Rich wrote:
I am not an audiologist (?) but isn't a harmonic that is 45db below the
fundamental tone essentially non-detectable to normal hearing? Kind of why
the harmonics of a RF carrier are to be 40dbs down.
The transmitter limits are legislative/engineering compromises. They
reflect
: Re: [Elecraft] K3 Harmonic Distortion
To: David Cutter [EMAIL PROTECTED]
Cc: elecraft@mailman.qth.net, Leigh L. Klotz, Jr WA5ZNU
[EMAIL PROTECTED], Julian, G4ILO [EMAIL PROTECTED]
Message-ID: [EMAIL PROTECTED]
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
David:
Even
As near as I can see from tracing from one sheet to another, U29, a
TLV320ACC23 DAC with integrated headphone amplifier drives the TTC-108
LIN OUT transformers directly. Headphone and speaker audio, in contrast,
are derived from a second TLV320 DAC driving a LM4950 amplifier for
speaker
...I believe the device listed as U29 on the K3 schematic may be a
mis-print and my best guess is that's it's the Texas Instruments TLV320AIC23
-- as is the case with U7.
The schematic is correct, U29 is a TLV320DAC23.
73,
Lyle KK7P
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Elecraft
Hmmmmy schematic shows TLV320ACC23 for U29.
Paul, W9AC
- Original Message -
From: Lyle Johnson [EMAIL PROTECTED]
To: P.B. Christensen [EMAIL PROTECTED]
Cc: elecraft@mailman.qth.net
Sent: Friday, September 05, 2008 1:22 PM
Subject: Re: [Elecraft] K3 Harmonic Distortion
...I
Paul Christensen wrote:
Hmmmmy schematic shows TLV320ACC23 for U29.
I see that, too. The D is missing.
Lyle
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I am not an audiologist (?) but isn't a harmonic that is 45db below the
fundamental tone essentially non-detectable to normal hearing? Kind of why
the harmonics of a RF carrier are to be 40dbs down.
Rich
--
View this message in context:
On Fri, 5 Sep 2008 17:51:42 -0700 (PDT), Rich wrote:
I am not an audiologist (?) but isn't a harmonic that is 45db below the
fundamental tone essentially non-detectable to normal hearing?
It depends on the order of the harmonic. There are studio processors that
INTENTIONALLY generate 2nd
The measurements that have been made seem to suggest that the problem is not
regular distortion or clipping. I am wondering if it is some kind of
quantisation effect due to the fact that the signal processing is digital or
analog? I am thinking of the fact that there are people who claim that
This may be a glass half full response but being an old hearing impaired guy
has it's positives:
1. Ignoring XYL when needed and excusing it by pointing to hearing aids.
2. Sleeping like a baby every night with said hearing aids removed.
3. Not hearing any distortion in my K3.
Life is good
I haven't done the sort of testing that you must do for your applications,
but I've used the OEP8000 transformers in several applications with good
results for speech only. I've no idea of its high frequency response. They
are tiny in comparison.
The problems people are having with harmonics when they listen to CW
with a 2.7KHz filter/DSP setting seem to be easily solved by just reducing
the DSP bandwidth.
If you were paying attention to the spectrogram plots you would have noticed
that the IMD and harmonic products are showing up far
, 2008 5:20 AM
To: elecraft@mailman.qth.net
Subject: RE: [Elecraft] K3 Harmonic Distortion
The measurements that have been made seem to suggest that the
problem is not regular distortion or clipping. I am wondering
if it is some kind of quantisation effect due to the fact
that the signal
VP8NO writes:
Perhaps someone suitably qualified and tooled up might like to try and
[repeat] and comment upon the view presented by Rob Sherwood at the
Dayton convention. According to him the K3 audio amp stage has
serious shortcomings.
I had to listen to the audio of Sherwood's talk
Clearly I must be missing something.
In my view, all the reported distortion numbers are beyond expectations.
After all you are buying a $2K radio, not a many kilobuck audio system.
The problems people are having with harmonics when they listen to CW
with a 2.7KHz filter/DSP setting seem to be
: [Elecraft] K3 Harmonic Distortion
Clearly I must be missing something.
In my view, all the reported distortion numbers are beyond
expectations. After all you are buying a $2K radio, not a
many kilobuck audio system.
The problems people are having with harmonics when they
listen
Joe Subich, W4TV-3 wrote:
The solution is simply not pushing the output gain and keeping
the output under 1V peak and use high impedance devices. With
the speaker amplifier 800 mW into a 16 Ohm speaker shows less
than .01% THD+N - if more audio is necessary 1V peak will easily
drive a
The spectrum display you sent me shows an excessive level of
50 Hz harmonics - some 15 dB above the noise floor and only
40 dB below the desired signal from 150 Hz to above 3 KHz.
That strongly indicates serious grounding issues, power supply
filtering problems, improper power supply
: Jim Brown [EMAIL PROTECTED]
To: Elecraft List elecraft@mailman.qth.net
Sent: Monday, September 01, 2008 11:45 PM
Subject: Re: [Elecraft] K3 Harmonic Distortion
| On Mon, 01 Sep 2008 18:45:36 -0400, Jack Smith wrote:
|
| I've found that the LIN OUT port has typical third harmonic levels
| around -45
Anyway, the noise/distortion is still there coming out of the
headphone socket.
Berni, this is a technical group and as such we need hard data and not
subjective descriptions of what you hear coming out of the headphone jack. I
don't doubt that you are hearing something. There is very little I
It would be nice to see this problem with the the K3IO board addressed
at some point. It may be, as Jim K9YC has hinted, related to core
saturation from low frequency components that could attenuated before
reaching the board. Or it may be that the transformers that fit in the
space are as
Working through the K3's schematic this morning, it seems that both the
headphone output port and the LIN OUT port are driven by similar
devices, a Texas Instruments DAC with integrated headphone amplifier.
(Two DACs, one for LIN OUT and one for headphones and speaker output.)
As near as I
Jack
I have seen postings on the main reflector recommending settings as low
as 3 to avoid distortion products that are being attributed to
transformer distortion. This did not really make sense to me, especially
at such low levels where consumer sound cards tend to get non-linear and
nasty.
I
On Tue, 02 Sep 2008 11:53:23 -0400, Jack Smith wrote:
The solution of choice in my opinion for the
Softrock receivers turns out to be a MILSPEC Triad transformer, SP-70,
with excellent frequency response and quite low distortion. In single
lot prices, an SD-70 costs about four times as much as
Brendan:
You might wish to look at the measurements I made, with LIN OUT settings
from 2 to 100. There's an animated GIF that steps through the LIN OUT
settings so you can see the effect. The data was taken at 600 Hz.
http://www.cliftonlaboratories.com/elecraft_k3_receive_audio.htm about
There are three distinct audio channels in the K3, and they all have
slightly different characteristics.
LINE OUT
This has its own digital-to-analog converter (DAC) and is transformer
isolated.
PHONES
This shares a DAC with the speaker channel, but has its own amplifier
and isolating
On Tue, 2008-09-02 at 12:28 -0400, Jack Smith wrote:
However, setting the LIN OUT at 2 results in quite a bit better odd
order harmonic suppression, on the order of nearly 70 dB.
This might be due to simply running out of usable bits to represent
accurately the harmonics at the low end of
Date: Tue, 02 Sep 2008 09:34:31 -0700
From: Lyle Johnson [EMAIL PROTECTED]
There are three distinct audio channels in the K3, and they all have
slightly different characteristics.
LINE OUT
This has its own digital-to-analog converter (DAC) and is transformer
isolated.
There are three distinct stereo audio channels in the K3, and they all
have slightly different characteristics.
LINE OUT
This has its own digital-to-analog converter (DAC) and is transformer
isolated.
PHONES
This shares a DAC with the speaker channel, but has its own amplifier
and
I find virtually the same results here using 50uV RF from an
Elecraft signal source, and measuring using Wave Spectra.
An offset of 43 to 45dB, and below LIN OUT = 5 the harmonics drop
rapidly.
73
Stewart G3RXQ
On Tue, 02 Sep 2008 12:28:02 -0400, Jack Smith wrote:
Brendan:
You might wish to
On Tue, 02 Sep 2008 17:06:29 +0100, Brendan Minish wrote:
I used an old copy of SMAART pro that I have from my Sound
engineering
days.
I have that software, and have long used it to analyze ham filters.
the sound card is a delta44
I don't know this card, but it's own noise floor (or input
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
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
Hi Lyle,
only to be sure - if I have in CONFIG: LINE OUT - PHONES which D/A is
used - this one for SP/PHONES ?
Then LINE OUT level is controlled by AF knob so I suppose that PH/SP
channel is used but not sure.
Thanks
Lexa, OK1DST
Lyle Johnson napsal(a):
There are three distinct stereo
only to be sure - if I have in CONFIG: LINE OUT - PHONES which D/A is
used - this one for SP/PHONES ?
LINE OUT is always driven by the LINE OUT DAC.
73,
Lyle KK7P
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: Elecraft
Subject: Re: [Elecraft] K3 Harmonic Distortion
I find virtually the same results here using 50uV RF from an
Elecraft signal source, and measuring using Wave Spectra.
An offset of 43 to 45dB, and below LIN OUT = 5 the harmonics drop
rapidly.
73
Stewart G3RXQ
On Tue, 02 Sep 2008
In my previous posting I referenced to a couple of plots I made of the
Line output using a wideband RF noise source
I put the 2 plots on my blog here
http://ei6iz.com/?p=22
73
Brendan EI6IZ
--
Don‘t complain. Nobody will understand. Or care. And certainly don‘t try
to fix the situation
While I appreciate all the deep comments about K3 audio, I do need to report
that transformers are an effective way to eliminate hum in a less-than-ideal
installation. I have used cheap Radio Shack audio transformers for years to
allow my transceivers of all stripes to operate on PSK31 and
Hi Everyone,
I'm re doing the thread as this time I have some concrete findings to
share with you and wail be writing to Elecraft about this problem.
My previous thread was about ringing in the audio but now it is
harmonic distortion at three times the frequency.
I went around M0GJH's
I will also try two simultaneous signals and see if I can duplicate your
mixing observations.
Jack K8ZOA
Berni G0IDA wrote:
Hi Everyone,
I'm re doing the thread as this time I have some concrete findings to
share with you and wail be writing to Elecraft about this problem.
My previous
On Mon, 01 Sep 2008 14:30:45 +0100, Berni G0IDA wrote:
I hope there is a cure for this as it's frustrating listening to CW with
this sort of distortion.
There are three things you should do.
1) Make sure that the AGC is on, and that the CONFIG AGC settings are at the
defaults.
2) Reduce
output but I'm told that this
is a separate amplifier.
Steve Ellington
[EMAIL PROTECTED]
- Original Message -
From: Jim Brown [EMAIL PROTECTED]
To: elecraft@mailman.qth.net
Sent: Monday, September 01, 2008 12:05 PM
Subject: Re: [Elecraft] K3 Harmonic Distortion
On Mon, 01 Sep 2008 14
PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Jim Brown
Sent: Monday, September 01, 2008 12:06 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 Harmonic Distortion
On Mon, 01 Sep 2008 14:30:45 +0100, Berni G0IDA wrote:
I hope there is a cure for this as it's frustrating listening
Sent: Monday, September 01, 2008 12:14 PM
To: Jim Brown; elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 Harmonic Distortion
Jim
None of those things helps. I can reduce my LINE OUT gain to
1 and still see
the 3rd harmonic easily on the waterfall. I've had many rigs
On Mon, 1 Sep 2008 12:38:31 -0400, Joe Subich, W4TV wrote:
Jim is entirely correct although we will disagree a bit about
the need to keep the line out as low as he suggests. My own
measurements say the harmonic distortion is insignificant as
long as the Line Out levels stay below .5V RMS.
Thanks everyone for the replies.
I just would like to put this thread back onto its tracks. The
problem is with CW (although SSB does suffer too) and the main problem
is that I can hear the 3rd harmonic which when mixed with the
fundamental makes a rough note on CW especially when tuning
I've made a number of measurements on the K3's audio output a few days
ago in CW mode and again today, this time with two close spaced signals
inside the SSB filter as well as a single tone.
Yes, there are 3rd and other odd-order harmonics and, to a lesser
degree, even order harmonics.
Berni G0IDA wrote:
I just would like to put this thread back onto its tracks. The
problem is with CW (although SSB does suffer too) and the main problem
is that I can hear the 3rd harmonic which when mixed with the
fundamental makes a rough note on CW especially when tuning away going
up
I think it was me who used the term ghost signals when referring to the
harmonically related CW traces I could see on the CW Skimmer display. I
probably would have been completely unaware of it if I had never tried this
program. It was only obvious as I was listening to CW with a narrow filter
- typically around -60 dBu.
73,
... Joe, W4TV
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Jim Brown
Sent: Monday, September 01, 2008 1:33 PM
To: elecraft@mailman.qth.net
Subject: RE: [Elecraft] K3 Harmonic Distortion
On Mon, 1 Sep
] On Behalf Of Berni G0IDA
Sent: Monday, September 01, 2008 3:20 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3 Harmonic Distortion
Thanks everyone for the replies.
I just would like to put this thread back onto its tracks. The
problem is with CW (although SSB does suffer
I've found that the LIN OUT port has typical third harmonic levels
around -45 dB from the fundamental, with the LIN OUT level set at 10,
the factory default. The headphone port, under the same conditions, will
show the third harmonic down about 70 dB or so at levels appropriate for
my Sony
around -60 dBu.
73,
... Joe, W4TV
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Jim Brown
Sent: Monday, September 01, 2008 1:33 PM
To: elecraft@mailman.qth.net
Subject: RE: [Elecraft] K3 Harmonic Distortion
On Mon, 1 Sep 2008 12:38:31
Julian, G4ILO wrote:
I think it was me who used the term ghost signals when referring to the
harmonically related CW traces I could see on the CW Skimmer display.
Julian,
About 6 months ago I found a similar situation with another radio and
another program. In that case the distortion was
On Mon, 01 Sep 2008 18:45:36 -0400, Jack Smith wrote:
I've found that the LIN OUT port has typical third harmonic levels
around -45 dB from the fundamental, with the LIN OUT level set at 10,
the factory default. The headphone port, under the same conditions,
will
show the third harmonic down
Subject: Re: [Elecraft] K3 Harmonic Distortion
Yes indeed it would be a sorry situation if an operator can't
tell the difference between a desired signal and an audio
harmonic, fortunately
my thread is not about that.
Anyway, the noise/distortion is still there coming out
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