I have owned a series of Futaba computer radios but the 8FG seems to be the least intuitive for me. I am setting up a RCxcel opto kill switch. I have an 8-channel Rc6208SB receiver. I need to setup a mix in my radio so I can kill the engine ignition from my radio. I placed placed the pmix on the rotary LD switch. I have the opto kill switch servo lead in channel 7. I assign the slave channel as AUX1. I can't seem to make the mix shut off the optotkill.

Assign it to switch SB in the lowest position.

Why do you need a mix? Just set channel 7 to the desired knob. You would do this in the Function section of the Linkage Menu. Adjust the endpoints of the channel so that the kill switch operates as you desire.

Thanks, Bax. You may be right. I think a problem could have been channel 7 was assigned to VPP I am going reassign it.

Bax got it to wokr on channel 7. It goes on and off with the LD knob. How ever if I shut off my radio the optokill led stays on. Do I need to set up a Failsafe for channel 7?

You can, and then the engine will kill when the receiver notices that reception is lost.