[Elecraft] K3 Keyer to use with Tascam interface

[Chris Meagher]

Hi
I have set up a Tascam US-125M with K3/10, for work with fl-digi.
Rather than use VOX, I would like to make a simple as possible circuit to
take the Tascam right channel output (carrying fl-digi keyer tone) to key
the K3 via the rear panel RCA,. Preferably electronic switching. Could use
a 9V battery?
Does anyone have a ready made circuit? Thanks.