[Elecraft] [OT] Headphone Splitter - Not The Kind You May Be Thinking

[Bob McGraw - K4TAX]

Ah, not  a good idea at all.  In using a "hard wire" type of Y cable, 
for your application, you will end up connecting the audio output of the 
K3 to the audio output of the KX3 through the Y cable.    I doubt that 
one radio will like driving the output stage of another radio and could 
damage one or both radios.

You will need some form of isolation system or amplification.   I 
suggest a small inexpensive mixing amplifier for the job.  For my 
application I use a Behringer UB 802.   The line level or aux output 
from each radio connects to a separate input of the mixer.  The 
headphones connect to the internal mixer headphone amp.  I can then 
control the level from each radio to the headphones and the headphone 
overall level.

As to using a Y cable to connect one CW key to two radios, you will be 
likely keying both radios at the same time, unless you take steps to 
have one radio off and one radio on.  Again, a Y connector is not the 
correct way to handle this method.

Better is to use a box that will switch the output of each radio to the 
headphones making sure that only one radio at a time can be selected.  
This also applies the the CW key.    Someone recently suggested using a 
two port printer switch, the one which has the 25 pin connectors on the 
rear.  These are also known as an A/B switch. Even  then you will have a 
good bit of wiring to accomplish.

Lazy is not the proper term.  Doing it correct is the proper method and 
a Y connector isn't it.

73
Bob, K4TAX

On 11/7/2015 2:05 PM, Joel Black wrote:
> The reason for wanting them is so I only have to use one set of headphones and CW key between my K3 and KX3. I guess I’m just lazy - I could just disconnect and re-connect depending on what rig I want to use.:)