PSK 31 Apps for smartphones

[OpSecRadio]

That pretty much sums it up Scythe13 - and it definitely works well, we've had successful comms over 100km using this system with an android phone and a handheld radio hooked up to a small yagi.

A couple of the guys have even used it over a landline - sending PSK31 modulated sounds from mobile to mobile via the landline telephone system (no radio or mobile network) and it worked well, anyone listening in would just think it was a fax signal .