[Elecraft] How is handkey plug wired for KX-1?

[Paul]

Most rigs that allow a hand key require it to be wired to a stereo plug 
using the sleeve and tip only.
I use CWType software and that sends cw out a serial port to a simple 
circuit with a switching transistor for on/off.
It works fine with other rigs.

However, when I plugged it into the KX-1, the 48 character index 
wouldn't go down as it sent my message.
I could hear the CW from CWType so I know that was working. And if I 
plug ina regular three wire paddle, and change the input from Hnd to 
Pdn, the paddle works.

As CWType is sending, I can see the KX-1 LED's blink a little, but the 
display stays on 48 characters.

I haven't found any words or wiring diagrams for a straight key; just 
"... plug it in ..." so maybe if Hnd is selected as input, it expects 
the ring connection to be shorted against the shaft; that is, a mono-plug.

And insights, advice as to why this software to serial port to switching 
circuit to stereo plug with ring unused to KX-1 with input set to Hnd 
wouldn't work.

Thank you and 73,
Paul, K7NHB