[TenTec] Paragon II RS-232 noise

[Jim Brown K9YC]

On Fri, 23 Jan 2009 08:49:47 -0800, jerome schatten wrote:

>Sounds like the computer and the rig are not at the same AC ground  
>potential. That is, if you measure the AC voltage between those  
>grounds, you may be surprised to see tens of volts.

I'd bet on a "pin 1 problem" at one or both ends of the cable. Study 
http://audiosystemsgroup.com/RFI-Ham.pdf   

especially "Solving Problems in the Shack" and the K9YC serial 
cable. 

Also look at the simple bonding recommended between the chassis of 
the rig and the chassis of the computer. This is also discussed in 
http://audiosystemsgroup.com/HamInterfacing.pdf  which contains the 
Power Point slides for several presentations of this material that 
I've done at ham clubs and hamfests. 

I'm currently writing the EMC chapter for the 2010 ARRL Handbook, 
and this material will be included. 

73,

Jim Brown K9YC