signal aliasing. (Sampling)
* The effect of convolution: time signal and rectangular window. ZOOM-ed in FFT. (FFT oversampling.)
* The effect of non-integer number of periods per Window. (In amplitude and Phase)
* Higher harmonics and aliasing.

Some things were left out and will be added if enough of interest will be shown:

* Resolution-TimeSignalLength - FFTsize relations.
* FFT BandWidth.
* Saving the settings.
* Extended documentation on different phenomena.
* Signal aquisition on multi-channels with National Instrument DAQ boards.

Currently no extended documentation is available on the theory of the phenomena. However the properties can be directly observed, and if properly commented, also very well understood. 

And somethings are still in the drawer (not beeing a part of FFT properties directly)  such as:

* Cepstrum
* AutoCorrelation
* CrossCorrelation
* Digital filters



