On Sun, 21 Sep 2008 20:42:27 -0400, Joe Subich, W4TV wrote:
>I think is it safe to treat the audio as band limited
That's like saying a driver is slow. How slow? Bandwidth limiting
CHANGES the complex impulse response of the system. It does not make
it not matter, or benign, just DIFFERENT. An
PM
> To: Jack Smith; Jim Brown
> Cc: Elecraft List
> Subject: Re: [Elecraft] K3 related - non-linear audio
> transformer behavior
>
>
> > That's why I question the applicability of a ringing test with a
> > square
> > wave having a rise/fall time measured i
That's why I question the applicability of a ringing test with a square
wave having a rise/fall time measured in nanoseconds, as the audio that
makes it through the K3's crystal and DSP will not remotely resemble that
waveform.
Agreed Jack, if the DSP and/or AF stages truly limit impulses thro
On Sun, 21 Sep 2008 13:31:00 -0400, Jack Smith wrote:
>Have you considered the difference between hitting a transformer with a
>fast rise / fast fall square wave and hitting it with one that is
>narrowly band limited?
That's one of the virtues of my measurement method -- it looks at the
respo
Have you considered the difference between hitting a transformer with a
fast rise / fast fall square wave and hitting it with one that is
narrowly band limited?
Ignoring for the moment the difference in filter shape between Gaussian
and the complex shape of the K3 crystal and DSP filters, the
On Sun, 21 Sep 2008 09:11:22 -0400, Paul Christensen wrote:
>the square-wave impulse response
>of the transformer becomes less meaningful.
As long as there is impulse noise, the square wave response of the
line out transformer is definitely relevant! As the folks at
Elecraft have noted, the pr
.
Paul, W9AC
- Original Message -
From: "Jack Smith" <[EMAIL PROTECTED]>
To: "Paul Christensen" <[EMAIL PROTECTED]>
Cc: "'Elecraft'"
Sent: Saturday, September 20, 2008 6:42 PM
Subject: Re: [Elecraft] K3 related - non-linear audio trans
Indeed, similar harmonic and IMD distortion are created inside the LINE
IN transformer. The question is their level and importance.
The LINE IN transformer, however, is fed by a 10:1 voltage divider, 604R
in series with 62R shunted across the transformer primary. This
arrangement provides a lo
Jack,
Thanks for the research - very interesting and it looks like a simple fix to
improve the performance of the K3 significantly. You've got me wondering now
though about DATA-A modes. As the K3 uses the same transformer for line in
your work suggests that the transmit performance will be affec
e - From: "Jack Smith"
<[EMAIL PROTECTED]>
To: "'Elecraft'"
Sent: Saturday, September 20, 2008 8:02 AM
Subject: [Elecraft] K3 related - non-linear audio transformer behavior
I've spent the last two weeks measuring and analyzing non-linear
behavior of s
d frequency response of the Bourns transformer changes significantly.
Tnx!
Paul, W9AC
- Original Message -
From: "Jack Smith" <[EMAIL PROTECTED]>
To: "'Elecraft'"
Sent: Saturday, September 20, 2008 8:02 AM
Subject: [Elecraft] K3 related - non-lin
I've spent the last two weeks measuring and analyzing non-linear
behavior of several audio transformers, focusing on the Tamura TTC-108
used as isolation transformers in the K3.
My data and analysis is now available at
http://www.cliftonlaboratories.com/non-linear_transformer_behavior.htm
J
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