[aprssig] 60 Grid Squares for APRStt satellite?
kg4wsv at gmail.com
Fri Feb 13 19:27:10 CST 2015
There are 16 DTMF tones. 2 tones can represent any 8 bit ascii character. 4 tones can represent any 2 character grid prefix with no ambiguity.
More information about the aprssig