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Sherwood Engineering Tests

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Phil Wheeler-2

Re: Sherwood Engineering Tests

Of course not, Jim -- but most of us didn't *need*
to buy Elecraft either :-)

Staying at the head of the pack does take the
upgrade. But I cheated: With only one usable ear,
no Sub RX to upgrade!

Phil W7OX (in Torrance)

On 2/24/15 5:35 PM, Jim Lowman wrote:

> 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

Jim AB3CV

Re: Sherwood Engineering Tests

In my case I want my K3 to be the best it can be as I have in the past
taken it to FD.

I also work weak signals and want to ensure that interference from nearby
signals will be minimized.

But mainly I want to be able to work 630m and below without a minimum of
fuss.

The new synth(s) allow for all of that.

jim ab3cv
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Re: Sherwood Engineering Tests

In reply to this post by Phil Wheeler-2

How about this. Forget the upgrade, save the money, sell your dual RX K3 and buy the FLEX.......then you are #1

George, W6GF

Sent from my iPad

> On Feb 24, 2015, at 6:11 PM, Phil Wheeler <[hidden email]> wrote:
>
> Of course not, Jim -- but most of us didn't *need* to buy Elecraft either :-)
>
> Staying at the head of the pack does take the upgrade. But I cheated: With only one usable ear, no Sub RX to upgrade!
>
> Phil W7OX (in Torrance)
>
>> On 2/24/15 5:35 PM, Jim Lowman wrote:
>> 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
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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Phil Wheeler-2

Re: Sherwood Engineering Tests

I'm not into computer-focused rigs: Like my old
fashioned dials, George :-)

K3/P3/KPA500/KAT500 is likely my ultimate station!

73, Phil W7OX

On 2/24/15 6:37 PM, George Fritkin wrote:

> How about this. Forget the upgrade, save the money, sell your dual RX K3 and buy the FLEX.......then you are #1
>
> George, W6GF
>
> Sent from my iPad
>
>> On Feb 24, 2015, at 6:11 PM, Phil Wheeler <[hidden email]> wrote:
>>
>> Of course not, Jim -- but most of us didn't *need* to buy Elecraft either :-)
>>
>> Staying at the head of the pack does take the upgrade. But I cheated: With only one usable ear, no Sub RX to upgrade!
>>
>> Phil W7OX (in Torrance)
>>
>>> On 2/24/15 5:35 PM, Jim Lowman wrote:
>>> 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

Stewart@twinwood

Re: FW: Sherwood Engineering Tests

In reply to this post by Barry K3NDM

I can't help thinking that we are getting to a point where this number chasing
is irrelevant.

Until high noise levels caused by EMI and the poor transmitted signals during DX
hunting and contests are eliminated, further improvements in receive performance
figures are unlikely to be of much practical value.

My 2p's worth...

73
Stewart G3RXQ

On Wed, 25 Feb 2015 01:56:22 +0000 (UTC), [hidden email] wrote:
> 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
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>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
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>
> ______________________________________________________________
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>
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>
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>
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Elecraft mailing list

Re: Sherwood Engineering Tests

In reply to this post by Locherbob

Wayne,

Will other radios that have the revised synthesizer board upgraded in the field need to perform the receive gain calibration in order to correct the AGC threshold issue as well?

Is this something that will change upon installing the new board?

73,

Rob

KB2KUU

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

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wayne burdick

Re: Sherwood Engineering Tests

Administrator

On Feb 25, 2015, at 9:36 AM, Rob S. via Elecraft <[hidden email]> wrote:

> Wayne,
>
> Will other radios that have the revised synthesizer board upgraded in the field need to perform the receive gain calibration in order to correct the AGC threshold issue as well?
> Is this something that will change upon installing the new board?

No. This only affected Rob's test K3 because we apparently missed this step when we sent it to him.

Wayne
N6kR

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Jim Bolit

Re: FW: Sherwood Engineering Tests

In reply to this post by Stewart@twinwood

Progress lurches forward.

Someone I am sure asked "what are we going to use this high temperature
material for, we are never going to the moon"

Jim
W6AIM

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of
Stewart
Sent: Wednesday, February 25, 2015 12:11 AM
To: [hidden email]; Burdick, Wayne
Cc: elecraft
Subject: Re: [Elecraft] FW: Sherwood Engineering Tests

I can't help thinking that we are getting to a point where this number
chasing is irrelevant.

Until high noise levels caused by EMI and the poor transmitted signals
during DX hunting and contests are eliminated, further improvements in
receive performance figures are unlikely to be of much practical value.

My 2p's worth...

73
Stewart G3RXQ

On Wed, 25 Feb 2015 01:56:22 +0000 (UTC), [hidden email] wrote:
> 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,
> 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:

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]
>
> ______________________________________________________________
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Guy Olinger K2AV

Re: Sherwood Engineering Tests

In reply to this post by wayne burdick

Are you sending him a replacement so he can redo the figures?

73, Guy.

On Wed, Feb 25, 2015 at 12:54 PM, Wayne Burdick <[hidden email]> wrote:

> On Feb 25, 2015, at 9:36 AM, Rob S. via Elecraft <[hidden email]>
> wrote:
>
> > Wayne,
> >
> > Will other radios that have the revised synthesizer board upgraded in
> the field need to perform the receive gain calibration in order to correct
> the AGC threshold issue as well?
> > Is this something that will change upon installing the new board?
>
>
> No. This only affected Rob's test K3 because we apparently missed this
> step when we sent it to him.
>
> Wayne
> N6kR
>
> ______________________________________________________________
> 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]
>

Scott Manthe-2

Re: Sherwood Engineering Tests

This is a very good idea. As we've seen from the "crappy audio" urban
legends about the K3, misinformation can take hold and never let go on
the Internet. We'll be hearing about the K3 AGC issues for years unless
Rob posts revised information. Bet on it. Wayne, send Rob another rig to
test, please!

73,
Scott, N9AA

On 2/25/15 10:38 PM, Guy Olinger K2AV wrote:

> Are you sending him a replacement so he can redo the figures?
>
> 73, Guy.
>
> On Wed, Feb 25, 2015 at 12:54 PM, Wayne Burdick <[hidden email]> wrote:
>
>> On Feb 25, 2015, at 9:36 AM, Rob S. via Elecraft <[hidden email]>
>> wrote:
>>
>>> Wayne,
>>>
>>> Will other radios that have the revised synthesizer board upgraded in
>> the field need to perform the receive gain calibration in order to correct
>> the AGC threshold issue as well?
>>> Is this something that will change upon installing the new board?
>>
>> No. This only affected Rob's test K3 because we apparently missed this
>> step when we sent it to him.
>>
>> Wayne
>> N6kR
>>
>>