[Elecraft] serial interface noise on 160m -- propagates throughK3 to coax cables and grounds...

[Mike Harris]

Hi Mitch,

When I was chasing down an RS232 K3<>PC noise problem on 6M an homemade 
RS232 cable using CAT6 UTP to the K9YC spec cleared it completely.  I then 
tried the USB<>RS232 converter for comparison and it was noisier, the 
converter that is.

Regards,

Mike VP8NO

----- Original Message ----- 
From: "Mitch Mitchell" <mitchmitchell1616 at msn.com>
To: <elecraft at mailman.qth.net>
Sent: Monday, June 22, 2009 12:33 PM
Subject: Re: [Elecraft] serial interface noise on 160m -- propagates 
throughK3 to coax cables and grounds...


<snipo>
| I have been able to narrow the source of the noise down to the USB to 
Serial converters or the USB Hubs themselves.  The noise is getting into 
the ground through the serial interface on the K3 and then out to the coax 
shields.  I'll have to move a heavy desk to determine which of the two 
potential offenders is actually generating the noise.
|
| I was curious if anyone else had experienced this with a K3 and 
USB<->Serial converters -- the pulsing of the noise turns out to be HRD 
polling the K3 for VFO position -- once every 300ms -- and when I turn off 
polling the noise stabilizes but is still present.  I am doing research to 
see what I can do to eliminate it.
<snipo>