[Elecraft] Audio Ground Loop Isolation XFRMR?

[Fred Jensen]

The K3 has isolation transformers on LINE IN/OUT.  You don't need to add 
any more.  I assume you're using the term "ground-loop problems" in the 
generic [and somewhat archaic] sense.  Make sure that you're not using 
the shield of any of the cables [RF or AF] as the bond between your 
component's chassis' or enclosures.  They should all be directly bonded 
together.  If isolating the shields with external isolation transformers 
fixes the noise, that's a huge clue.

Finding the "chassis" on laptops can be a problem.  The hold-down nuts 
on DB or DE connectors are often [but not always] one place to get it. 
Unfortunately, those can be hard to find on some new laptops.

In stubborn cases, I'm told it sometimes helps if all the power cords 
connect to the same green wire too although I've never had to go that far.

73,

Fred K6DGW
-Sparks NV DM09dn

- Northern California Contest Club
- CU in the Cal QSO Party 1-2 Oct 2016
- www.cqp.org

On 9/19/2016 9:24 AM, dw wrote:

> Any way, I've been experiencing ground-loop noise from my PC.
> I've tried three different isolation transformers and they all work, but
> with significant signal loss from the PC.
> Does anyone have a suggestion?
>
> Thanks!
> N1BBR :-]