[Elecraft] Re: K3 & MK2R+ audio hum issue (TOO LONG)

[Jim Brown]

On Sun, 31 Aug 2008 09:32:51 -0500, Bob Evans wrote:

>The manual was not written with "ease of use" in mind and you are 
>referred to "outside experts" to get a complete history of ground 
>loops rather than tucking a few "good practices" into the manual.

I don't know anything specific about the MK2R, but many (most?) ham 
and computer audio products are built with very WRONG grounding 
practices. Indeed, most ham transceivers, including the K3, do some or 
all of this stuff wrong!  

There's a lot of VERY wrong thinking about hum, buzz, and ground 
loops, and that has led many folks to some really dumb practices that 
often CAUSE problems rather than solving them (and that are often a 
lot more expensive than solving the real problem). 

To understand what's REALLY going on with so-called "ground loops" 
(and some VERY low cost solutions), have a look at 

http://audiosystemsgroup.com/RFI-Ham.pdf  

and 

http://audiosystemsgroup.com/HamInterfacing.pdf

73,

Jim Brown K9YC