[Elecraft] K3(s) Headphone Splitter

[john at kk9a.com]

There are many, here is one of the simplest designed for the ham market:
https://www.dunestar.com/store/product-info.php?pid12.html

John KK9A


Rich K3RWN wrote:  

I am planning to build a headphone splitter/switch so I can listen to 
one K3 in the left ear and the other radio in the right ear or turn off 
the audio from either radio.

Two questions:

Is there a commercial item for this purpose?

I know I will need an audio isolation transformer between each radio and 
the splitter/switch.   Any suggestions on what a good impedance value 
would be for those transformers?

Thanks

Rich

K3RWN