[Elecraft] K2 Audio Loss Due to ESD

[Jim Brown]

On Wed, 13 Apr 2005 16:56:50 -0400, Roy Morris wrote:

>I have come up with what I think is a better mod for grounding 
>the mike connector 

The ONLY good place to connect the shield of the mic cable is to 
the chassis of the K2. I have modified one of my K2's to do this, 
and will do the other one (newly acquired) soon. When you connect 
the shield to the circuit board and from there go to the chassis, 
you set up what we in the pro audio world know as a "pin 1 
problem."

You can find a tutorial on this as part of AES48, an international 
standard that I helped write. At www.aes.org, go to Standards, 
then Standards in print, and then select AES48. Anyone can 
download a pdf of the standard at no charge. If you are not an AES 
(Audio Engineering Society) member, you won't be able to print the 
pdf, but you can read it on your screen. You can buy a printable 
copy for $25. 

BTW, the chassis is also the "right" place to connect the signal 
return of RS232 connections, NOT pin 5. I've solved some serious 
RFI problems by correcting this. 

This is a tutorial on the topic. 

http://audiosystemsgroup.com/FerritesRFI-HamPPT.pdf 

There are other tutorials on the website that you may find 
helpful.

http://audiosystemsgroup.com/publish.htm

Jim Brown  K9YC