I have ordered a Flex 6400M and been reading the manual to get things ready for when it arrives. I am trying to figure out which RCA connector on the back will key my linear amp. It appears that it is either Connector 9, or any of TX1, 2 or 3. It appears connector 9, which the manual does reference as being for a linear? Please forgive the rather basic question but I just want to know how to connect the linear so that the rig will key it. My linear is a Tokyo Hy-Power 1.2KFX so it requires me to manually tune the band. So I just need to know which RCA connector on the 6400M will key the amp. I am very impressed with the company, the product, and the user group, so hope this question is not to basic for all the knowledgeable people here.