Tom, I came across the post by you on the RTTY reflector last year where you were telling someone how to change the polarity of FSK on a TS-450. My dad gave me his TS-450 and I was going to check it out on RTTY. I'm guessing FSK input is on ACC2 pin 2 (RTK). Is this correct? Thanks! 73, Don AA5AU http://www.aa5au.com http://www.rttycontesting.com