[Elecraft] Strange K3S/0 Mini Noise

[Don Wilhelm]

Mike,

Even though it may be complex, follow the paths of the audio and RF 
cables - what box connects to what other box - that defines the bonding 
path.

Do NOT use a star grounding system, it can actually make matters worse.
The hamshack of today is much different than those of prior times, and 
the old solutions for grounding and bonding do not work well today.
We used to have a microphone/key to the transmitter and then to a tuner, 
and then to an antenna.
Today's hamshack involves computers, soundcards, and remote control 
boxes as well as other miscellaneous gear, so the situation has 
changed.  In addition to the Pin 1 problem, the chances for pickup of 
hum, buzz and noise is increased 10 fold.

73,
Don W3FPR

On 12/13/2016 7:10 PM, Mike Murray wrote:
> Don,
>
> Thanks for the quick response and I suspect you are correct.  The 
> shack here resembles more than one octopus - I've got my work cut out 
> for me.  I've read and saved many of Jim's excellent articles so I'll 
> review them again and start there.
>
> 73,
> Mike
>
> On Tue, Dec 13, 2016 at 4:56 PM, Don Wilhelm <donwilh at embarqmail.com 
> <mailto:donwilh at embarqmail.com>> wrote:
>
>     Mike,
>
>     That sounds like hum, buzz and noise being picked up by the
>     connecting cables.
>
>     I would suggest that you follow Jim Brown's K9YC advice on bonding.
>     With heavy wire or braid, bond the various boxes following the
>     path(s) of the interconnecting cables and coax.  The bonding will
>     conduct that noise onto the outside of the various enclosures
>     instead of allowing the cable shields to conduct that noise into
>     the boxes and onto the ground plane.
>
>     In days of old when connectors were mounted directly on the
>     enclosure, this sort of thing was not a problem - noise pickup on
>     the cable shields was conducted onto the outside of the enclosures
>     and did not pose a problem.
>     In today's world, the shields of interconnecting cables are
>     connected directly to the ground plane inside the box containing
>     the circuits (pin 1 problem), and any noise picked up by the cable
>     shield is transmitted to the circuit ground plane.  The bonding
>     routes much of that noise onto the outside of the enclosure and
>     keeps it away from the circuits inside the box.
>
>     73,
>     Don W3FPR
>
>
>     On 12/13/2016 6:33 PM, Mike Murray wrote:
>
>         Since starting to use my K3/0 I've been bugged by a "buzz"
>         coming from the
>         speakers that I haven't been able to identify. Turning the
>         volume up
>         overrides the noise, but it's still there.  I've tried 3
>         different power
>         supplies with no change, including the one supplied by
>         Elecraft.  Here's a
>         recording of what I'm hearing:
>
>