Harmonic Distortion

[Mike Scott-7]

>Taking all of this into account, I run my LIN OUT gain at 3, and
recommend that setting.

Jim B., I also confirm your analysis with my serial number 508 K3. I don't
have your equipment but I was able to see the effects that your well-done
reports show. The freeware signal analysis software Spectrum Lab is quite
good enough to see the effects and that led me to exact same conclusion,
above a gain of 3 the Line Out distortion effects become quite noticeable.

I know that LIN OUT and AGC settings might interplay, so for what it is
worth I run LIN OUT gain at 3, AGC SLP = 10, AGC THR = 6. Other parameters
are default.

My sound card gain is now set to maximum. I believe it would be a lot
happier if there was more drive. I think maximum soundcard gain with low
signal drive makes what ever noise pickup that exists on my cables more
obvious as I have a lot of spikes (60-hz multiples) showing outside the
filter pass band just 18 dB below the general tops of the in-band noise
spectrum.

Mike Scott - AE6WA
Tarzana, CA (DM04 / near LA)
K3-100 #508/ KX1  #1311



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[Jim Brown-10]

On Tue, 2 Sep 2008 11:36:19 -0700, Mike Scott wrote:

>I know that LIN OUT and AGC settings might interplay,

Yes.

>so for what it is
>worth I run LIN OUT gain at 3, AGC SLP = 10, AGC THR = 6. Other parameters
>are default.

I haven't studied what the ideal settings are, but I would follow Lyle's
guidelines for strong signal conditions.

>My sound card gain is now set to maximum. I believe it would be a lot
>happier if there was more drive. I think maximum soundcard gain with low
>signal drive makes what ever noise pickup that exists on my cables more
>obvious as I have a lot of spikes (60-hz multiples) showing outside the
>filter pass band just 18 dB below the general tops of the in-band noise
>spectrum.

See my Power Point on how to kill this noise by bonding together the
chassis of the computer to the chassis of the rig. It's easy, cheap, and
very effective.

http://audiosystemsgroup.com/HamInterfacing.pdf

and the same stuff as text in

http://audiosystemsgroup.com/RFI-Ham.pdf 

73,

Jim K9YC


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