[Elecraft] K3 in NAQP SSB

[Jim Brown]

On Mon, 18 Aug 2008 15:35:55 -0400, W8JI Tom wrote:

>If the 12V supply has a ground connection common 
>to the negative lead post on the supply (or through other gear) the V- lead 
>voltage drop can cause a "pin 1" issue from dc potential that varies at an 
>audio rate.

YES!  
There's a similar problem on a lot of professional mix consoles, especially 
big ones with outboard power supplies. It shows up there in the form of 
hum/buzz issues. When we wrote AES48, we forgot about that mechanism, and 
didn't include it in the tutorial appendix. We'll probably add it when the 
Standard comes up for renewal in 2010. 

BTW -- several of us (including Joe Subich) have measured a significant DC 
voltage between connectors at the front and rear of the K3. This has the 
potential for doing exactly what you describe, depending on where that 
voltage appears in the circuitry! I built mine from the boards, and I took 
great pains to carefully install all the lockwashers and tighten all the 
screws. 

73,

Jim K9YC