[Elecraft] Weird KIO3UPKT problem

[Joe Subich, W4TV]

> as soon as the KIO3UPKT is plugged in I get the hum. The KIO3UPKT
> seems to function just fine in all other ways except for inducing
> this noise. Any ideas???
*BOND* the chassis of the K3/K3S, your computer, your power supply,
and your HiFi system together with a 1/2" braid, #12 or larger wire.
Make sure both the computer, power supply and HiFi supply are all
connected to the same outlet/back box.  SeeK9YC's excellent tutorial:
    <http://audiosystemsgroup.com/GroundingAndAudio.pdf>

73,

    ... Joe, W4TV


On 3/31/2018 12:40 PM, Fred Bennett wrote:
> Howdy folks...
> 
> I've been chasing this problem for a while thinking it was in my audio 
> system.....but NO!! I use a laptop computer with an external HIFI audio 
> board. The HIFI audio board drives a very nice amplified JBL speaker 
> system with a subwoofer. The external audio board occupies one USB port 
> on my laptop....when I plug the KIO3UPKT cord into any of the other 3 
> USB ports on my laptop I get what sounds like 60 cycle hum out of my 
> HIFI audio system. It doesn't matter which port I plug the HIFI audio 
> interface into....as soon as the KIO3UPKT is plugged in I get the hum. 
> The KIO3UPKT seems to function just fine in all other ways except for 
> inducing this noise. Any ideas???
> 
> 
> Stumped....   73...de   Fred  N9TA   Crawfordsville, IN.
> 
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