[CQ-Contest] SSB Voice Keying

[Jim Brown]

On Wed,3/2/2016 7:35 AM, Katsuhiro Kondou wrote:
> I have a plan to use an audio shield (velleman KA02) using ISD1700 for Arduino.
> Builtin switches on the shield will not be used, and it will be controlled via
> USB serial so that logging software can handle.

A cable shield must NEVER be connected to anything but the shielding 
enclosure at the point of entry. Putting that another way, a cable 
shield must ALWAYS be connected directly to the shielding enclosure at 
both ends. Anything else is a source of hum, buzz, and RFI.

Yes, I know that nearly all ham rigs fail to do this, but the 
manufacturers are WRONG. For engineering analysis of this, see my 
tutorials on "The Pin One Problem" on my website, also the AES Papers on 
my website, and the tutorial appendix to AES48, which can be downloaded 
from the AES Standards website (but not free).

73, Jim K9YC