Click on a digital mode to hear a brief (most <100 kilobytes) sample of the sound these modes make. Hopefully this link will help you identify a mode you've heard (or help me identify ones I've heard!). Many folks have submitted excellent quality, lengthy files which are no trouble for me to accept, but I do generally drop the sampling rate and length to make them more reasonable to download over a dial-up line. The intent here is more for recognition by ear than for signal analysis. I have higher quality samples of some files, please email me to request them (up to 3MB). http://kb9ukd.com/digital/