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 <[email protected]
<mailto:[email protected]>> 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:
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