[Elecraft] K3 Birdie Screenshots

[Bill Johnson]

That was supposed to be 29.267  I must be 6/9 impaired J

 

 

73,

 

Bill

K9YEQ

K2 #35; KX1 #35; K3 #1744; mini mods

 

From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Bill Johnson
Sent: Thursday, February 12, 2009 3:14 PM
To: 'David Gilbert'
Cc: elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3 Birdie Screenshots

 

Dave,

 Great idea with the screen shots.  I have had the same success with the
Signal removal tool.  I have had only one that left a slight artifact on
26.267 mHz that really isn't an issue for my operation as it doesn't
interfere with my mode of operation and the width is only 50 Hz once I got
finished with it.  If it were in the way of anything, the tool that Wayne
has designed can be used to move the artifact.  The other two I have removed
so far are gone, period.  For what remains, the Auto Notch control takes
care of the rest.  Manual notch could also be used if one were on CW at that
Freq. which IMHO is unlikely.

 

73,

 

Bill

K9YEQ

K2 #35; KX1 #35; K3 #1744; mini mods

 

From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of David Gilbert
Sent: Thursday, February 12, 2009 2:56 PM
To: elecraft at mailman.qth.net
Subject: [Elecraft] K3 Birdie Screenshots

 


I've been beta testing using the new SIG RMV feature that Wayne developed
for shifting birdies out of the passband, and I must say I'm extremely
impressed.  It is very effective, and after addressing a handful of birdies
I found it very easy to use as well.  I have been able to totally remove all
of the birdies I considered even remotely an issue.  Where else would users
be able to expect that kind of support??

I've received quite a lot of feedback (all of it constructive, by the way) ,
though, that suggests that I am either being overly critical regarding what
I hear or that there may be a hardware problem (poor ground or other) with
my particular K3.  I would happily recalibrate my thinking if it is the
former, but I'd like to rule out the latter as well.  For that, we need a
less subjective assessment.

With a standard 1/8" audio cable from the Line Out connector of the K3 to
the Line In connector on my computer sound card, together with the free and
easy to use Spectrogram application
(http://www.visualizationsoftware.com/gram.html), it is quite simple get a
spectrum display of any birdie relative to the background noise in the
passband.  Spectrogram even lets you take screenshots directly from within
the application.  So I went back and found one of the birdies I had removed
with SIG RMV and cleared the settings to let the birdie sing again.  I've
uploaded the resulting Spectrogram screenshot to PhotoBucket, and it should
be viewable simply by clicking on the link below.

http://i228.photobucket.com/albums/ee141/xazdave/K3Birdie-7124r890.jpg

The frequency for this particular birdie is 7124.890 KHz, the mode was LSB,
the DSP passband was 2.2 KHz, the roofing filter was 2.8 Khz, the preamp was
OFF, and the antenna connector was terminated in a precision 50 ohm load.
The display indicates a birdie strength approximately 30 db greater than the
background audio noise level, although I wouldn't place too much credence in
the accuracy of that.  This birdie was roughly S2 (two solid bars) on the K3
S-meter, and it's one of six birdies of similar strength I had on 40m before
removing them with SIG RMV.

Comments or suggestions ...  even rude ones ;)  ....  would be appreciated,
particularly if anyone is willing to compare a Spectrogram plot for the
loudest birdie from their rig under similar conditions.

73,
Dave   AB7E








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