[Elecraft] Elecraft KX3 IQ out and spectral display pograms

[wb4jfi at knology.net]

I would check the splitter cable, or use another one.  I have had numerous 
times when the audio cable was not up to snuff (in different ways), and the 
results are I/Q imbalance issues.  I've even had Y adaptors from Radio Shack 
that were completely miswired.  You would think that simple cables could be 
relied upon, but I've seen otherwise.
Good luck.
73, Terry, WB4JFI


-----Original Message----- 
From: Chris Tate - N6WM
Sent: Saturday, December 20, 2014 2:13 PM
To: elecraft at mailman.qth.net
Subject: [Elecraft] Elecraft KX3 IQ out and spectral display pograms

Greetings and happy holidays Elecraft enthusiasts.

I have been putting together a portable contest/dx station using a 
KX3/KXPA100 combo.  What a wonderful little setup.  As part of my testing 
process, I have setup a laptop computer for rig control.  This works great 
in alot of respects,  Cat control.. no problem.  Keying cw from the 
computer.. no problem.  I have run into a tiny issue, regarding the IQ out 
and how it integrates with computer based spectral display applications and 
I am hoping the fine brain trust of audio experts can help me out.


I have a creative EM 0204, and I have split out the IQ stereo into 2 
channels using a 1/8 stereo to mono a/b splitter, and subsequently feed IQ 
to the EM 0204 into the L/R mono ports.  I am having some issues that I have 
not run into.. for instance when I used to do this using an N8LP pan with my 
K3.  (I have done sufficient testing with other computers, sound cards to be 
aware this is not limited to just this equipment).  here is what my 
observations are:

CW Skimmer.  Seems to work.. but the IQ balance seems to fall out of sync 
after being dialed in.  in other words from time to time multiple traces of 
signals appear.  this after adjusting with a fixed carrier on WWV to remove 
the traces.  Its almost as if there is an IQ instability of some kind and I 
was curious what others have found.

PAN displays, NAP3, etc.:  there seems to be a rather large artifact that 
tracks with the center frequency making use of the pan display rather 
impractical...maybe 20-30 Kc's or more.    I assume this issue is resolved 
to make the PX3 display an accurate spectral representation,  and so am 
wondering if there must be a setting or something I have adjusted 
incorrectly.

I also ran into an audio artifact where I could hear computer rfi through 
the headphones with the IQ cable plugged in..   I was able to mitigate this 
using a ground loop isolation cable..  keeping in mind I want to keep this 
setup portable and useable in remote locations.

IF anyone who may have resolved some of these IQ out issues could chime in 
and assist it would be greatly appreciated.  I am trying to make this setup 
as capable and portable as possible.

thanks in advance and look forward to your responses.

Chris
N6WM



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