[Elecraft] KIO3B Audio Spec

[Don Wilhelm]

Bob and all,

Bonding to a common point may not cure hum and buzz.
Follow the advice of Jim Brown K9YC and bond from equipment to equipment 
- following the path of the shields on unbalanced audio cables and RF coax.
In other words, bond from the computer to the K3 (or from the computer 
to any interface box, and then the interface box to the K3).  The K3 to 
amplifier if present, then to the tuner if present.

The bonding wires will take the majority of the current that *might* 
otherwise flow on the shield of those cables and reduce the possibility 
of noise coupling into the signals.

Whether you also bond to a common point in the station is an entirely 
different matter.  That common point ground may do well for AC safety 
and possible a measure of lightning protection, it will do nothing for 
the coupling of hum and buzz onto the signal paths.

Jim often talks about the "pin 1 problem" which is part of the 
situation, but providing an extra low impedance path direct from 
equipment to equipment will do more to keep all pieces of your equipment 
at the same relative potential than any other means.

73,
Don W3FPR

On 12/31/2015 6:36 PM, Bob McGraw - K4TAX wrote:
> Yes, this is correct.
>
> I have all of my station equipment bonded to the common point on the 
> station power supply.   And I do not use any "ground" to the outside 
> world from my 2nd floor station.  Works just great, all bands 160M - 
> 23 cm, any power level to legal limit, any mode.
>
> 73
> Bob, K4TAX
>
> On 12/31/2015 5:10 PM, Jim Brown wrote:
>> On Thu,12/31/2015 11:29 AM, Barry N1EU wrote:
>>> You'll get hum if your computer and K3 chassis aren't at the same 
>>> ground potential.
>>