About 10 years ago I wrote an application that implemented
the serial tone modem which forms part of MIL-STD 188-110A.
It worked but the performance was never great and I couldn't be
bother to tweak it.
Well I am glad to say Steve N2CKH has taken up the challenge and after
many hundreds of hours with the program and a Rockwell HF
channel simulator he has managed to get the program to perform
within a whisker of hardware modems from the likes of
Rockwell, Harris etc. Well done Steve.
His application is for use in US MARS and the modem seems to be
proving its worth during exercises. I watch with interest as to
how things develop.