[Elecraft] [K3] Shorting K3 PHONE jack outputs (WAS OT: Stereo to mono adapters)

[Joe Subich, W4TV]

>> With that said, is it safe to bridge the L&R channels coming out of
>> the K3'sphone jacks, front or rear panel without fear of damaging
>> the amplifier? The ANEM presents a 22 ohm load to the K3.

Yes, it is safe to sum the *headphone* jacks since both the front and
rear panel headphone jacks include 8.4 Ohm resistors in series with
each (tip and ring) output.

*WARNING* do not sum the Speaker output or use a mono cable in the
speaker jack as the speaker output does not include any resistor and
shorting an output (or driving power into an unused output) can
destroy the speaker amplifier.

73,

    ... Joe, W4TV

On 12/3/2010 11:29 AM, James Sarte (K2QI) wrote:
> Hello group,
>
> Just wanted to get some advise before I continue with my experiment.
>
> I recently received a new BHI ANEM AF DSP module.  It is a mono-only device
> and as such, is supplied with a mono 3.5mm patch cable.
>
> Plugging that cable into the K3 only gives me audio to the left channel.
> The right channel or ring, I assume is left floating.
>
> This morning, I stopped by Radio Shack and purchased a stereo to mono
> adapter that essentially shorts tip and ring thus channeling both L&R
> sources into one.  With this adapter, I can hear both main and sub receivers
> in my left ear.
>
> I however would like to be able to hear the main RX in both ears, so I
> purchased another adapter: mono plug to stereo jack.
>
> Basically, the connections will be like this:
>
> [K3]-->[stereo to mono adapter]--->[mono patch cable]--->[ANEM
> DSP]---->[mono to stereo adapter]---->[Headphones]
>
> With that said, is it safe to bridge the L&R channels coming out of the K3's
> phone jacks, front or rear panel without fear of damaging the amplifier?
> The ANEM presents a 22 ohm load to the K3.
>
> Mni tnx,
> James K2QI
>
>
> On Fri, Dec 3, 2010 at 7:04 AM, Monty Shultes<montys at mindspring.com>  wrote:
>
>> James, such an adapter would short the stereo outputs together unless it
>> were an active mixer.  I doubt that it exists.
>> Monty K2DLJ
>>
>>
>>> Does anyone know the part number of a Radio Shack or equivalent 3.5mm
>> stereo
>>> male to 3.5mm mono female adapter that will bridge both L&  R channels
>> into
>>> a single mono source?
>>>
>>> --
>>> 73 de James K2QI
>>> President UNARC/4U1UN
>>> ______________________________________________________________
>>
>>
>
>