[Elecraft] K3 Key jack

[Craig - AE6RR]

I am using my K3/100 with the RemoteRig setup.  The RemoteRig Radio RRC has
a 1/8" or 3.5mm stereo connector for CW key out (straight key).  The cable
set came with a stereo 1/8" to 1/8" cable and a stereo 1/8" to 1/4" adaptor.
The 1/8" plug is a very loose fit in the adaptor and I am having
intermittent connection problems.

I am going to look for a better adaptor or make a 1/8" to 1/4" cable.

The question is, what kind of connector does the K3 have for key input (not
paddle)?  Is it a 3-conductor connector (stereo) or a 2-conductor (mono)
connector?

Happy New Year & 73,

Craig, AE6RR