Sherwood Engineering Tests

classic Classic list List threaded Threaded
30 messages Options
12
Reply | Threaded
Open this post in threaded view
|

Sherwood Engineering Tests

Locherbob
The Sherwood ratings on receivers has just been updated to show the K3
with the new synthesizer. See: http://www.sherweng.com/table.html

Looking good - congratulations to Wayne and Eric!

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Jim Bolit

Guys,

Further, pesky, facts on said Real Radio at
http://www.sherweng.com/table.html .

Number two on the list.  That is out of 116 receivers listed on the Sherwood
page.  

That puts said Real Radio in the top 3% of the radios Bob Sherwood has
tested for a critical receiver performance parameter.

BTW, you will have to use the "Page Down" button, more than twice, to even
get a hint of the Kenwood 590.  It is number 20 on the list, putting it in
the top 17%

Also, important to note, is the Drake R4-C with the Sherwood roofing mod,
listed at number 28.  The R4-C is *ONLY*
45 (forty five) year old technology and that puts it in the top 23%.  Yep,
FORTY FIVE year old technology.  Yep, top 23 %.

Just some further, pesky, facts.........................

Rake

P.S.  BTW, I learned 45 years ago.  This flies in the face of someone's
comment that I never learn.

Ho Hum, another pesky fact.............





-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Bob
Locher
Sent: Monday, February 23, 2015 8:23 PM
To: [hidden email]
Subject: [Elecraft] Sherwood Engineering Tests

The Sherwood ratings on receivers has just been updated to show the K3 with
the new synthesizer. See: http://www.sherweng.com/table.html

Looking good - congratulations to Wayne and Eric!

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message
delivered to [hidden email]
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Wes (N7WS)
I'm sure there's a point here and I just fail to see what it is.

Rob has stated many times (look for his videos) that one number does not a radio
make.  In fact, as best that I know, he doesn't own a K3.

Wes  N7WS

On 2/23/2015 11:01 PM, jim wrote:

> Guys,
>
> Further, pesky, facts on said Real Radio at
> http://www.sherweng.com/table.html .
>
> Number two on the list.  That is out of 116 receivers listed on the Sherwood
> page.
>
> That puts said Real Radio in the top 3% of the radios Bob Sherwood has
> tested for a critical receiver performance parameter.
>
> BTW, you will have to use the "Page Down" button, more than twice, to even
> get a hint of the Kenwood 590.  It is number 20 on the list, putting it in
> the top 17%
>
> Also, important to note, is the Drake R4-C with the Sherwood roofing mod,
> listed at number 28.  The R4-C is *ONLY*
> 45 (forty five) year old technology and that puts it in the top 23%.  Yep,
> FORTY FIVE year old technology.  Yep, top 23 %.
>
> Just some further, pesky, facts.........................
>
> Rake
>
> P.S.  BTW, I learned 45 years ago.  This flies in the face of someone's
> comment that I never learn.
>
> Ho Hum, another pesky fact.............
>
>
>
>
>
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Jim Bolit
Wes,

I agree, and if you look at a post I made a couple days ago, it states that.
Sherwood also states his list is sorted on one column and people shud take
all factors into account when choosing a radio.

I would NOT recommend a K3 for it's audio.  

Each person has their needs and should review them carefully.  I would also
not recommend a Drake R4-C, even though it is in the top quartile.

I will send you a copy of an earlier post that I made.


Jim
W6AIM



-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Wes
(N7WS)
Sent: Tuesday, February 24, 2015 6:12 AM
To: [hidden email]
Subject: Re: [Elecraft] Sherwood Engineering Tests

I'm sure there's a point here and I just fail to see what it is.

Rob has stated many times (look for his videos) that one number does not a
radio make.  In fact, as best that I know, he doesn't own a K3.

Wes  N7WS

On 2/23/2015 11:01 PM, jim wrote:

> Guys,
>
> Further, pesky, facts on said Real Radio at
> http://www.sherweng.com/table.html .
>
> Number two on the list.  That is out of 116 receivers listed on the
> Sherwood page.
>
> That puts said Real Radio in the top 3% of the radios Bob Sherwood has
> tested for a critical receiver performance parameter.
>
> BTW, you will have to use the "Page Down" button, more than twice, to
> even get a hint of the Kenwood 590.  It is number 20 on the list,
> putting it in the top 17%
>
> Also, important to note, is the Drake R4-C with the Sherwood roofing
> mod, listed at number 28.  The R4-C is *ONLY*
> 45 (forty five) year old technology and that puts it in the top 23%.  
> Yep, FORTY FIVE year old technology.  Yep, top 23 %.
>
> Just some further, pesky, facts.........................
>
> Rake
>
> P.S.  BTW, I learned 45 years ago.  This flies in the face of
> someone's comment that I never learn.
>
> Ho Hum, another pesky fact.............
>
>
>
>
>
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message
delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

wayne burdick
Administrator
Jim (et al),

The K3's audio has improved due to three factors in the past couple of years:

- a low-noise, low-pass audio filter stage was added to the DSP board, eliminating high-pitched CODEC artifacts

- DSP firmware changes were made to correct AGC linearity and eliminate a CODEC quantization problem

- main MCU firmware was modified to allow the user to select the lower AF cutoff in CW mode (100/200/300 Hz) by adjusting the lower edge of the crystal filters

With the above changes in place, we carefully measured the K3's audio spectra and compared it to other radios with the same type of class-AB final AF amplifier IC (most transceivers fall into this category). They are all virtually identical.

Rob, too, told us that the audio spectra he measured on a recent K3 (with new synths and the latest DSP and MCU firmware) was significantly improved from the K3 he measured several years ago.

While it is possible to reduce audio IMD products even further, this typically requires a class-A final audio output stage, which would add perhaps 0.5 to 1.0 amps of additional receive-mode current drain (and an associated heatsink). That is inconsistent with the K3's intended usage, which includes excellent power efficiency for portable applications (Field Day/DXpedition/travel). Also, most users would not notice such a subtle change.

73,
Wayne
N6KR


On Feb 24, 2015, at 8:19 AM, jim <[hidden email]> wrote:

> Wes,
>
> I agree, and if you look at a post I made a couple days ago, it states that.
> Sherwood also states his list is sorted on one column and people shud take
> all factors into account when choosing a radio.
>
> I would NOT recommend a K3 for it's audio.  
>
> Each person has their needs and should review them carefully.  I would also
> not recommend a Drake R4-C, even though it is in the top quartile.
>
> I will send you a copy of an earlier post that I made.
>
>
> Jim
> W6AIM
>
>
>
> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of Wes
> (N7WS)
> Sent: Tuesday, February 24, 2015 6:12 AM
> To: [hidden email]
> Subject: Re: [Elecraft] Sherwood Engineering Tests
>
> I'm sure there's a point here and I just fail to see what it is.
>
> Rob has stated many times (look for his videos) that one number does not a
> radio make.  In fact, as best that I know, he doesn't own a K3.
>
> Wes  N7WS
>
> On 2/23/2015 11:01 PM, jim wrote:
>> Guys,
>>
>> Further, pesky, facts on said Real Radio at
>> http://www.sherweng.com/table.html .
>>
>> Number two on the list.  That is out of 116 receivers listed on the
>> Sherwood page.
>>
>> That puts said Real Radio in the top 3% of the radios Bob Sherwood has
>> tested for a critical receiver performance parameter.
>>
>> BTW, you will have to use the "Page Down" button, more than twice, to
>> even get a hint of the Kenwood 590.  It is number 20 on the list,
>> putting it in the top 17%
>>
>> Also, important to note, is the Drake R4-C with the Sherwood roofing
>> mod, listed at number 28.  The R4-C is *ONLY*
>> 45 (forty five) year old technology and that puts it in the top 23%.  
>> Yep, FORTY FIVE year old technology.  Yep, top 23 %.
>>
>> Just some further, pesky, facts.........................
>>
>> Rake
>>
>> P.S.  BTW, I learned 45 years ago.  This flies in the face of
>> someone's comment that I never learn.
>>
>> Ho Hum, another pesky fact.............
>>
>>
>>
>>
>>
>>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html Message
> delivered to [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

George Dubovsky
On Tue, Feb 24, 2015 at 12:27 PM, Wayne Burdick <[hidden email]> wrote:

> Jim (et al),
>
> The K3's audio has improved due to three factors in the past couple of
> years:
>
> - a low-noise, low-pass audio filter stage was added to the DSP board,
> eliminating high-pitched CODEC artifacts
>

​Approximately what serial number introduced this change? Thanks.

73,

geo - n4ua​


>
> - DSP firmware changes were made to correct AGC linearity and eliminate a
> CODEC quantization problem
>
> - main MCU firmware was modified to allow the user to select the lower AF
> cutoff in CW mode (100/200/300 Hz) by adjusting the lower edge of the
> crystal filters
>
> With the above changes in place, we carefully measured the K3's audio
> spectra and compared it to other radios with the same type of class-AB
> final AF amplifier IC (most transceivers fall into this category). They are
> all virtually identical.
>
> Rob, too, told us that the audio spectra he measured on a recent K3 (with
> new synths and the latest DSP and MCU firmware) was significantly improved
> from the K3 he measured several years ago.
>
> While it is possible to reduce audio IMD products even further, this
> typically requires a class-A final audio output stage, which would add
> perhaps 0.5 to 1.0 amps of additional receive-mode current drain (and an
> associated heatsink). That is inconsistent with the K3's intended usage,
> which includes excellent power efficiency for portable applications (Field
> Day/DXpedition/travel). Also, most users would not notice such a subtle
> change.
>
> 73,
> Wayne
> N6KR
>
>
> On Feb 24, 2015, at 8:19 AM, jim <[hidden email]> wrote:
>
> > Wes,
> >
> > I agree, and if you look at a post I made a couple days ago, it states
> that.
> > Sherwood also states his list is sorted on one column and people shud
> take
> > all factors into account when choosing a radio.
> >
> > I would NOT recommend a K3 for it's audio.
> >
> > Each person has their needs and should review them carefully.  I would
> also
> > not recommend a Drake R4-C, even though it is in the top quartile.
> >
> > I will send you a copy of an earlier post that I made.
> >
> >
> > Jim
> > W6AIM
> >
> >
> >
> > -----Original Message-----
> > From: Elecraft [mailto:[hidden email]] On Behalf Of
> Wes
> > (N7WS)
> > Sent: Tuesday, February 24, 2015 6:12 AM
> > To: [hidden email]
> > Subject: Re: [Elecraft] Sherwood Engineering Tests
> >
> > I'm sure there's a point here and I just fail to see what it is.
> >
> > Rob has stated many times (look for his videos) that one number does not
> a
> > radio make.  In fact, as best that I know, he doesn't own a K3.
> >
> > Wes  N7WS
> >
> > On 2/23/2015 11:01 PM, jim wrote:
> >> Guys,
> >>
> >> Further, pesky, facts on said Real Radio at
> >> http://www.sherweng.com/table.html .
> >>
> >> Number two on the list.  That is out of 116 receivers listed on the
> >> Sherwood page.
> >>
> >> That puts said Real Radio in the top 3% of the radios Bob Sherwood has
> >> tested for a critical receiver performance parameter.
> >>
> >> BTW, you will have to use the "Page Down" button, more than twice, to
> >> even get a hint of the Kenwood 590.  It is number 20 on the list,
> >> putting it in the top 17%
> >>
> >> Also, important to note, is the Drake R4-C with the Sherwood roofing
> >> mod, listed at number 28.  The R4-C is *ONLY*
> >> 45 (forty five) year old technology and that puts it in the top 23%.
> >> Yep, FORTY FIVE year old technology.  Yep, top 23 %.
> >>
> >> Just some further, pesky, facts.........................
> >>
> >> Rake
> >>
> >> P.S.  BTW, I learned 45 years ago.  This flies in the face of
> >> someone's comment that I never learn.
> >>
> >> Ho Hum, another pesky fact.............
> >>
> >>
> >>
> >>
> >>
> >>
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> Message
> > delivered to [hidden email]
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> > Message delivered to [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

wayne burdick
Administrator
Hi George,

I just checked the web site and I see that we've been shipping K3s with the new DSP board since sometime in 2010. (Confirming that time flies.)

You can upgrade the DSP board from rev. C to rev. D for $109 (K3DSPUPGD); this includes both the audio low-pass filter and a bit of an improvement in LF audio response. Or you can add just the audio filter section as a small daughter board for $39 (K3DSPLPF).

The upgrade does improve the spectra as viewed on an audio spectrum analyzer, but many operators won't be able to hear the effects by ear. Those who can hear them have told us it was a major improvement.

Wayne
N6KR



On Feb 24, 2015, at 9:40 AM, George Dubovsky <[hidden email]> wrote:

>
>
> On Tue, Feb 24, 2015 at 12:27 PM, Wayne Burdick <[hidden email]> wrote:
> Jim (et al),
>
> The K3's audio has improved due to three factors in the past couple of years:
>
> - a low-noise, low-pass audio filter stage was added to the DSP board, eliminating high-pitched CODEC artifacts
>
> ​Approximately what serial number introduced this change? Thanks.
>
> 73,
>
> geo - n4ua​
>
> - DSP firmware changes were made to correct AGC linearity and eliminate a CODEC quantization problem
>
> - main MCU firmware was modified to allow the user to select the lower AF cutoff in CW mode (100/200/300 Hz) by adjusting the lower edge of the crystal filters
>
> With the above changes in place, we carefully measured the K3's audio spectra and compared it to other radios with the same type of class-AB final AF amplifier IC (most transceivers fall into this category). They are all virtually identical.
>
> Rob, too, told us that the audio spectra he measured on a recent K3 (with new synths and the latest DSP and MCU firmware) was significantly improved from the K3 he measured several years ago.
>
> While it is possible to reduce audio IMD products even further, this typically requires a class-A final audio output stage, which would add perhaps 0.5 to 1.0 amps of additional receive-mode current drain (and an associated heatsink). That is inconsistent with the K3's intended usage, which includes excellent power efficiency for portable applications (Field Day/DXpedition/travel). Also, most users would not notice such a subtle change.
>
> 73,
> Wayne
> N6KR
>
>
> On Feb 24, 2015, at 8:19 AM, jim <[hidden email]> wrote:
>
> > Wes,
> >
> > I agree, and if you look at a post I made a couple days ago, it states that.
> > Sherwood also states his list is sorted on one column and people shud take
> > all factors into account when choosing a radio.
> >
> > I would NOT recommend a K3 for it's audio.
> >
> > Each person has their needs and should review them carefully.  I would also
> > not recommend a Drake R4-C, even though it is in the top quartile.
> >
> > I will send you a copy of an earlier post that I made.
> >
> >
> > Jim
> > W6AIM
> >
> >
> >
> > -----Original Message-----
> > From: Elecraft [mailto:[hidden email]] On Behalf Of Wes
> > (N7WS)
> > Sent: Tuesday, February 24, 2015 6:12 AM
> > To: [hidden email]
> > Subject: Re: [Elecraft] Sherwood Engineering Tests
> >
> > I'm sure there's a point here and I just fail to see what it is.
> >
> > Rob has stated many times (look for his videos) that one number does not a
> > radio make.  In fact, as best that I know, he doesn't own a K3.
> >
> > Wes  N7WS
> >
> > On 2/23/2015 11:01 PM, jim wrote:
> >> Guys,
> >>
> >> Further, pesky, facts on said Real Radio at
> >> http://www.sherweng.com/table.html .
> >>
> >> Number two on the list.  That is out of 116 receivers listed on the
> >> Sherwood page.
> >>
> >> That puts said Real Radio in the top 3% of the radios Bob Sherwood has
> >> tested for a critical receiver performance parameter.
> >>
> >> BTW, you will have to use the "Page Down" button, more than twice, to
> >> even get a hint of the Kenwood 590.  It is number 20 on the list,
> >> putting it in the top 17%
> >>
> >> Also, important to note, is the Drake R4-C with the Sherwood roofing
> >> mod, listed at number 28.  The R4-C is *ONLY*
> >> 45 (forty five) year old technology and that puts it in the top 23%.
> >> Yep, FORTY FIVE year old technology.  Yep, top 23 %.
> >>
> >> Just some further, pesky, facts.........................
> >>
> >> Rake
> >>
> >> P.S.  BTW, I learned 45 years ago.  This flies in the face of
> >> someone's comment that I never learn.
> >>
> >> Ho Hum, another pesky fact.............
> >>
> >>
> >>
> >>
> >>
> >>
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html Message
> > delivered to [hidden email]
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> > Message delivered to [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Yngvi (TF3Y)
These are interesting stats.

One thing I noticed was the apparent loss in sensitivity as measured by
Sherwood. This is probably not a big issue for most these days with the
ever increasing noise levels but for the few in silent locations, incl.
some DXpeditions this might be an issue.

Any comments on this?

73, Yngvi TF3Y
http://www.tf3y.net

On Tue, Feb 24, 2015 at 5:48 PM, Wayne Burdick <[hidden email]> wrote:

> Hi George,
>
> I just checked the web site and I see that we've been shipping K3s with
> the new DSP board since sometime in 2010. (Confirming that time flies.)
>
> You can upgrade the DSP board from rev. C to rev. D for $109 (K3DSPUPGD);
> this includes both the audio low-pass filter and a bit of an improvement in
> LF audio response. Or you can add just the audio filter section as a small
> daughter board for $39 (K3DSPLPF).
>
> The upgrade does improve the spectra as viewed on an audio spectrum
> analyzer, but many operators won't be able to hear the effects by ear.
> Those who can hear them have told us it was a major improvement.
>
> Wayne
> N6KR
>
>
>
> On Feb 24, 2015, at 9:40 AM, George Dubovsky <[hidden email]> wrote:
>
> >
> >
> > On Tue, Feb 24, 2015 at 12:27 PM, Wayne Burdick <[hidden email]>
> wrote:
> > Jim (et al),
> >
> > The K3's audio has improved due to three factors in the past couple of
> years:
> >
> > - a low-noise, low-pass audio filter stage was added to the DSP board,
> eliminating high-pitched CODEC artifacts
> >
> > Approximately what serial number introduced this change? Thanks.
> >
> > 73,
> >
> > geo - n4ua
> >
> > - DSP firmware changes were made to correct AGC linearity and eliminate
> a CODEC quantization problem
> >
> > - main MCU firmware was modified to allow the user to select the lower
> AF cutoff in CW mode (100/200/300 Hz) by adjusting the lower edge of the
> crystal filters
> >
> > With the above changes in place, we carefully measured the K3's audio
> spectra and compared it to other radios with the same type of class-AB
> final AF amplifier IC (most transceivers fall into this category). They are
> all virtually identical.
> >
> > Rob, too, told us that the audio spectra he measured on a recent K3
> (with new synths and the latest DSP and MCU firmware) was significantly
> improved from the K3 he measured several years ago.
> >
> > While it is possible to reduce audio IMD products even further, this
> typically requires a class-A final audio output stage, which would add
> perhaps 0.5 to 1.0 amps of additional receive-mode current drain (and an
> associated heatsink). That is inconsistent with the K3's intended usage,
> which includes excellent power efficiency for portable applications (Field
> Day/DXpedition/travel). Also, most users would not notice such a subtle
> change.
> >
> > 73,
> > Wayne
> > N6KR
> >
> >
> > On Feb 24, 2015, at 8:19 AM, jim <[hidden email]> wrote:
> >
> > > Wes,
> > >
> > > I agree, and if you look at a post I made a couple days ago, it states
> that.
> > > Sherwood also states his list is sorted on one column and people shud
> take
> > > all factors into account when choosing a radio.
> > >
> > > I would NOT recommend a K3 for it's audio.
> > >
> > > Each person has their needs and should review them carefully.  I would
> also
> > > not recommend a Drake R4-C, even though it is in the top quartile.
> > >
> > > I will send you a copy of an earlier post that I made.
> > >
> > >
> > > Jim
> > > W6AIM
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Elecraft [mailto:[hidden email]] On Behalf Of
> Wes
> > > (N7WS)
> > > Sent: Tuesday, February 24, 2015 6:12 AM
> > > To: [hidden email]
> > > Subject: Re: [Elecraft] Sherwood Engineering Tests
> > >
> > > I'm sure there's a point here and I just fail to see what it is.
> > >
> > > Rob has stated many times (look for his videos) that one number does
> not a
> > > radio make.  In fact, as best that I know, he doesn't own a K3.
> > >
> > > Wes  N7WS
> > >
> > > On 2/23/2015 11:01 PM, jim wrote:
> > >> Guys,
> > >>
> > >> Further, pesky, facts on said Real Radio at
> > >> http://www.sherweng.com/table.html .
> > >>
> > >> Number two on the list.  That is out of 116 receivers listed on the
> > >> Sherwood page.
> > >>
> > >> That puts said Real Radio in the top 3% of the radios Bob Sherwood has
> > >> tested for a critical receiver performance parameter.
> > >>
> > >> BTW, you will have to use the "Page Down" button, more than twice, to
> > >> even get a hint of the Kenwood 590.  It is number 20 on the list,
> > >> putting it in the top 17%
> > >>
> > >> Also, important to note, is the Drake R4-C with the Sherwood roofing
> > >> mod, listed at number 28.  The R4-C is *ONLY*
> > >> 45 (forty five) year old technology and that puts it in the top 23%.
> > >> Yep, FORTY FIVE year old technology.  Yep, top 23 %.
> > >>
> > >> Just some further, pesky, facts.........................
> > >>
> > >> Rake
> > >>
> > >> P.S.  BTW, I learned 45 years ago.  This flies in the face of
> > >> someone's comment that I never learn.
> > >>
> > >> Ho Hum, another pesky fact.............
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >
> > > ______________________________________________________________
> > > Elecraft mailing list
> > > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > > Help: http://mailman.qth.net/mmfaq.htm
> > > Post: mailto:[hidden email]
> > >
> > > This list hosted by: http://www.qsl.net
> > > Please help support this email list: http://www.qsl.net/donate.html
> Message
> > > delivered to [hidden email]
> > >
> > > ______________________________________________________________
> > > Elecraft mailing list
> > > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > > Help: http://mailman.qth.net/mmfaq.htm
> > > Post: mailto:[hidden email]
> > >
> > > This list hosted by: http://www.qsl.net
> > > Please help support this email list: http://www.qsl.net/donate.html
> > > Message delivered to [hidden email]
> >
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> > Message delivered to [hidden email]
> >
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>



--
http://www.tf3y.net
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Brendan Minish
In reply to this post by wayne burdick
I was one of the people who could most definitely hear the DSP artefacts
above 12Khz prior to the DSP low pass filter upgrade.

The low pass filter upgrade completely resolved it for me, this along
with the various other changes over the years now has the K3 sounding
very good to my ears.  

Do make sure that the speakers and headphones you are using are
reasonably efficient so that the K3 can drive them effectively without
having to run the AF amp 'flat out'  

For speakers I use a couple of old Motorola 2way radio speakers (3 Ohm
impedance I think).
As a headset I generally use a beyerdynmic DT-109 with 50Ohm earpieces,
this works wonderfully with the K3 but as I am a fairly soft talker I
made up a small preamp for the mic element
http://ei6iz.com/?p=28

 

On Tue, 2015-02-24 at 09:48 -0800, Wayne Burdick wrote:
>
...
> Or you can add just the audio filter section as a small daughter board
> for $39 (K3DSPLPF).
>
> The upgrade does improve the spectra as viewed on an audio spectrum
> analyzer, but many operators won't be able to hear the effects by ear.
> Those who can hear them have told us it was a major improvement.
>
> Wayne
> N6KR


--
73
Brendan EI6IZ

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Jim Bolit
In reply to this post by wayne burdick
Wayne,

Thanks.

My Serial Number is  04841.  I was told the LPF was "most likely" in my
radio and I have not taken it apart to see if that is the case.

DSP 1 and DSP 2 are at 02.83

MCU is at 04.86

As I stated in a mail I sent to the reflector, two days ago, I will be
sending in my K3 on RMA to have you review and update where necessary.  I
will include a request to have Elecraft look at the audio spectra to make
sure it is **clean**.

Are the new Synth's needed for better audio performance?  The **noise and
hiss* is present with no signals present in the bandwidth of the 400 Hz
crystal filter (or for that matter, any of the filters choosen).

Look forward to seeing the results of the repair/update and will post my
results.

Jim
W6AIM



-----Original Message-----
From: Wayne Burdick [mailto:[hidden email]]
Sent: Tuesday, February 24, 2015 9:28 AM
To: jim
Cc: 'Wes (N7WS)'; [hidden email]
Subject: Re: [Elecraft] Sherwood Engineering Tests

Jim (et al),

The K3's audio has improved due to three factors in the past couple of
years:

- a low-noise, low-pass audio filter stage was added to the DSP board,
eliminating high-pitched CODEC artifacts

- DSP firmware changes were made to correct AGC linearity and eliminate a
CODEC quantization problem

- main MCU firmware was modified to allow the user to select the lower AF
cutoff in CW mode (100/200/300 Hz) by adjusting the lower edge of the
crystal filters

With the above changes in place, we carefully measured the K3's audio
spectra and compared it to other radios with the same type of class-AB final
AF amplifier IC (most transceivers fall into this category). They are all
virtually identical.

Rob, too, told us that the audio spectra he measured on a recent K3 (with
new synths and the latest DSP and MCU firmware) was significantly improved
from the K3 he measured several years ago.

While it is possible to reduce audio IMD products even further, this
typically requires a class-A final audio output stage, which would add
perhaps 0.5 to 1.0 amps of additional receive-mode current drain (and an
associated heatsink). That is inconsistent with the K3's intended usage,
which includes excellent power efficiency for portable applications (Field
Day/DXpedition/travel). Also, most users would not notice such a subtle
change.

73,
Wayne
N6KR


On Feb 24, 2015, at 8:19 AM, jim <[hidden email]> wrote:

> Wes,
>
> I agree, and if you look at a post I made a couple days ago, it states
that.

> Sherwood also states his list is sorted on one column and people shud
> take all factors into account when choosing a radio.
>
> I would NOT recommend a K3 for it's audio.  
>
> Each person has their needs and should review them carefully.  I would
> also not recommend a Drake R4-C, even though it is in the top quartile.
>
> I will send you a copy of an earlier post that I made.
>
>
> Jim
> W6AIM
>
>
>
> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of
> Wes
> (N7WS)
> Sent: Tuesday, February 24, 2015 6:12 AM
> To: [hidden email]
> Subject: Re: [Elecraft] Sherwood Engineering Tests
>
> I'm sure there's a point here and I just fail to see what it is.
>
> Rob has stated many times (look for his videos) that one number does
> not a radio make.  In fact, as best that I know, he doesn't own a K3.
>
> Wes  N7WS
>
> On 2/23/2015 11:01 PM, jim wrote:
>> Guys,
>>
>> Further, pesky, facts on said Real Radio at
>> http://www.sherweng.com/table.html .
>>
>> Number two on the list.  That is out of 116 receivers listed on the
>> Sherwood page.
>>
>> That puts said Real Radio in the top 3% of the radios Bob Sherwood
>> has tested for a critical receiver performance parameter.
>>
>> BTW, you will have to use the "Page Down" button, more than twice, to
>> even get a hint of the Kenwood 590.  It is number 20 on the list,
>> putting it in the top 17%
>>
>> Also, important to note, is the Drake R4-C with the Sherwood roofing
>> mod, listed at number 28.  The R4-C is *ONLY*
>> 45 (forty five) year old technology and that puts it in the top 23%.  
>> Yep, FORTY FIVE year old technology.  Yep, top 23 %.
>>
>> Just some further, pesky, facts.........................
>>
>> Rake
>>
>> P.S.  BTW, I learned 45 years ago.  This flies in the face of
>> someone's comment that I never learn.
>>
>> Ho Hum, another pesky fact.............
>>
>>
>>
>>
>>
>>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net Please help support this email
> list: http://www.qsl.net/donate.html Message delivered to
> [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net Please help support this email
> list: http://www.qsl.net/donate.html Message delivered to
> [hidden email]


______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

wayne burdick
Administrator
Jim,

Yes, you have the new DSP boards. I'm sure customer support will check out your audio as requested.

There will always be noise and hiss with no signal present and gain controls maximized, because the K3 has a lot of gain in the RX signal path, like any modern transceiver. But with AF gain, RF gain and preamp settings appropriately adjusted, even the noise from a very poor antenna will completely dominate any noise generated within the radio itself. If not, you have something set up incorrectly, or a hardware issue that CS will be able to identify.

The new synths are not required just to produce clean audio. It should already be clean.

73,
Wayne
N6KR


On Feb 24, 2015, at 10:50 AM, jim <[hidden email]> wrote:

> Wayne,
>
> Thanks.
>
> My Serial Number is  04841.  I was told the LPF was "most likely" in my
> radio and I have not taken it apart to see if that is the case.
>
> DSP 1 and DSP 2 are at 02.83
>
> MCU is at 04.86
>
> As I stated in a mail I sent to the reflector, two days ago, I will be
> sending in my K3 on RMA to have you review and update where necessary.  I
> will include a request to have Elecraft look at the audio spectra to make
> sure it is **clean**.
>
> Are the new Synth's needed for better audio performance?  The **noise and
> hiss* is present with no signals present in the bandwidth of the 400 Hz
> crystal filter (or for that matter, any of the filters choosen).
>
> Look forward to seeing the results of the repair/update and will post my
> results.
>
> Jim
> W6AIM
>
>
>
> -----Original Message-----
> From: Wayne Burdick [mailto:[hidden email]]
> Sent: Tuesday, February 24, 2015 9:28 AM
> To: jim
> Cc: 'Wes (N7WS)'; [hidden email]
> Subject: Re: [Elecraft] Sherwood Engineering Tests
>
> Jim (et al),
>
> The K3's audio has improved due to three factors in the past couple of
> years:
>
> - a low-noise, low-pass audio filter stage was added to the DSP board,
> eliminating high-pitched CODEC artifacts
>
> - DSP firmware changes were made to correct AGC linearity and eliminate a
> CODEC quantization problem
>
> - main MCU firmware was modified to allow the user to select the lower AF
> cutoff in CW mode (100/200/300 Hz) by adjusting the lower edge of the
> crystal filters
>
> With the above changes in place, we carefully measured the K3's audio
> spectra and compared it to other radios with the same type of class-AB final
> AF amplifier IC (most transceivers fall into this category). They are all
> virtually identical.
>
> Rob, too, told us that the audio spectra he measured on a recent K3 (with
> new synths and the latest DSP and MCU firmware) was significantly improved
> from the K3 he measured several years ago.
>
> While it is possible to reduce audio IMD products even further, this
> typically requires a class-A final audio output stage, which would add
> perhaps 0.5 to 1.0 amps of additional receive-mode current drain (and an
> associated heatsink). That is inconsistent with the K3's intended usage,
> which includes excellent power efficiency for portable applications (Field
> Day/DXpedition/travel). Also, most users would not notice such a subtle
> change.
>
> 73,
> Wayne
> N6KR
>
>
> On Feb 24, 2015, at 8:19 AM, jim <[hidden email]> wrote:
>
>> Wes,
>>
>> I agree, and if you look at a post I made a couple days ago, it states
> that.
>> Sherwood also states his list is sorted on one column and people shud
>> take all factors into account when choosing a radio.
>>
>> I would NOT recommend a K3 for it's audio.  
>>
>> Each person has their needs and should review them carefully.  I would
>> also not recommend a Drake R4-C, even though it is in the top quartile.
>>
>> I will send you a copy of an earlier post that I made.
>>
>>
>> Jim
>> W6AIM
>>
>>
>>
>> -----Original Message-----
>> From: Elecraft [mailto:[hidden email]] On Behalf Of
>> Wes
>> (N7WS)
>> Sent: Tuesday, February 24, 2015 6:12 AM
>> To: [hidden email]
>> Subject: Re: [Elecraft] Sherwood Engineering Tests
>>
>> I'm sure there's a point here and I just fail to see what it is.
>>
>> Rob has stated many times (look for his videos) that one number does
>> not a radio make.  In fact, as best that I know, he doesn't own a K3.
>>
>> Wes  N7WS
>>
>> On 2/23/2015 11:01 PM, jim wrote:
>>> Guys,
>>>
>>> Further, pesky, facts on said Real Radio at
>>> http://www.sherweng.com/table.html .
>>>
>>> Number two on the list.  That is out of 116 receivers listed on the
>>> Sherwood page.
>>>
>>> That puts said Real Radio in the top 3% of the radios Bob Sherwood
>>> has tested for a critical receiver performance parameter.
>>>
>>> BTW, you will have to use the "Page Down" button, more than twice, to
>>> even get a hint of the Kenwood 590.  It is number 20 on the list,
>>> putting it in the top 17%
>>>
>>> Also, important to note, is the Drake R4-C with the Sherwood roofing
>>> mod, listed at number 28.  The R4-C is *ONLY*
>>> 45 (forty five) year old technology and that puts it in the top 23%.  
>>> Yep, FORTY FIVE year old technology.  Yep, top 23 %.
>>>
>>> Just some further, pesky, facts.........................
>>>
>>> Rake
>>>
>>> P.S.  BTW, I learned 45 years ago.  This flies in the face of
>>> someone's comment that I never learn.
>>>
>>> Ho Hum, another pesky fact.............
>>>
>>>
>>>
>>>
>>>
>>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net Please help support this email
>> list: http://www.qsl.net/donate.html Message delivered to
>> [hidden email]
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net Please help support this email
>> list: http://www.qsl.net/donate.html Message delivered to
>> [hidden email]
>
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Jim Bolit
In reply to this post by Brendan Minish
I have so much external **noise** in the shack with whirring fans on the K3
and spinning hard drives that speakers are not seriously used during
operation of my K3 station.  I am using the BOSE QC-15 noise canceling
headphones, with the sensitivity switch set to **high** so the audio control
on the K3 is rarely run past 12 noon (with a corresponding reduction in RF
gain in an effort to hear weaker CW signals better).  If I am not riding the
RF gain, the audio is never past 10 o'clock.

Yea, I hear something.  It is present on my K3 and not on my friend's (NY6C)
rig in an A/B comparison.  I hand carried my K3 from California to Utah for
the CW Sweepstakes contest last November and compared the two.  His was
quiet, I heard artifacts on mine, so I am hoping it is a problem with
hardware/software and willing to have Elecraft look at it.

Jim
W6AIM




-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of
Brendan Minish
Sent: Tuesday, February 24, 2015 10:46 AM
To: Elecraft Reflector
Subject: Re: [Elecraft] Sherwood Engineering Tests

I was one of the people who could most definitely hear the DSP artefacts
above 12Khz prior to the DSP low pass filter upgrade.

The low pass filter upgrade completely resolved it for me, this along with
the various other changes over the years now has the K3 sounding very good
to my ears.  

Do make sure that the speakers and headphones you are using are reasonably
efficient so that the K3 can drive them effectively without having to run
the AF amp 'flat out'  

For speakers I use a couple of old Motorola 2way radio speakers (3 Ohm
impedance I think).
As a headset I generally use a beyerdynmic DT-109 with 50Ohm earpieces, this
works wonderfully with the K3 but as I am a fairly soft talker I made up a
small preamp for the mic element
http://ei6iz.com/?p=28

 

On Tue, 2015-02-24 at 09:48 -0800, Wayne Burdick wrote:
>
...
> Or you can add just the audio filter section as a small daughter board
> for $39 (K3DSPLPF).
>
> The upgrade does improve the spectra as viewed on an audio spectrum
> analyzer, but many operators won't be able to hear the effects by ear.
> Those who can hear them have told us it was a major improvement.
>
> Wayne
> N6KR


--
73
Brendan EI6IZ

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message
delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Jim Bolit
In reply to this post by wayne burdick
Wayne,

Thanks again.  I hear a significant amount of hiss with the AF gain control
at zero.

I am going to send it in and post the results upon return.

Tnx

Jim
W6AIM




-----Original Message-----
From: Wayne Burdick [mailto:[hidden email]]
Sent: Tuesday, February 24, 2015 11:03 AM
To: jim
Cc: 'Wes (N7WS)'; [hidden email]
Subject: Re: [Elecraft] Sherwood Engineering Tests

Jim,

Yes, you have the new DSP boards. I'm sure customer support will check out
your audio as requested.

There will always be noise and hiss with no signal present and gain controls
maximized, because the K3 has a lot of gain in the RX signal path, like any
modern transceiver. But with AF gain, RF gain and preamp settings
appropriately adjusted, even the noise from a very poor antenna will
completely dominate any noise generated within the radio itself. If not, you
have something set up incorrectly, or a hardware issue that CS will be able
to identify.

The new synths are not required just to produce clean audio. It should
already be clean.

73,
Wayne
N6KR


On Feb 24, 2015, at 10:50 AM, jim <[hidden email]> wrote:

> Wayne,
>
> Thanks.
>
> My Serial Number is  04841.  I was told the LPF was "most likely" in
> my radio and I have not taken it apart to see if that is the case.
>
> DSP 1 and DSP 2 are at 02.83
>
> MCU is at 04.86
>
> As I stated in a mail I sent to the reflector, two days ago, I will be
> sending in my K3 on RMA to have you review and update where necessary.  
> I will include a request to have Elecraft look at the audio spectra to
> make sure it is **clean**.
>
> Are the new Synth's needed for better audio performance?  The **noise
> and
> hiss* is present with no signals present in the bandwidth of the 400
> Hz crystal filter (or for that matter, any of the filters choosen).
>
> Look forward to seeing the results of the repair/update and will post
> my results.
>
> Jim
> W6AIM
>
>
>
> -----Original Message-----
> From: Wayne Burdick [mailto:[hidden email]]
> Sent: Tuesday, February 24, 2015 9:28 AM
> To: jim
> Cc: 'Wes (N7WS)'; [hidden email]
> Subject: Re: [Elecraft] Sherwood Engineering Tests
>
> Jim (et al),
>
> The K3's audio has improved due to three factors in the past couple of
> years:
>
> - a low-noise, low-pass audio filter stage was added to the DSP board,
> eliminating high-pitched CODEC artifacts
>
> - DSP firmware changes were made to correct AGC linearity and
> eliminate a CODEC quantization problem
>
> - main MCU firmware was modified to allow the user to select the lower
> AF cutoff in CW mode (100/200/300 Hz) by adjusting the lower edge of
> the crystal filters
>
> With the above changes in place, we carefully measured the K3's audio
> spectra and compared it to other radios with the same type of class-AB
> final AF amplifier IC (most transceivers fall into this category).
> They are all virtually identical.
>
> Rob, too, told us that the audio spectra he measured on a recent K3
> (with new synths and the latest DSP and MCU firmware) was
> significantly improved from the K3 he measured several years ago.
>
> While it is possible to reduce audio IMD products even further, this
> typically requires a class-A final audio output stage, which would add
> perhaps 0.5 to 1.0 amps of additional receive-mode current drain (and
> an associated heatsink). That is inconsistent with the K3's intended
> usage, which includes excellent power efficiency for portable
> applications (Field Day/DXpedition/travel). Also, most users would not
> notice such a subtle change.
>
> 73,
> Wayne
> N6KR
>
>
> On Feb 24, 2015, at 8:19 AM, jim <[hidden email]> wrote:
>
>> Wes,
>>
>> I agree, and if you look at a post I made a couple days ago, it
>> states
> that.
>> Sherwood also states his list is sorted on one column and people shud
>> take all factors into account when choosing a radio.
>>
>> I would NOT recommend a K3 for it's audio.  
>>
>> Each person has their needs and should review them carefully.  I
>> would also not recommend a Drake R4-C, even though it is in the top
quartile.

>>
>> I will send you a copy of an earlier post that I made.
>>
>>
>> Jim
>> W6AIM
>>
>>
>>
>> -----Original Message-----
>> From: Elecraft [mailto:[hidden email]] On Behalf Of
>> Wes
>> (N7WS)
>> Sent: Tuesday, February 24, 2015 6:12 AM
>> To: [hidden email]
>> Subject: Re: [Elecraft] Sherwood Engineering Tests
>>
>> I'm sure there's a point here and I just fail to see what it is.
>>
>> Rob has stated many times (look for his videos) that one number does
>> not a radio make.  In fact, as best that I know, he doesn't own a K3.
>>
>> Wes  N7WS
>>
>> On 2/23/2015 11:01 PM, jim wrote:
>>> Guys,
>>>
>>> Further, pesky, facts on said Real Radio at
>>> http://www.sherweng.com/table.html .
>>>
>>> Number two on the list.  That is out of 116 receivers listed on the
>>> Sherwood page.
>>>
>>> That puts said Real Radio in the top 3% of the radios Bob Sherwood
>>> has tested for a critical receiver performance parameter.
>>>
>>> BTW, you will have to use the "Page Down" button, more than twice,
>>> to even get a hint of the Kenwood 590.  It is number 20 on the list,
>>> putting it in the top 17%
>>>
>>> Also, important to note, is the Drake R4-C with the Sherwood roofing
>>> mod, listed at number 28.  The R4-C is *ONLY*
>>> 45 (forty five) year old technology and that puts it in the top 23%.  
>>> Yep, FORTY FIVE year old technology.  Yep, top 23 %.
>>>
>>> Just some further, pesky, facts.........................
>>>
>>> Rake
>>>
>>> P.S.  BTW, I learned 45 years ago.  This flies in the face of
>>> someone's comment that I never learn.
>>>
>>> Ho Hum, another pesky fact.............
>>>
>>>
>>>
>>>
>>>
>>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net Please help support this
>> email
>> list: http://www.qsl.net/donate.html Message delivered to
>> [hidden email]
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net Please help support this
>> email
>> list: http://www.qsl.net/donate.html Message delivered to
>> [hidden email]
>
>


______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Joseph Trombino, Jr
In reply to this post by Locherbob
Howdy Gang:

I can certainly attest to the fact that the audio in the K3 is very much improved over early serial numbers.

I purchased a K3 way back when...s/n 284 I believe.

After listening to the radio for about 20 minutes I got "fatigued" by the audio....I only kept the radio a few months and sold it.

A few years and several thousand serial numbers later...I purchased a new K3, s/n 44XX, and the audio was greatly improved and was a joy to listen to...I still have the rig but it's been gathering dust since I just love my KX3!!

Elecraft simply doesn't follow the YaeComWood philosophy of making improvements to their rigs by selling the Pro or ProII, Pro III etc forcing you to sell your current rig and buying the new and improved rig.

Elecraft does it the right way and maintains a solid customer base because of their philosophy of users being able to upgrade their rigs and stay current in terms of capability and functionality.

                        73, Joe W2KJ
                        I QRP, therefore I am




______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

kk5na
I guess I have an "old" K3  s/n 2145.

No upgrades, no new DSP, and I have great audio, no audio problems, no
fatigue from listening.

I work every QRP fox I look for and using the built-in speaker.

Maybe I got lucky in my K3 build.

73
Joe KK5NA

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Joe
W2KJ
Sent: Tuesday, February 24, 2015 1:58 PM
To: [hidden email]
Subject: Re: [Elecraft] Sherwood Engineering Tests

Howdy Gang:

I can certainly attest to the fact that the audio in the K3 is very much
improved over early serial numbers.

I purchased a K3 way back when...s/n 284 I believe.

After listening to the radio for about 20 minutes I got "fatigued" by the
audio....I only kept the radio a few months and sold it.

A few years and several thousand serial numbers later...I purchased a new
K3, s/n 44XX, and the audio was greatly improved and was a joy to listen
to...I still have the rig but it's been gathering dust since I just love my
KX3!!

Elecraft simply doesn't follow the YaeComWood philosophy of making
improvements to their rigs by selling the Pro or ProII, Pro III etc forcing
you to sell your current rig and buying the new and improved rig.

Elecraft does it the right way and maintains a solid customer base because
of their philosophy of users being able to upgrade their rigs and stay
current in terms of capability and functionality.

                        73, Joe W2KJ
                        I QRP, therefore I am




______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html Message
delivered to [hidden email]


______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

FW: Sherwood Engineering Tests

Chester Alderman
In reply to this post by Yngvi (TF3Y)


_____________________________________________
From: Chester Alderman [mailto:[hidden email]]
Sent: Tuesday, February 24, 2015 1:59 PM
To: 'Yngvi (TF3Y)'
Cc: 'Elecraft Reflector'
Subject: RE: [Elecraft] Sherwood Engineering Tests


Hi Yvgvi,

I wonder, given atmospheric noise levels, if that is really going to be
noticed by the operator. I seriously doubt It would be noticed in a contest?

73,
Tom - W4BQF


-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Yngvi
(TF3Y)
Sent: Tuesday, February 24, 2015 1:26 PM
To: [hidden email] <mailto:[hidden email]>
Subject: Re: [Elecraft] Sherwood Engineering Tests

These are interesting stats.

One thing I noticed was the apparent loss in sensitivity as measured by
Sherwood. This is probably not a big issue for most these days with the ever
increasing noise levels but for the few in silent locations, incl.
some DXpeditions this might be an issue.

Any comments on this?

73, Yngvi TF3Y
http://www.tf3y.net
       

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: FW: Sherwood Engineering Tests

wayne burdick
Administrator
Some on this list are still mistaking this column of Sherwood's chart as *receiver sensitivity*. I believe it is a measurement of AGC threshold. The K3's receiver sensitivity (MDS) is excellent by any measure; see the "noise floor" column. (Side-note: It's interesting that the preamp-off sensitivity of the tested K3 was -136 dBm, while that of the Flex 6700 was -118 dBm -- an 18-dB difference. One would have to leave the preamp ON much more often with the '6700. As Sherwood noted, this maximizes the '6700's dynamic range, but you'd also be hitting the A/D that much harder.)

73,
Wayne
N6KR



On Feb 24, 2015, at 12:24 PM, "Chester Alderman" <[hidden email]> wrote:

>
>
> _____________________________________________
> From: Chester Alderman [mailto:[hidden email]]
> Sent: Tuesday, February 24, 2015 1:59 PM
> To: 'Yngvi (TF3Y)'
> Cc: 'Elecraft Reflector'
> Subject: RE: [Elecraft] Sherwood Engineering Tests
>
>
> Hi Yvgvi,
>
> I wonder, given atmospheric noise levels, if that is really going to be
> noticed by the operator. I seriously doubt It would be noticed in a contest?
>
> 73,
> Tom - W4BQF
>
>
> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of Yngvi
> (TF3Y)
> Sent: Tuesday, February 24, 2015 1:26 PM
> To: [hidden email] <mailto:[hidden email]>
> Subject: Re: [Elecraft] Sherwood Engineering Tests
>
> These are interesting stats.
>
> One thing I noticed was the apparent loss in sensitivity as measured by
> Sherwood. This is probably not a big issue for most these days with the ever
> increasing noise levels but for the few in silent locations, incl.
> some DXpeditions this might be an issue.
>
> Any comments on this?
>
> 73, Yngvi TF3Y
> http://www.tf3y.net
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: FW: Sherwood Engineering Tests

wayne burdick
Administrator
Just to complete the point about this: The K3 tested probably didn't have its S-meter calibration ("RX gain cal") completed before we sent it to Rob, an oversight on our part. This procedure is fully automated by the K3 Utility program, and definitely would have corrected the sensitivity threshold issue Rob observed.

73,
Wayne
N6KR


On Feb 24, 2015, at 1:54 PM, Wayne Burdick <[hidden email]> wrote:

> Some on this list are still mistaking this column of Sherwood's chart as *receiver sensitivity*. I believe it is a measurement of AGC threshold. The K3's receiver sensitivity (MDS) is excellent by any measure; see the "noise floor" column. (Side-note: It's interesting that the preamp-off sensitivity of the tested K3 was -136 dBm, while that of the Flex 6700 was -118 dBm -- an 18-dB difference. One would have to leave the preamp ON much more often with the '6700. As Sherwood noted, this maximizes the '6700's dynamic range, but you'd also be hitting the A/D that much harder.)
>
> 73,
> Wayne
> N6KR
>
>
>
> On Feb 24, 2015, at 12:24 PM, "Chester Alderman" <[hidden email]> wrote:
>
>>
>>
>> _____________________________________________
>> From: Chester Alderman [mailto:[hidden email]]
>> Sent: Tuesday, February 24, 2015 1:59 PM
>> To: 'Yngvi (TF3Y)'
>> Cc: 'Elecraft Reflector'
>> Subject: RE: [Elecraft] Sherwood Engineering Tests
>>
>>
>> Hi Yvgvi,
>>
>> I wonder, given atmospheric noise levels, if that is really going to be
>> noticed by the operator. I seriously doubt It would be noticed in a contest?
>>
>> 73,
>> Tom - W4BQF
>>
>>
>> -----Original Message-----
>> From: Elecraft [mailto:[hidden email]] On Behalf Of Yngvi
>> (TF3Y)
>> Sent: Tuesday, February 24, 2015 1:26 PM
>> To: [hidden email] <mailto:[hidden email]>
>> Subject: Re: [Elecraft] Sherwood Engineering Tests
>>
>> These are interesting stats.
>>
>> One thing I noticed was the apparent loss in sensitivity as measured by
>> Sherwood. This is probably not a big issue for most these days with the ever
>> increasing noise levels but for the few in silent locations, incl.
>> some DXpeditions this might be an issue.
>>
>> Any comments on this?
>>
>> 73, Yngvi TF3Y
>> http://www.tf3y.net
>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: Sherwood Engineering Tests

Jim Low man
In reply to this post by Locherbob
First of all, congratulations to Elecraft for raising the bar (or at
least jumping higher) to get to Sherwood ranking #2!

This sort of begs the question that I failed to ask when these upgrades
were announced - do I really need to upgrade?
In other words, who is the intended user of this lofty technology?
Will it really improve the performance of my K3 that I can see (hear),
or would I be paying about $200 x 2 (I have the second RX) for
performance that can be measured only with precision lab instruments?

73 de Jim - AD6CW

On 2/23/2015 8:22 PM, Bob Locher wrote:
> The Sherwood ratings on receivers has just been updated to show the K3
> with the new synthesizer. See: http://www.sherweng.com/table.html
>
> Looking good - congratulations to Wayne and Eric!

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
Reply | Threaded
Open this post in threaded view
|

Re: FW: Sherwood Engineering Tests

Barry K3NDM
In reply to this post by wayne burdick
I'm old enough to remember that the most important characteristic of a receiver was sensitivity. Nothing else seemed to matter. Some receivers of the time had 2 RF amplifiers to make sure that they won the sensitivity battle. And, what would happened when a strong signal, not necessarily S9, would appear, bad things happened to your radio. At this point I won't define the date.

This lunacy was being looked at by a number engineers, to include Dr. Ulrich Rhode, W2 something. I forget his call. He said in a series of papers in professional journals and Ham Radio Magazine that sensitivity was not the most important parameter at the time. It would turn out to be LO noise sidebands and dynamic range. That still holds today, and now, IMHO, ultimate rejection should be added. All of this is shown in Sherwood's data. What this all means is that all of the receiver parameters must be looked at to decide what makes a great radio. I suggest a review of some of Rhode's papers. His writings make extremely interesting reading as it addresses this discussion directly.

73,
Barry
K3NDM


----- Original Message -----

From: "Wayne Burdick" <[hidden email]>
To: "Chester Alderman" <[hidden email]>
Cc: "Elecraft Reflector" <[hidden email]>
Sent: Tuesday, February 24, 2015 4:57:23 PM
Subject: Re: [Elecraft] FW: Sherwood Engineering Tests

Just to complete the point about this: The K3 tested probably didn't have its S-meter calibration ("RX gain cal") completed before we sent it to Rob, an oversight on our part. This procedure is fully automated by the K3 Utility program, and definitely would have corrected the sensitivity threshold issue Rob observed.

73,
Wayne
N6KR


On Feb 24, 2015, at 1:54 PM, Wayne Burdick <[hidden email]> wrote:

> Some on this list are still mistaking this column of Sherwood's chart as *receiver sensitivity*. I believe it is a measurement of AGC threshold. The K3's receiver sensitivity (MDS) is excellent by any measure; see the "noise floor" column. (Side-note: It's interesting that the preamp-off sensitivity of the tested K3 was -136 dBm, while that of the Flex 6700 was -118 dBm -- an 18-dB difference. One would have to leave the preamp ON much more often with the '6700. As Sherwood noted, this maximizes the '6700's dynamic range, but you'd also be hitting the A/D that much harder.)
>
> 73,
> Wayne
> N6KR
>
>
>
> On Feb 24, 2015, at 12:24 PM, "Chester Alderman" <[hidden email]> wrote:
>
>>
>>
>> _____________________________________________
>> From: Chester Alderman [mailto:[hidden email]]
>> Sent: Tuesday, February 24, 2015 1:59 PM
>> To: 'Yngvi (TF3Y)'
>> Cc: 'Elecraft Reflector'
>> Subject: RE: [Elecraft] Sherwood Engineering Tests
>>
>>
>> Hi Yvgvi,
>>
>> I wonder, given atmospheric noise levels, if that is really going to be
>> noticed by the operator. I seriously doubt It would be noticed in a contest?
>>
>> 73,
>> Tom - W4BQF
>>
>>
>> -----Original Message-----
>> From: Elecraft [mailto:[hidden email]] On Behalf Of Yngvi
>> (TF3Y)
>> Sent: Tuesday, February 24, 2015 1:26 PM
>> To: [hidden email] <mailto:[hidden email]>
>> Subject: Re: [Elecraft] Sherwood Engineering Tests
>>
>> These are interesting stats.
>>
>> One thing I noticed was the apparent loss in sensitivity as measured by
>> Sherwood. This is probably not a big issue for most these days with the ever
>> increasing noise levels but for the few in silent locations, incl.
>> some DXpeditions this might be an issue.
>>
>> Any comments on this?
>>
>> 73, Yngvi TF3Y
>> http://www.tf3y.net 
>>
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft 
>> Help: http://mailman.qth.net/mmfaq.htm 
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net 
>> Please help support this email list: http://www.qsl.net/donate.html 
>> Message delivered to [hidden email]
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft 
> Help: http://mailman.qth.net/mmfaq.htm 
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net 
> Please help support this email list: http://www.qsl.net/donate.html 
> Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft 
Help: http://mailman.qth.net/mmfaq.htm 
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net 
Please help support this email list: http://www.qsl.net/donate.html 
Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]
12