Please check my webpage for information on the TS-850S and FSK. http://www.qsl.net/k0bx Also the following is the interface for ptt/fsk that I use with my TS-850S. I find the transistors easier to work with. http://www.w5bbr.com/pttfsk.html Good Luck K0BX Joe -- WWW: http://www.writelog.com/ Submissions: writelog@contesting.com Administrative requests: writelog-REQUEST@contesting.com Problems: owner-writelog@contesting.com