Where Amateur Radio Is Driving The State of the Art
FreeDV is a Digital Voice mode for HF radio. You can run FreeDV using a free GUI application for Windows, Linux and OSX that allows any SSB radio to be used for low-bit-rate digital voice.
Alternatively, you can buy a SM1000 FreeDV adaptor that allows you to run FreeDV (1600 and 700D modes) on any HF radio without a PC or sound card. If you are a hardware or software developer, you can integrate FreeDV into your project using the LGPL-licensed FreeDV API.
Links to freedv.org (17)
rowetel.comRowetel – open telephony software, hardware, critical thinking
areg.org.auAREG | Amateur Radio Experimenters Group
rfhead.netRF Head – HAB & Ham Radio Experimentation | Hamming it up since 2011!