You don't necessarily need transformers. If grounds from both radios bonded 
together it should be fine, depending on extent of "pin 1" problem internal to 
radio. 

Two SPDT toggle switches would accomplish this. One switch for each ear which 
selects between the two radios. That's assuming you only care about mono 
sources. 

If you need isolation transformers use 1:1 or close to that. I can suggest an 
inexpensive transformer from Mouser/Digi if needed. You'll also need a 
headphone amp.

I would certainly try the trivial solution first and if noisy, try to correct 
the grounding issue before throwing hardware at it. 

73
Josh W6XU

Sent from my mobile device

> On Apr 25, 2018, at 10:54 AM, Rich <[email protected]> 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
> 
> ______________________________________________________________
> 

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]

Reply via email to