I asked a similar question a while ago, but received no usable
> replies. I'll try again, in case anyone different is looking in.
> Apologies to all others.
>
> I want to generate repetitve test signals using a software frequency
> generator and sound card output.Theset may incorporate simple AM or FM
> modulation and/or an arbitray waveshape.
If it's the latter you want, then you want a (ta-da!) arbitrary waveform generator, aka AWG. They're commercial off-the-shelf items. But not cheap. Some plug into a PC, others are bench instruments, others are modules for plug-in test equipment.
Many DDS chips are easily AM or FM modulated, details vary but most at the very least support registers that set the amplitude and frequency
- update those registers to keep up with your modulation and you're done. DDS chips are a few bucks these days.
Tim.