http://download.cnet.com/Spectro-Signal-Generator/3000-2056_4-10858133.html
there is a version for mobile computers too! Don't let not having a signal generator stop your efforts!
ANYONE who finds other software test equipment please link it. I hear there are voltage/O scope/amp packs and usb mods for the input/outputs any links will help all thank you!
IT is free to try within a 30 day trial time, then it costs $11
It does not turn out from the specifications if the duty cycle of the output waveform is also adjustable or not. IT surely turns out when you download and run it... but why is not it specified in its description?
Nevertheless, it is surely better to have if it is needed.
EDIT:
Here is a really free oscilloscope software for the sound card:
http://www.zeitnitz.de/Christian/scope_en
This scope software includes a signal generator too...and is able to do frequency (spectrum) analysis and wave file recording.
The signal generator in the latest 1.32 version does have a variable duty cycle feature, from 1% to 99%.
rgds, Gyula
any chance there is a signal generator out there that has the ability to use multiple sound cards? not to see a signal but create one and each output being independent of each other. This is not really for over unity but is related to utilizing it.
I have just written him an email asking if it will
address multiple cards like an OS does.
http://www.zeitnitz.de/Christian/scope_en
Honestly, there is a snowstorm of apps for this.
http://www.google.com/webhp?hl=en&newwindow=1&num=100&lr=lang_en&safe=off&q=#num=100&hl=en&newwindow=1&safe=off&q=Multiple.Sound.Card+Signal.Generator
There are various apps here that are useful:
http://www.techmind.org/audio/
http://www.dxzone.com/catalog/Software/Signal_Generator/
http://www.dxzone.com/catalog/Software/Spectrum_analyzers/
http://www.filesland.com/download/signal-generator.html
http://www.epanorama.net/links/pc_sound.html#specialuse
A mixed mash here,
but the pocket-PC gen/scope might be nice to try:
http://www.fileguru.com/apps/psn_card_generator
"(3) - Wave-form generator
* Dual channel
* Independent sampling frequency/resolution from scope/spectrum (up to 192 Khz/24 bit)
* Phase between channels (degree)
* Direct real time generation/ loop with predefined buffer
* Waveform CUSTOM, built with harmonics (with save/load in file ".fun" of defined waveform)
* Modulation of custom waveform with sinus/square/triangular
* Predefined waveform : sinus, square, triangular (parametric), white noise, pink noise, pulse, sinusoidal sweep
* Local volume levels
* Real time parameters variation (amplitude, frequency, phase between channels, type of waveform) "
+ free ....
http://www.sillanumsoft.org/prod01.htm