[Elecraft] K3 RF Feedback Problem

[Paul Christensen]

>> L5 - Line In (J21);
>> L3- Line Out (J22);
>
> These are transformer isolated and not returned to frame or chassis ground 
> specifically to avoid ground loop problems.

Lyle,

That's right.  I should have looked "off page" on the preceding schematic to 
see that -- although the issue still stands on the other stated jacks. 
What's odd is that his RFI problem went away with the removal of L5.  I 
would not have expected that result on the transformer output although one 
line is shared commonly between two transformers.

Paul, W9AC