Digital modes

I mentioned yesterday the necessity for hams to be conservative of spectrum by using efficient modulations for their communications.  There are a panoply of digital modes these days, with more being invented, and obviously these different modes have different characteristics in terms of spectral efficiency, performance, coding gain, and so forth.   W1HKJ (the author of the popular fldigi digital modem program) has a nice site that provides both waterfall images and sound samples of what various digital modes look and sound like, as well as brief descriptions of how each mode is produced and a very nice set of comparisons of the modes by various metrics.  Good reference for those trying to learn more about digital modes.

Thanks to Mark K6HX for the link.