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Re: Latest Sherwood table

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Bill W4ZV

Re: Latest Sherwood table

> I wonder how such a high performance filter would work in the K3?
Not that its
needed in the K3. However in the interest of science, it might be a worthy
pursuit. It also might push the K3 well ahead of the FT5000 in ultimate
performance.

Not very well since it's at 70 MHz. ;-) The Inrad filters are
already better than whatever is in the FT5000 since Sherwood measured
ultimate rejection in the K3 at 105 dB vs 90 dB for the 5000.

73, Bill W4ZV

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Bob Naumann W5OV

Re: Latest Sherwood table

Is there a non-engineer's guide to the Sherwood table for those of us who
are not engineers?

In particular, the table is sorted by Narrow Spaced Dynamic Range, and I see
that the FT5000 is listed first, but the K3 also gets a 101 in that column,
albeit with a "pf" footnote instead of just an "f".

I decode these footnotes to be "f" = "Measurement was Phase-Noise Limited"
And "pf" = "Measurement was Phase-Noise Limited" and was "with 200 Hz 5-pole
filter"

OK - so why is the FT5000 at the top of the list? Why no indication of what
filter was used in the FT5000?

What is the second sort column for the table? What puts the FT5000 on top?

What does this table really tell us? It seems that both of these receivers
are pretty close as many of the numbers are similarly different from those
listed below them.

When a parameter is higher or lower - which is better? I presume that the
higher the narrow-spaced dynamic range, the better, but what about 100kHz
blocking (for example). Is higher or lower there better? The K3 is a 140 on
that one, and the FT5000 is a "lowly" 127. The Down-conversion Kenwood 590
gets a 144 in this column - is that better or worse than the K3? But, the
590 only gets an 88 in the narrow-spaced dynamic range, so I guess that
means it's much worse?

How does one interpret this data?

73,

Bob W5OV

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Bil Tippett
Sent: Friday, December 31, 2010 6:18 AM
To: [hidden email]
Subject: Re: [Elecraft] Latest Sherwood table

> I wonder how such a high performance filter would work in the K3?
Not that its
needed in the K3. However in the interest of science, it might be a worthy
pursuit. It also might push the K3 well ahead of the FT5000 in ultimate
performance.

Not very well since it's at 70 MHz. ;-) The Inrad filters are
already better than whatever is in the FT5000 since Sherwood measured
ultimate rejection in the K3 at 105 dB vs 90 dB for the 5000.

73, Bill W4ZV

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Adriano Perazio

Re: Latest Sherwood table

Nice !!! Ditto.

py2adr
----- Original Message -----
From: "Bob Naumann" <[hidden email]>
To: "'Bil Tippett'" <[hidden email]>; <[hidden email]>
Sent: Friday, December 31, 2010 10:42 AM
Subject: Re: [Elecraft] Latest Sherwood table

> Is there a non-engineer's guide to the Sherwood table for those of us who
> are not engineers?
>
> In particular, the table is sorted by Narrow Spaced Dynamic Range, and I
> see
> that the FT5000 is listed first, but the K3 also gets a 101 in that
> column,
> albeit with a "pf" footnote instead of just an "f".
>
> I decode these footnotes to be "f" = "Measurement was Phase-Noise Limited"
> And "pf" = "Measurement was Phase-Noise Limited" and was "with 200 Hz
> 5-pole
> filter"
>
> OK - so why is the FT5000 at the top of the list? Why no indication of
> what
> filter was used in the FT5000?
>
> What is the second sort column for the table? What puts the FT5000 on
> top?
>
> What does this table really tell us? It seems that both of these receivers
> are pretty close as many of the numbers are similarly different from those
> listed below them.
>
> When a parameter is higher or lower - which is better? I presume that the
> higher the narrow-spaced dynamic range, the better, but what about 100kHz
> blocking (for example). Is higher or lower there better? The K3 is a 140
> on
> that one, and the FT5000 is a "lowly" 127. The Down-conversion Kenwood
> 590
> gets a 144 in this column - is that better or worse than the K3? But, the
> 590 only gets an 88 in the narrow-spaced dynamic range, so I guess that
> means it's much worse?
>
> How does one interpret this data?
>
> 73,
>
> Bob W5OV
>
>
>
>
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Bil Tippett
> Sent: Friday, December 31, 2010 6:18 AM
> To: [hidden email]
> Subject: Re: [Elecraft] Latest Sherwood table
>
> > I wonder how such a high performance filter would work in the K3?
> Not that its
> needed in the K3. However in the interest of science, it might be a
> worthy
> pursuit. It also might push the K3 well ahead of the FT5000 in ultimate
> performance.
>
> Not very well since it's at 70 MHz. ;-) The Inrad filters are
> already better than whatever is in the FT5000 since Sherwood measured
> ultimate rejection in the K3 at 105 dB vs 90 dB for the 5000.
>
> 73, Bill W4ZV
>
>
>
>
> ______________________________________________________________
> 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
>
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> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html

Don Wilhelm-4

Re: Latest Sherwood table

In reply to this post by Bob Naumann W5OV

Bob,

I can't think of an easy answer - mainly because many or the parameters
tested are in the realmm of engineering, and as such use engineering
terms to achieve some level of communications clarity.

In short, if you do not develop some understanding of the terms, there
is no easy way and must involve some study.

I would suggest two things - first is to try looking up each of the
parameters on Wikipedia, second, do some study of the Receivers section
in the ARRL Handbook to provide you with some understanding of how the
various parameters work together. If you want to gain a little better
understanding, look at the ARRL Testing procedures (for Receivers) - you
really don't have to read the entire test procedure, usually the Purpose
of each test will provide some insight. You can find the ARRL Test
procedures at
http://www.arrl.org/files/file/Technology/tis/info/pdf/Procedure%20Manual%202010%20with%20page%20breaks.pdf

Lastly, some parameters will be more important to one type of operation
than others. Exactly which ones relate to your operating tastes and
style will vary. A contester or avid DXer will want good performance in
the narrow spaced dynamic range because he must work in a section of the
band crowded with signals and does not want the stronger ones to
overload the receiver. If your operating style is more of the ragchew
variety, that same parameter may not be important to you since you will
likely QSY if QRM is nearby rather than trying to "stick it out" and
work within the QRM area of the band.

73,
Don W3FPR

On 12/31/2010 7:42 AM, Bob Naumann wrote:

> Is there a non-engineer's guide to the Sherwood table for those of us who
> are not engineers?
>
> In particular, the table is sorted by Narrow Spaced Dynamic Range, and I see
> that the FT5000 is listed first, but the K3 also gets a 101 in that column,
> albeit with a "pf" footnote instead of just an "f".
>
> I decode these footnotes to be "f" = "Measurement was Phase-Noise Limited"
> And "pf" = "Measurement was Phase-Noise Limited" and was "with 200 Hz 5-pole
> filter"
>
> OK - so why is the FT5000 at the top of the list? Why no indication of what
> filter was used in the FT5000?
>
> What is the second sort column for the table? What puts the FT5000 on top?
>
> What does this table really tell us? It seems that both of these receivers
> are pretty close as many of the numbers are similarly different from those
> listed below them.
>
> When a parameter is higher or lower - which is better? I presume that the
> higher the narrow-spaced dynamic range, the better, but what about 100kHz
> blocking (for example). Is higher or lower there better? The K3 is a 140 on
> that one, and the FT5000 is a "lowly" 127. The Down-conversion Kenwood 590
> gets a 144 in this column - is that better or worse than the K3? But, the
> 590 only gets an 88 in the narrow-spaced dynamic range, so I guess that
> means it's much worse?
>
> How does one interpret this data?
>
> 73,
>
> Bob W5OV
>
>
>
>
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Bil Tippett
> Sent: Friday, December 31, 2010 6:18 AM
> To: [hidden email]
> Subject: Re: [Elecraft] Latest Sherwood table
>
> > I wonder how such a high performance filter would work in the K3?
> Not that its
> needed in the K3. However in the interest of science, it might be a worthy
> pursuit. It also might push the K3 well ahead of the FT5000 in ultimate
> performance.
>
> Not very well since it's at 70 MHz. ;-) The Inrad filters are
> already better than whatever is in the FT5000 since Sherwood measured
> ultimate rejection in the K3 at 105 dB vs 90 dB for the 5000.
>
> 73, Bill W4ZV
>
>
>
>
> ______________________________________________________________
> 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
>
> ______________________________________________________________
> 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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> Please help support this email list: http://www.qsl.net/donate.html
>

Bob Naumann W5OV

Re: Latest Sherwood table

Thank you, Don.

To make what I'm saying clear, I do understand that this is all very complex
and decoding it all takes a deep level of understanding, which I suppose
comes naturally to engineers and people who enjoy that sort of thing. I'm no
longer one of those people. Even though I have been involved in electronics
for decades and was an Electronic Engineering Technician for many years
until I went to "the dark side" of management back in the 80's.

So, I can/could understand what each of the terms means - but I don't see
from the table how they were used to reach a conclusion of which radio is
ranked #1.

I guess that what I'm looking for is an "Executive Summary" with some
answers to my specific questions:

1) Why is the FT5000 at the top of the list? (And not the K3 when they both
get a 101 in the column the table is sorted on?) Is it because the FT5000 is
newer so it goes at the top?

2) Why no indication of what filter was used in the FT5000? (Is that
significant or not?)

3) What is the second sort column for the table? (which I presume "puts the
FT5000 on top" since they seem equivalent in the Narrow Dynamic Range column
with 101 for both).

I think that even if I were to gain enough knowledge to fully explain each
parameter in engineering terms, I would still be guessing at what criteria
Rob used to rank these radios.

A simple explanation like: "Even though the FT-5000 and the K3 have the same
Narrow Dynamic Range measurement, the _______ of the FT5000 puts it ahead of
the K3 in the table".

Make sense?

-Bob W5OV

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Don Wilhelm
Sent: Friday, December 31, 2010 7:54 AM
To: Bob Naumann
Cc: [hidden email]
Subject: Re: [Elecraft] Latest Sherwood table

Bob,

I can't think of an easy answer - mainly because many or the parameters
tested are in the realmm of engineering, and as such use engineering
terms to achieve some level of communications clarity.

In short, if you do not develop some understanding of the terms, there
is no easy way and must involve some study.

I would suggest two things - first is to try looking up each of the
parameters on Wikipedia, second, do some study of the Receivers section
in the ARRL Handbook to provide you with some understanding of how the
various parameters work together. If you want to gain a little better
understanding, look at the ARRL Testing procedures (for Receivers) - you
really don't have to read the entire test procedure, usually the Purpose
of each test will provide some insight. You can find the ARRL Test
procedures at
http://www.arrl.org/files/file/Technology/tis/info/pdf/Procedure%20Manual%20
2010%20with%20page%20breaks.pdf

Lastly, some parameters will be more important to one type of operation
than others. Exactly which ones relate to your operating tastes and
style will vary. A contester or avid DXer will want good performance in
the narrow spaced dynamic range because he must work in a section of the
band crowded with signals and does not want the stronger ones to
overload the receiver. If your operating style is more of the ragchew
variety, that same parameter may not be important to you since you will
likely QSY if QRM is nearby rather than trying to "stick it out" and
work within the QRM area of the band.

73,
Don W3FPR

On 12/31/2010 7:42 AM, Bob Naumann wrote:
> Is there a non-engineer's guide to the Sherwood table for those of us who
> are not engineers?
>
> In particular, the table is sorted by Narrow Spaced Dynamic Range, and I
see
> that the FT5000 is listed first, but the K3 also gets a 101 in that
column,
> albeit with a "pf" footnote instead of just an "f".
>
> I decode these footnotes to be "f" = "Measurement was Phase-Noise Limited"
> And "pf" = "Measurement was Phase-Noise Limited" and was "with 200 Hz
5-pole
> filter"
>
> OK - so why is the FT5000 at the top of the list? Why no indication of
what
> filter was used in the FT5000?
>
> What is the second sort column for the table? What puts the FT5000 on
top?
>
> What does this table really tell us? It seems that both of these receivers
> are pretty close as many of the numbers are similarly different from those
> listed below them.
>
> When a parameter is higher or lower - which is better? I presume that the
> higher the narrow-spaced dynamic range, the better, but what about 100kHz
> blocking (for example). Is higher or lower there better? The K3 is a 140
on
> that one, and the FT5000 is a "lowly" 127. The Down-conversion Kenwood
590

> gets a 144 in this column - is that better or worse than the K3? But, the
> 590 only gets an 88 in the narrow-spaced dynamic range, so I guess that
> means it's much worse?
>
> How does one interpret this data?
>
> 73,
>
> Bob W5OV
>
>
>
>
>
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Bil Tippett
> Sent: Friday, December 31, 2010 6:18 AM
> To: [hidden email]
> Subject: Re: [Elecraft] Latest Sherwood table
>
> > I wonder how such a high performance filter would work in the K3?
> Not that its
> needed in the K3. However in the interest of science, it might be a

worthy

> pursuit. It also might push the K3 well ahead of the FT5000 in ultimate
> performance.
>
> Not very well since it's at 70 MHz. ;-) The Inrad filters are
> already better than whatever is in the FT5000 since Sherwood measured
> ultimate rejection in the K3 at 105 dB vs 90 dB for the 5000.
>
> 73, Bill W4ZV
>
>
>
>
> ______________________________________________________________
> 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
>
> ______________________________________________________________
> 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
>

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Bill W4ZV

Re: Latest Sherwood table

In reply to this post by Bob Naumann W5OV

On Fri, Dec 31, 2010 at 7:42 AM, Bob Naumann <[hidden email]> wrote:

***Correct on both counts.

>
> OK - so why is the FT5000 at the top of the list? Why no indication of what
> filter was used in the FT5000?
>

***The default assumption is always a 500 Hz filter or the closest that the
manufacturer provides, so ~500 Hz results results are NOT footnoted. The
FT5000 measurements were using its standard 600 Hz filter and the K3 is
footnoted for the 400 Hz and 200 Hz measurements. The K3's 5-pole 500 Hz is
NOT footnoted per the assumed convention.

>
> What is the second sort column for the table? What puts the FT5000 on top?
>

***The sort is by 2 kHz IMDDR3 only. Since the FT5000 achieved 101 dB using
its 600 Hz filter, it is listed above the K3 which achieved 95 dB with a 500
Hz filter.

>
> What does this table really tell us? It seems that both of these receivers
> are pretty close as many of the numbers are similarly different from those
> listed below them.
>

***Yes it tells you that for all practical purposes all of the rigs from
Orion up are practically identical. I doubt you would notice the difference
in 95 dB versus 101 dB in most real world cases.

>
> When a parameter is higher or lower - which is better? I presume that the
> higher the narrow-spaced dynamic range, the better, but what about 100kHz
> blocking (for example). Is higher or lower there better? The K3 is a 140 on
> that one, and the FT5000 is a "lowly" 127. The Down-conversion Kenwood 590
> gets a 144 in this column - is that better or worse than the K3? But, the
> 590 only gets an 88 in the narrow-spaced dynamic range, so I guess that
> means it's much worse?
>
> How does one interpret this data?
>

***Higher blocking (BDR) is better. BDR is important in a multi-transmitter
environment or if you have a very near neighbor. If you had either of these
situations, you might opt for the higher BDR result if the rigs' IMDDR3
results were similar. Phase noise (both TX and RX) is another very
important parameter in multi-transmitter environments (where the K3 also
shines).

Hope this helps! 73 & HNY to all!

Bill W4ZV
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Nate Bargmann

Re: Latest Sherwood table

* On 2010 31 Dec 08:43 -0600, Bill Tippett wrote:
> On Fri, Dec 31, 2010 at 7:42 AM, Bob Naumann <[hidden email]> wrote:
>
> > What is the second sort column for the table? What puts the FT5000 on top?
> >
>
> ***The sort is by 2 kHz IMDDR3 only. Since the FT5000 achieved 101 dB using
> its 600 Hz filter, it is listed above the K3 which achieved 95 dB with a 500
> Hz filter.

IMO, while Bob's efforts have long been to document very close dynamic
range, it seems that this one singular focus tends to skew the table
somewhat (I'm not just saying that because the K3 is now presumed
"second rate" by those who don't understand all of the parameters fully).
I say it because I think one must take all parameters into account as I
think they show that focusing strictly on one area leads to deficiencies
in other areas.

If, for instance, the Yaesu engineers consciously set out to acheive the
top spot based soley on 2 kHz BDR, they won that battle but lost the
war as other numbers indicate poorer performance for the FT-5000. IMO,
the K3 should rank higher as the overall numbers are better and more
consistent than the FT-5000. But, it's Bob's data and website and he
has decided how to rank the various transceivers.

> > What does this table really tell us? It seems that both of these receivers
> > are pretty close as many of the numbers are similarly different from those
> > listed below them.
> >
>
> ***Yes it tells you that for all practical purposes all of the rigs from
> Orion up are practically identical. I doubt you would notice the difference
> in 95 dB versus 101 dB in most real world cases.

And this is where other factors do begin to come into play. After the
considering them, the K3 came in on top by a wide margin *for me*.
YMMV.

73, es HNY,

de Nate N0NB >>

--

"The optimist proclaims that we live in the best of all
possible worlds. The pessimist fears this is true."

Ham radio, Linux, bikes, and more: http://n0nb.us/index.html
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Bill W4ZV

Re: Latest Sherwood table

In reply to this post by Bob Naumann W5OV

On Fri, Dec 31, 2010 at 7:42 AM, Bob Naumann <[hidden email]> wrote:

Is there a non-engineer's guide to the Sherwood table for those of us who
> are not engineers?
>

On Sherwood's main page, there's a very good presentation at the upper left:

Roofing Filters, Transmitted BW & Receiver Performnce

*Dayton Contest University 2008 *

Slide Show with Audio
(wmv<http://www.sherweng.com/audio/Sherwood_CU_2008_final_b.wmv>)

Slide Show only
(ppt<http://www.sherweng.com/documents/NC0B-Contest-U-2008-9.ppt>or
pdf <http://www.sherweng.com/documents/NC0B-Contest-U-2008-9.pdf>) - Audio
only (mp3 <http://www.sherweng.com/audio/CU-Presentation-Edited-2a.mp3>)

Click to view or listen or to save, right click & Save Target/Link

Rob covers many of the issues you'll see on his Receiver Test Data page.

73, Bill W4ZV
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Bill Steffey NY9H

Re: Latest Sherwood table

hey guys ....

FACE IT ;
THE YAESU IS ON TOP
let someone have their 15 minutes,,,, ok 3 minutes,,,

TIMES UP ......

BILL /3
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Guy, K2AV

Re: Latest Sherwood table

The Yaesu "car" may be on top because of slightly higher
"acceleration", but I'm watching what people are driving around the
race track, ya know those guys who have to add *everything* up to
finish the race in front.

The Yakencom boys keep throwing something or the other overboard to
try and match the K3. And I would have thought that the Kenwood 590
would have finished in better shape (that's what's new on the list
BTW). If you bought your K3 in a fit of p***s envy, you're sure to
get knocked down on some list sooner or later. But if you bought it
for all those high numbers AND reasonable cost AND two equally
excellent receivers AND true diversity AND customer support AND
constantly evolving firmware AND configurability AND an owner who's
always listening to the troops AND ... , then the other guys on the
list don't really compare.

I note that the one other REALLY sharp RX on the list (Perseus) does
not have a transmitter inside it's case.

PS, after listening to a friend for a while last night, I recommended
a 590 to him. Whatever else, the K3 has had an enormous effect on the
state of the art.

73, Guy.

On Fri, Dec 31, 2010 at 10:22 AM, Bill NY9H <[hidden email]> wrote:

> hey guys ....
>
>
> FACE IT ;
> THE YAESU IS ON TOP
> let someone have their 15 minutes,,,, ok 3 minutes,,,
>
>
>
>
>
>
> TIMES UP ......
>
>
>
> BILL /3
> ______________________________________________________________
> Elecraft mailing list
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Byron N6NUL

Re: Latest Sherwood table

In reply to this post by Nate Bargmann

Every time this table comes out I am pleasantly surprised at how
competitive the K2 remains after so many years. In nearly every
category except the sort criteria, the classic kit radio is still
right up there!

But, then, I am looking forward to building my own K2, so I've got
some rose-tinted glasses on. 20 dB is a lot.

73, Byron N6NUL
K1 #2799

On Fri, Dec 31, 2010 at 7:06 AM, Nate Bargmann <[hidden email]> wrote:

> * On 2010 31 Dec 08:43 -0600, Bill Tippett wrote:
>> On Fri, Dec 31, 2010 at 7:42 AM, Bob Naumann <[hidden email]> wrote:
>>
>> > What is the second sort column for the table? What puts the FT5000 on top?
>> >
>>
>> ***The sort is by 2 kHz IMDDR3 only. Since the FT5000 achieved 101 dB using
>> its 600 Hz filter, it is listed above the K3 which achieved 95 dB with a 500
>> Hz filter.
>
> IMO, while Bob's efforts have long been to document very close dynamic
> range, it seems that this one singular focus tends to skew the table
> somewhat (I'm not just saying that because the K3 is now presumed
> "second rate" by those who don't understand all of the parameters fully).
> I say it because I think one must take all parameters into account as I
> think they show that focusing strictly on one area leads to deficiencies
> in other areas.

--
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org
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Jim Brown-10

Re: Latest Sherwood table

In reply to this post by Bob Naumann W5OV

On 12/31/2010 4:42 AM, Bob Naumann wrote:
> Is there a non-engineer's guide to the Sherwood table for those of us who
> are not engineers?

Certainly one of us could write up a guide to it, but a better way is
for you to find and study the material ARRL has written about this to go
along with their own lab tests. Search the product review section of
the ARRL website. Not a member? You should be. :)

73, Jim K9YC
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george fritkin

Re: Latest Sherwood table

The numbers are there and pretty straight forward. What they really are saying
is that unless you are operating under very stressful conditions, you can pony
up your money and take your choice. I have 2K3s, 1 Eagle, 1 TS590, 1 ORION ll,
and 1 FT5K. And I have many other radios. At this level the performance is a
given. It is a matter of price, features, and value and no chart is going to
help you decide based on those criteria.

George, W6GF

PS: The customer service of the company is a VERY big factor in my book. Think
about that!!

________________________________
From: Jim Brown <[hidden email]>
To: [hidden email]
Sent: Fri, December 31, 2010 9:22:56 AM
Subject: Re: [Elecraft] Latest Sherwood table

On 12/31/2010 4:42 AM, Bob Naumann wrote:
> Is there a non-engineer's guide to the Sherwood table for those of us who
> are not engineers?

Certainly one of us could write up a guide to it, but a better way is
for you to find and study the material ARRL has written about this to go
along with their own lab tests. Search the product review section of
the ARRL website. Not a member? You should be. :)

73, Jim K9YC
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Kok Chen

Re: Latest Sherwood table

In reply to this post by Bob Naumann W5OV

On Dec 31, 2010, at 12/31 6:22 AM, Bob Naumann wrote:

> 1) Why is the FT5000 at the top of the list? (And not the K3 when
> they both get a 101 in the column the table is sorted on?) Is it
> because the FT5000 is newer so it goes at the top?

I don't know if it is Rob Sherwood's rationale, but when you look at
all the footnotes, you will see that the K3 required a narrower
roofing filter to achieve the same close-in dynamic range as the
FT-5000.

So, going by the numbers alone, the FT-5000 does have better close in
dynamic range. The Radcom (June 2010) and QST (December 2010) reviews
show even larger differences.

73
Chen, W7AY

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juergen piezo

Re: Latest Sherwood table

In reply to this post by Bill W4ZV

Hi Bill

I understand the differences in IF frequencies.

The question still remains, how much extra IMD dynamic could be squeezed from the K3 if high performance 8mhz roofing filters were used. We have seen no data on the K3 filters that quantified their impact on IMD dynamic range.

PA3AKE has shown that careful selection of crystals and building a roofing with due care contributes a significant amount to the ultimate IMD dynamic range.

http://www.xs4all.nl/~martein/pa3ake/hmode/roofer_intro.html

I wonder if a company like Network Sciences did build an improved 8 mhz filter how much performance increase we would see. Surely if a 20db jump in IMD dynamic range can be achieved at 70mhz, imagine what the improvement would be at 8mhz! We will never know unless someone tries.

73
John

--- On Fri, 12/31/10, Bil Tippett <[hidden email]> wrote:

> From: Bil Tippett <[hidden email]>
> Subject: Re: [Elecraft] Latest Sherwood table
> To: [hidden email]
> Date: Friday, December 31, 2010, 4:18 AM
> > I wonder how such a high
> performance filter would work in the K3?
> Not that its
> needed in the K3. However in the interest of science,
> it might be a worthy
> pursuit. It also might push the K3 well ahead of the FT5000
> in ultimate
> performance.
>
> Not very well since it's at 70 MHz. ;-) The
> Inrad filters are
> already better than whatever is in the FT5000 since
> Sherwood measured
> ultimate rejection in the K3 at 105 dB vs 90 dB for the
> 5000.
>
> 73, Bill W4ZV
>
>
>
>
> ______________________________________________________________
> 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
>

Bill W4ZV

Re: Latest Sherwood table

On Fri, Dec 31, 2010 at 5:00 PM, juergen <[hidden email]> wrote:

>
> The question still remains, how much extra IMD dynamic could be squeezed
> from the K3 if high performance 8mhz roofing filters were used. We have seen
> no data on the K3 filters that quantified their impact on IMD dynamic range.
>

I believe the relevant question is "Who cares?" I don't because I don't
feel I need 120 dB of dynamic range. It's one thing to take the FT2000 from
~66 dB to 86 dB, but taking the K3 from ~100 to 120 dB is a "don't care"
unless TX signals become a LOT cleaner than they are today.

73 & HNY to all!

Bill W4ZV
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Joe Subich, W4TV-4

Re: Latest Sherwood table

In reply to this post by juergen piezo

>> I wonder if a company like Network Sciences did build an improved 8
>> mhz filter how much performance increase we would see. Surely if
>> a 20db jump in IMD dynamic range can be achieved at 70mhz, imagine
>> what the improvement would be at 8mhz! We will never know unless
>> someone tries.

The claimed jump in dynamic range in the FT-2000 with the NS/AC0C
filter is entirely due to the ability of that filter to reduce the
level of the IMD causing signals at +/- 2 KHz (outside the "window").
If you study the AC0C information, you will see the response of the
filter is down about 35 dB at +/- 2KHz. From a theoretical
consideration, reducing the interfering signals by 35 dB should
reduce the IMD by 70 dB!

This performance would indicate that the NS/AC0C filter is probably
protecting the second mixer and second IF but does nothing to solve
the improper (narrow band/reactive) termination of the first mixer
or issues of IMD generated in the noise blanker (even when the NB
is off).

73,

... Joe, W4TV

On 12/31/2010 5:00 PM, juergen wrote:

> Hi Bill
>
> I understand the differences in IF frequencies.
>
> The question still remains, how much extra IMD dynamic could be
> squeezed from the K3 if high performance 8mhz roofing filters were
> used. We have seen no data on the K3 filters that quantified their
> impact on IMD dynamic range.
>
> PA3AKE has shown that careful selection of crystals and building a
> roofing with due care contributes a significant amount to the
> ultimate IMD dynamic range.
>
> http://www.xs4all.nl/~martein/pa3ake/hmode/roofer_intro.html
>
> I wonder if a company like Network Sciences did build an improved 8
> mhz filter how much performance increase we would see. Surely if a
> 20db jump in IMD dynamic range can be achieved at 70mhz, imagine what
> the improvement would be at 8mhz! We will never know unless someone
> tries.
>
> 73 John
>
>
> --- On Fri, 12/31/10, Bil Tippett<[hidden email]> wrote:
>
>> From: Bil Tippett<[hidden email]> Subject: Re: [Elecraft]
>> Latest Sherwood table To: [hidden email] Date: Friday,
>> December 31, 2010, 4:18 AM
>>> I wonder how such a high
>> performance filter would work in the K3? Not that its needed in the
>> K3. However in the interest of science, it might be a worthy
>> pursuit. It also might push the K3 well ahead of the FT5000 in
>> ultimate performance.
>>
>> Not very well since it's at 70 MHz. ;-) The Inrad filters are
>> already better than whatever is in the FT5000 since Sherwood
>> measured ultimate rejection in the K3 at 105 dB vs 90 dB for the
>> 5000.
>>
>> 73, Bill W4ZV
>>
>>
>>
>>
>> ______________________________________________________________
>> 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
>>
>
>
>
> ______________________________________________________________
> 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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>

wayne burdick

Re: Latest Sherwood table

Administrator

In reply to this post by juergen piezo

Both the Inrad and Elecraft filters use crystals that are hand-
screened for low IMD. We built several high-performance test fixtures
for ourselves and Inrad to make sure this was done consistently.

A slight improvement may be possible, but it would probably double the
cost of the filters. The K3's receive IMD numbers are already excellent.

73,
Wayne
N6KR

On Dec 31, 2010, at 2:00 PM, juergen wrote:

> Hi Bill
>
> I understand the differences in IF frequencies.
>
> The question still remains, how much extra IMD dynamic could be
> squeezed from the K3 if high performance 8mhz roofing filters were
> used. We have seen no data on the K3 filters that quantified their
> impact on IMD dynamic range.
>
> PA3AKE has shown that careful selection of crystals and building a
> roofing with due care contributes a significant amount to the
> ultimate IMD dynamic range.
>
> http://www.xs4all.nl/~martein/pa3ake/hmode/roofer_intro.html
>
> I wonder if a company like Network Sciences did build an improved 8
> mhz filter how much performance increase we would see. Surely if a
> 20db jump in IMD dynamic range can be achieved at 70mhz, imagine
> what the improvement would be at 8mhz! We will never know unless
> someone tries.
>
> 73
> John
>
>
> --- On Fri, 12/31/10, Bil Tippett <[hidden email]> wrote:
>
>> From: Bil Tippett <[hidden email]>
>> Subject: Re: [Elecraft] Latest Sherwood table
>> To: [hidden email]
>> Date: Friday, December 31, 2010, 4:18 AM
>>> I wonder how such a high
>> performance filter would work in the K3?
>> Not that its
>> needed in the K3. However in the interest of science,
>> it might be a worthy
>> pursuit. It also might push the K3 well ahead of the FT5000
>> in ultimate
>> performance.
>>
>> Not very well since it's at 70 MHz. ;-) The
>> Inrad filters are
>> already better than whatever is in the FT5000 since
>> Sherwood measured
>> ultimate rejection in the K3 at 105 dB vs 90 dB for the
>> 5000.
>>
>> 73, Bill W4ZV
>>
>>
>>
>>
>> ______________________________________________________________
>> 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
>>
>
>
>
> ______________________________________________________________
> Elecraft mailing list
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>
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AD4C2009

receivers performance data

In reply to this post by george fritkin

here is something I found on the net that will help others to understand better the performance data tables:

Here a few measurements of receivers, using 500Hz filters.
MDS is a measure of sensitivity. -135dBm is 10dB more sensitive than -125dBm. This number doesn't matter very much in what you actually hear. The real test is if you hear a very noticeable noise increase when you connect an antenna to the receiver. If you hear an obvious noise increase when you connect an antenna instead of a dummy load, your receiver is sensitive enough! You should check sensitivity at the quietest time with the narrowest selectivity you use on every antenna you use.
Contrary to folklore and hyperbole, there isn't a receiver sold today that can dig into noise more than others on CW based on sensitivity or the use of a DSP or multiple DSP systems. The exceptions are:

Increased selectivity will reduce noise
Poor AGC design or detector problems can cause mixing of signals and noise
If you read a review that claims a receiver made weak signals appear from nowhere, you better keep a wary eye on the rest of the review. It is possible for a receiver to be abnormally bad, but it is not possible for a receiver to work better than other properly working receivers based on sensitivity.
BDR is blocking dynamic range. This is the point where a strong signal either 2 or 10kHz just starts to make your receiver lose sensitivity. The bigger the number the better, ESPECIALLY at 2kHz spacing. The number you want here is probably around 80dB or more if you live in a reasonably quiet location and work weak signals on crowded bands. If you run two transmitters on the same band or have a neighbor who operates near your frequency, you almost certainly need more dynamic range. I'm in a very quiet rural location and have very directive antennas, and 80dB blocking DR suits my requirements just fine most of the time.
IMDR is intermodulation dynamic range. This is the single most important number when comparing receivers. This is where two or more strong close-frequency signals mix and generate a new phantom signal or multiple tones in a adjacent frequency SSB signal mix with themselves and make what sounds like splatter. The measurement is made just at the point where the phantom signal level is high enough to interfere with the weakest signal your receiver can detect. IMDR is a measure of how badly your own receiver causes problems you might blame on other people. Bigger numbers mean better receivers. It is most important the 2kHz number be good. The 10kHz test number doesn't mean nearly as much, because almost any radio is good enough at 10kHz or wider. Some number above 80dB is enough to stay out of trouble 99% of the time. If you are in a noisy location, you obviously need less performance. 85dB keeps my receivers at the point where poor quality external signals
cause nearly all off-frequency problems. With 85dB IM3DR only a few of the strongest stations cause my receiver to make its own internal problems.

"If freedom means something,it is the right to tell others what they don't want to hear" –George Orwell

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Jan Erik Holm

Re: Latest Sherwood table

In reply to this post by Joe Subich, W4TV-4

Is this a known issue with the FT-2000?
/SM2EKM
------------
On 2010-12-31 23:31, Joe Subich, W4TV wrote:
>
> or issues of IMD generated in the noise blanker (even when the NB
> is off).
>
> 73,
>
> ... Joe, W4TV
>
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