[Elecraft] K3 / P3 with SteppIR

[Larry Gerhardstein]

I have a K3 / P3 / SteppIR SDA100.  Everything is set to 38400 baud.  I 
have connected a Y-cable to the RS232 connection on the K3.  One side of 
the Y is connected to the SteppIR controller with a null modem inserted 
(as directed by SteppIR instructions).  The other side is connected to 
the XCVR connection on the P3.  Both work, but not at the same time.  
Unplugging one of the Y connections makes the other work, and visa 
versa.  Any ideas?  Perhaps there is a special & splitter that will 
provide the necessary isolation??  Or perhaps I need to orient the Y a 
different way??

Larry W7IN