in-band-IMD test

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in-band-IMD test

Alexander Ponomarenko-5
GA for all K3 users.
So many guys has talks about perfect audio sound of K3.
So many talks about "analog K3 sound" on e-ham.
But how it possible if K3 have the so bad in-band IMD?
You can read about "in-band-IMD-measurements" in russian here:
http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&start=0
Or you can simply look on the pictures, where is in-band IMD-measurements of
SDR-5000, IC-7800, IC-756pro2 and K3 - so bad for HI-FI sound announced
by many K3-users:
it's for S9-level http://forum.cqham.ru/download.php?id=31966
and it's for S9+50 level http://forum.cqham.ru/download.php?id=32004
and even measurements of S/S+N-rate is poor:
http://forum.cqham.ru/download.php?id=32003

Alex de UR5LAM
RU-QRP-C#103
K3/100F #0568
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Re: in-band-IMD test

Jack Smith-6
Alex:

This is an issue with the isolation transformers in the LINE OUT ports.
I've measured similar levels, and shown how they might be reduced.
http://www.cliftonlaboratories.com/elecraft_k3_receive_audio.htm

You will not see  the same degree of distortion on the headphone output
port.

Jack K8ZOA


Alexander Ponomarenko wrote:

> GA for all K3 users.
> So many guys has talks about perfect audio sound of K3.
> So many talks about "analog K3 sound" on e-ham.
> But how it possible if K3 have the so bad in-band IMD?
> You can read about "in-band-IMD-measurements" in russian here:
> http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&start=0 
>
> Or you can simply look on the pictures, where is in-band
> IMD-measurements of
> SDR-5000, IC-7800, IC-756pro2 and K3 - so bad for HI-FI sound
> announced by many K3-users:
> it's for S9-level http://forum.cqham.ru/download.php?id=31966
> and it's for S9+50 level http://forum.cqham.ru/download.php?id=32004
> and even measurements of S/S+N-rate is poor:
> http://forum.cqham.ru/download.php?id=32003
>
> Alex de UR5LAM
> RU-QRP-C#103
> K3/100F #0568
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
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>
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Re: in-band-IMD test

Jim Brown-10
On Wed, 12 Nov 2008 16:24:27 -0500, Jack Smith wrote:

>This is an issue with the isolation transformers in the LINE OUT ports.
>I've measured similar levels, and shown how they might be reduced.

>You will not see  the same degree of distortion on the headphone output
>port.

Agreed on both counts. The Line Out is poorly designed, and that's the
problem. You'll find corresponding data on my website, measured using an
entirely different procedure.

http://audiosystemsgroup.com/K3FilterStudy.pdf

and http://audiosystemsgroup.com/FilterTestNotes.pdf

73.

Jim Brown K9YC




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Re: in-band-IMD test

Alexander Ponomarenko-5
In reply to this post by Jack Smith-6
Jack,

all these measurements, for all radios has been via PHONE-OUT.
There is two-tone measurements, but you can see these IMD even with XG1
set to s9-level.
Here is my K3 with s9-signal from XG1:
- ATT On http://forum.cqham.ru/download.php?id=32030
- ATT/PRE Off http://forum.cqham.ru/download.php?id=32031
- PRE On (it's terrible)  http://forum.cqham.ru/download.php?id=32032

P.S. Yes, I visited clifton-web, line-out has same distortion as
phone-out. :-(

Alex de UR5LAM

Jack Smith wrote:
Alex:

This is an issue with the isolation transformers in the LINE OUT ports.
I've measured similar levels, and shown how they might be reduced.
http://www.cliftonlaboratories.com/elecraft_k3_receive_audio.htm

You will not see  the same degree of distortion on the headphone output
port.

Jack K8ZOA


Alexander Ponomarenko wrote:
GA for all K3 users.
So many guys has talks about perfect audio sound of K3.
So many talks about "analog K3 sound" on e-ham.
But how it possible if K3 have the so bad in-band IMD?
You can read about "in-band-IMD-measurements" in russian here:
http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&start=0 

Or you can simply look on the pictures, where is in-band
IMD-measurements of
SDR-5000, IC-7800, IC-756pro2 and K3 - so bad for HI-FI sound announced
by many K3-users:
it's for S9-level http://forum.cqham.ru/download.php?id=31966
and it's for S9+50 level http://forum.cqham.ru/download.php?id=32004
and even measurements of S/S+N-rate is poor:
http://forum.cqham.ru/download.php?id=32003

Alex de UR5LAM
RU-QRP-C#103
K3/100F #0568
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RE: in-band-IMD test

Joe Subich, W4TV-3
In reply to this post by Jack Smith-6


> This is an issue with the isolation transformers in the LINE
> OUT ports.  I've measured similar levels, and shown how they
> might be reduced.
> http://www.cliftonlaboratories.com/elecraft_k3_receive_audio.htm

Elecraft have changed the series resistors from 604 to 50 Ohms
in current production.  See the October schematic updates on
their web site.

I'm assuming a change in the schematics indicates the modification
is now "approved."


73,

   ... Joe, W4TV
 


> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Jack Smith
> Sent: Wednesday, November 12, 2008 4:24 PM
> To: Alexander Ponomarenko; 'Elecraft'
> Subject: Re: [Elecraft] [K3] in-band-IMD test
>
>
> Alex:
>
> This is an issue with the isolation transformers in the LINE
> OUT ports.
> I've measured similar levels, and shown how they might be
> reduced.
> http://www.cliftonlaboratories.com/elecraft_k3_receive_audio.htm
>
> You will not see  the same degree of distortion on the
> headphone output
> port.
>
> Jack K8ZOA
>
>
> Alexander Ponomarenko wrote:
> > GA for all K3 users.
> > So many guys has talks about perfect audio sound of K3.
> > So many talks about "analog K3 sound" on e-ham.
> > But how it possible if K3 have the so bad in-band IMD?
> > You can read about "in-band-IMD-measurements" in russian here:
> >
> http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&
> > start=0
> >
> > Or you can simply look on the pictures, where is in-band
> > IMD-measurements of
> > SDR-5000, IC-7800, IC-756pro2 and K3 - so bad for HI-FI sound
> > announced by many K3-users:
> > it's for S9-level http://forum.cqham.ru/download.php?id=31966
> > and it's for S9+50 level http://forum.cqham.ru/download.php?id=32004
> > and even measurements of S/S+N-rate is poor:
> > http://forum.cqham.ru/download.php?id=32003
> >
> > Alex de UR5LAM
> > RU-QRP-C#103
> > K3/100F #0568

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Re: in-band-IMD test

Barry N1EU
In reply to this post by Alexander Ponomarenko-5
Alexander Ponomarenko-5 wrote
all these measurements, for all radios has been via PHONE-OUT.
There is two-tone measurements, but you can see these IMD even with XG1
set to s9-level.
Here is my K3 with s9-signal from XG1:
- ATT On http://forum.cqham.ru/download.php?id=32030
- ATT/PRE Off http://forum.cqham.ru/download.php?id=32031
- PRE On (it's terrible)  http://forum.cqham.ru/download.php?id=32032
Please take two consecutive spectrum readings with PRE On, AGC Off from the headphone jack - take one with S9 signal from XG1 and take the second with the XG1 generator turned off (i.e., with no signal in the passband).  Please post these two spectra.

I suspect many of the spikes in your spectrum reading are not related to the received signal.

Thanks,
Barry N1EU
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Re: in-band-IMD test

Alexander Ponomarenko-5


2008/11/13 Barry N1EU <[hidden email]>


Alexander Ponomarenko-5 wrote:
>
> all these measurements, for all radios has been via PHONE-OUT.
> There is two-tone measurements, but you can see these IMD even with XG1
> set to s9-level.
> Here is my K3 with s9-signal from XG1:
> - ATT On http://forum.cqham.ru/download.php?id=32030
> - ATT/PRE Off http://forum.cqham.ru/download.php?id=32031
> - PRE On (it's terrible)  http://forum.cqham.ru/download.php?id=32032
>

Please take two consecutive spectrum readings with PRE On, AGC Off from the
headphone jack - take one with S9 signal from XG1 and take the second with
the XG1 generator turned off (i.e., with no signal in the passband).  Please
post these two spectra.

I suspect many of the spikes in your spectrum reading are not related to the
received signal.

Thanks,
Barry N1EU

 
 
Barry,
 
S9 with Pre On, AGC Off you can see in my previous message.
Here is plot without XG1-tone-signal (here is from line-out, but via PHONES it's equal, yes, tomorrow you will see both plots for PHONES-out):
 
 
Guys, do you remember as we has built ours K2's?
Do you remember the Spectrogram-soft? Try use it and you will see these plots.
 
Alex de UR5LAM

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Re: in-band-IMD test

Barry N1EU
Alexander Ponomarenko-5 wrote
S9 with Pre On, AGC Off you can see in my previous message.
Here is plot without XG1-tone-signal (here is from line-out, but via PHONES
it's equal, yes, tomorrow you will see both plots for PHONES-out):
I'll wait for consecutive PHONES-out plots run tomorrow Alex - exact same levels, etc - taken with XG1 on and XG1 off.

FYI, I use SpectraLab here as well.

Thanks & 73,
Barry N1EU
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Re: in-band-IMD test

Mike Harris-9
In reply to this post by Joe Subich, W4TV-3
G'day,

I see there is a mod kit $10 but no details available on the "K3
enhancements and application notes" page on the web site.

The manual would be interesting.

Regards,

Mike VP8NO

----- Original Message -----
From: "Joe Subich, W4TV" <[hidden email]>
To: "'Jack Smith'" <[hidden email]>;
<[hidden email]>
Sent: Wednesday, November 12, 2008 7:37 PM
Subject: RE: [Elecraft] [K3] in-band-IMD test


|
|
| > This is an issue with the isolation transformers in the LINE
| > OUT ports.  I've measured similar levels, and shown how they
| > might be reduced.
| > http://www.cliftonlaboratories.com/elecraft_k3_receive_audio.htm
|
| Elecraft have changed the series resistors from 604 to 50 Ohms
| in current production.  See the October schematic updates on
| their web site.
|
| I'm assuming a change in the schematics indicates the modification
| is now "approved."
|
|
| 73,
|
|   ... Joe, W4TV

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RE: in-band-IMD test

Bill Maddock-2
In reply to this post by Joe Subich, W4TV-3
Anyone know at S/N # the new K3's started being changed to new
resistor?

Thanks and 73,

Bill  N4ZI


--- On Wed, 11/12/08, Joe Subich, W4TV <[hidden email]> wrote:

> From: Joe Subich, W4TV <[hidden email]>
> Subject: RE: [Elecraft] [K3] in-band-IMD test
> To: "'Jack Smith'" <[hidden email]>, [hidden email]
> Date: Wednesday, November 12, 2008, 4:37 PM
> > This is an issue with the isolation transformers in the
> LINE
> > OUT ports.  I've measured similar levels, and
> shown how they
> > might be reduced.
> >
> http://www.cliftonlaboratories.com/elecraft_k3_receive_audio.htm
>
> Elecraft have changed the series resistors from 604 to 50
> Ohms
> in current production.  See the October schematic updates
> on
> their web site.
>
> I'm assuming a change in the schematics indicates the
> modification
> is now "approved."
>
>
> 73,
>
>    ... Joe, W4TV
>  
>
>
> > -----Original Message-----
> > From: [hidden email]
> > [mailto:[hidden email]] On Behalf Of
> Jack Smith
> > Sent: Wednesday, November 12, 2008 4:24 PM
> > To: Alexander Ponomarenko; 'Elecraft'
> > Subject: Re: [Elecraft] [K3] in-band-IMD test
> >
> >
> > Alex:
> >
> > This is an issue with the isolation transformers in
> the LINE
> > OUT ports.
> > I've measured similar levels, and shown how they
> might be
> > reduced.
> >
> http://www.cliftonlaboratories.com/elecraft_k3_receive_audio.htm
> >
> > You will not see  the same degree of distortion on the
>
> > headphone output
> > port.
> >
> > Jack K8ZOA
> >
> >
> > Alexander Ponomarenko wrote:
> > > GA for all K3 users.
> > > So many guys has talks about perfect audio sound
> of K3.
> > > So many talks about "analog K3 sound"
> on e-ham.
> > > But how it possible if K3 have the so bad in-band
> IMD?
> > > You can read about
> "in-band-IMD-measurements" in russian here:
> > >
> >
> http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&
> > > start=0
> > >
> > > Or you can simply look on the pictures, where is
> in-band
> > > IMD-measurements of
> > > SDR-5000, IC-7800, IC-756pro2 and K3 - so bad for
> HI-FI sound
> > > announced by many K3-users:
> > > it's for S9-level
> http://forum.cqham.ru/download.php?id=31966
> > > and it's for S9+50 level
> http://forum.cqham.ru/download.php?id=32004
> > > and even measurements of S/S+N-rate is poor:
> > > http://forum.cqham.ru/download.php?id=32003
> > >
> > > Alex de UR5LAM
> > > RU-QRP-C#103
> > > K3/100F #0568
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
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>
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> Elecraft web page: http://www.elecraft.com


     
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Re: in-band-IMD test

Dean Straw
In reply to this post by Alexander Ponomarenko-5
Alexander:

Sorry but I don't read Russian. What were the K3's AGC settings for the IMD measurements? At a large input signal (S9+50 dB), using a "Fast" AGC time constant will often result in poor IMD for conventional receivers using analog type of AGC systems. I don't know the details of the K3's AGC system, however.

Have you tried the S9+50 dB input signal with the "Slow" AGC setting?

73, Dean Straw, N6BV


<quote author="Alexander Ponomarenko-5">
GA for all K3 users.
So many guys has talks about perfect audio sound of K3.
So many talks about "analog K3 sound" on e-ham.
But how it possible if K3 have the so bad in-band IMD?
You can read about "in-band-IMD-measurements" in russian here:
http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&start=0
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Re: in-band-IMD test

Alexander Ponomarenko-5
In reply to this post by Alexander Ponomarenko-5
Barry,
yes PHONES-OUT on front panel(!!!) is different from rear panel PHONES
or LINE OUT outs.

The plots from front-panel phones-out is better, but IMD spikes are present.

plot withoot S9 signal: http://forum.cqham.ru/download.php?id=32055
S9   PRE On    AGC Off: http://forum.cqham.ru/download.php?id=32057
S9   PRE On    AGC SLOW: http://forum.cqham.ru/download.php?id=32056

Alex de UR5LAM

Alex Ponomarenko wrote:

> 2008/11/13 Barry N1EU <[hidden email]
> <mailto:[hidden email]>>
>
>
>     Alexander Ponomarenko-5 wrote:
>     >
>     > all these measurements, for all radios has been via PHONE-OUT.
>     > There is two-tone measurements, but you can see these IMD even
>     with XG1
>     > set to s9-level.
>     > Here is my K3 with s9-signal from XG1:
>     > - ATT On http://forum.cqham.ru/download.php?id=32030
>     > - ATT/PRE Off http://forum.cqham.ru/download.php?id=32031
>     > - PRE On (it's terrible)
>      http://forum.cqham.ru/download.php?id=32032
>     >
>
>     Please take two consecutive spectrum readings with PRE On, AGC Off
>     from the
>     headphone jack - take one with S9 signal from XG1 and take the
>     second with
>     the XG1 generator turned off (i.e., with no signal in the
>     passband).  Please
>     post these two spectra.
>
>     I suspect many of the spikes in your spectrum reading are not
>     related to the
>     received signal.
>
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RE: in-band-IMD test

Arie Kleingeld PA3A-2
Alex,

Good job!

73
Arie PA3A

-----Oorspronkelijk bericht-----
Van: [hidden email]
[mailto:[hidden email]] Namens Alexander Ponomarenko
Verzonden: donderdag 13 november 2008 9:49
CC: [hidden email]
Onderwerp: Re: [K3] [Elecraft] in-band-IMD test


Barry,
yes PHONES-OUT on front panel(!!!) is different from rear panel PHONES
or LINE OUT outs.

The plots from front-panel phones-out is better, but IMD spikes are
present.

plot withoot S9 signal: http://forum.cqham.ru/download.php?id=32055
S9   PRE On    AGC Off: http://forum.cqham.ru/download.php?id=32057
S9   PRE On    AGC SLOW: http://forum.cqham.ru/download.php?id=32056

Alex de UR5LAM


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Re: in-band-IMD test

E72X
In reply to this post by Dean Straw

The Audio mod is a very simply! You just need to add simple two resistor pararell on KIO3 module and replace one RFI choke! If anyone need mode just send me mail and I will forward pdf direct !

73, E72X,


<quote author="Dean Straw">
Alexander:

Sorry but I don't read Russian. What were the K3's AGC settings for the IMD measurements? At a large input signal (S9+50 dB), using a "Fast" AGC time constant will often result in poor IMD for conventional receivers using analog type of AGC systems. I don't know the details of the K3's AGC system, however.

Have you tried the S9+50 dB input signal with the "Slow" AGC setting?

73, Dean Straw, N6BV


Alexander Ponomarenko-5 wrote
GA for all K3 users.
So many guys has talks about perfect audio sound of K3.
So many talks about "analog K3 sound" on e-ham.
But how it possible if K3 have the so bad in-band IMD?
You can read about "in-band-IMD-measurements" in russian here:
http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&start=0
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Re: in-band-IMD test

E72X
In reply to this post by Dean Straw

The Audio mod is a very simply! You just need to add simple two resistor pararell on KIO3 module and replace one RFI choke! If anyone need mode just send me mail and I will forward pdf direct !

73, E72X,


<quote author="Dean Straw">
Alexander:

Sorry but I don't read Russian. What were the K3's AGC settings for the IMD measurements? At a large input signal (S9+50 dB), using a "Fast" AGC time constant will often result in poor IMD for conventional receivers using analog type of AGC systems. I don't know the details of the K3's AGC system, however.

Have you tried the S9+50 dB input signal with the "Slow" AGC setting?

73, Dean Straw, N6BV


Alexander Ponomarenko-5 wrote
GA for all K3 users.
So many guys has talks about perfect audio sound of K3.
So many talks about "analog K3 sound" on e-ham.
But how it possible if K3 have the so bad in-band IMD?
You can read about "in-band-IMD-measurements" in russian here:
http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&start=0
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|

Re: in-band-IMD test

E72X
In reply to this post by Dean Straw

The Audio mod is a very simply! You just need to add simple two resistor pararell on KIO3 module and replace one RFI choke! If anyone need mode just send me mail and I will forward pdf direct !

73, E72X,


<quote author="Dean Straw">
Alexander:

Sorry but I don't read Russian. What were the K3's AGC settings for the IMD measurements? At a large input signal (S9+50 dB), using a "Fast" AGC time constant will often result in poor IMD for conventional receivers using analog type of AGC systems. I don't know the details of the K3's AGC system, however.

Have you tried the S9+50 dB input signal with the "Slow" AGC setting?

73, Dean Straw, N6BV


Alexander Ponomarenko-5 wrote
GA for all K3 users.
So many guys has talks about perfect audio sound of K3.
So many talks about "analog K3 sound" on e-ham.
But how it possible if K3 have the so bad in-band IMD?
You can read about "in-band-IMD-measurements" in russian here:
http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&start=0
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Re: in-band-IMD test

E72X
In reply to this post by Dean Straw

The Audio mod is a very simply! You just need to add simple two resistor pararell on KIO3 module and replace one RFI choke! If anyone need mode just send me mail and I will forward pdf direct !

73, E72X,


<quote author="Dean Straw">
Alexander:

Sorry but I don't read Russian. What were the K3's AGC settings for the IMD measurements? At a large input signal (S9+50 dB), using a "Fast" AGC time constant will often result in poor IMD for conventional receivers using analog type of AGC systems. I don't know the details of the K3's AGC system, however.

Have you tried the S9+50 dB input signal with the "Slow" AGC setting?

73, Dean Straw, N6BV


Alexander Ponomarenko-5 wrote
GA for all K3 users.
So many guys has talks about perfect audio sound of K3.
So many talks about "analog K3 sound" on e-ham.
But how it possible if K3 have the so bad in-band IMD?
You can read about "in-band-IMD-measurements" in russian here:
http://forum.cqham.ru/viewtopic.php?t=17119&postdays=0&postorder=asc&&start=0
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Re: in-band-IMD test

dj7mgq
In reply to this post by E72X
Hallo,

> The Audio mod is a very simply! You just need to add simple two resistor
> pararell on KIO3 module and replace one RFI choke! If anyone need mode just
> send me mail and I will forward pdf direct !

Has this modification been blessed by Elecraft or is it an unofficial mod?

Is the PDF an official doc by Elecraft?

vy 73 de toby

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Re: in-band-IMD test

Barry N1EU
In reply to this post by Alexander Ponomarenko-5
Alexander Ponomarenko-5 wrote
yes PHONES-OUT on front panel(!!!) is different from rear panel PHONES
or LINE OUT outs.

The plots from front-panel phones-out is better, but IMD spikes are present.

plot withoot S9 signal: http://forum.cqham.ru/download.php?id=32055
S9   PRE On    AGC Off: http://forum.cqham.ru/download.php?id=32057
S9   PRE On    AGC SLOW: http://forum.cqham.ru/download.php?id=32056
Thanks for running the test again Alex!

First off, is this really IMD we're looking at?  Aren't you injecting a single signal?  Isn't this harmonic distortion, not IMD?

Looking at the s9 agc off pre on plot, the worst "distortion" product is still >60dB down.  It would be nice if we saw zero distortion products, but I suspect that the distortion seen here is completely inaudible.

73,
Barry N1EU
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Re: in-band-IMD test

Alexander Ponomarenko-5
Barry N1EU wrote:

> Alexander Ponomarenko-5 wrote:
>  
>> yes PHONES-OUT on front panel(!!!) is different from rear panel PHONES
>> or LINE OUT outs.
>>
>> The plots from front-panel phones-out is better, but IMD spikes are
>> present.
>>
>> plot withoot S9 signal: http://forum.cqham.ru/download.php?id=32055
>> S9   PRE On    AGC Off: http://forum.cqham.ru/download.php?id=32057
>> S9   PRE On    AGC SLOW: http://forum.cqham.ru/download.php?id=32056
> Thanks for running the test again Alex!
>
> First off, is this really IMD we're looking at?  Aren't you injecting a
> single signal?  Isn't this harmonic distortion, not IMD?
>
> Looking at the s9 agc off pre on plot, the worst "distortion" product is
> still >60dB down.  It would be nice if we saw zero distortion products, but
> I suspect that the distortion seen here is completely inaudible.
>
> 73,
> Barry N1EU
>  
Barry,

now I have only one-tone generator XG1 with S3 and S9 level.
But in my first message you can to see TWO-TONE in-band IMD
results for ic7800, ic756pro2, Flex-5k and K3 for S9 and S9+50 levels.
For all these Radios was used same measure-method on one table.
And of course AF-out for all it was from PHONES-out on FP.

s9+50 AGC-Fast PRE-On http://forum.cqham.ru/download.php?id=32004
s9 AGC-Fast PRE-On http://forum.cqham.ru/download.php?id=32004

These results from Alex UR0ID. The FireBox sound-card are no been
overloaded.
But hope I get two-tone generator from Alex, and also check my K3 for
two-tone IMD.

Alex de UR5LAM



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