[Elecraft] K3 PTT IN on back panel

[J.K. Hooper]

Are there any configuration settings required to use a foot switch connected to my K3's PTT IN RCA input on the back panel?    

The Config menu has a PTT-KEY setting, and default is OFF-OFF.    The setting can be RTS-OFF, or OFF-RTS, or RTS-DTS et al.   

Is this used for the PTT IN for a foot switch and which setting, I wonder.   

My foot switch is not working to key my Yamaha headset and I am trying to figure out why. 

Thanks in advance, 

73 
Hoop K9QJS  
San Juan Island, WA