Empathy List Archives

FS

Frank Stellmach

Sat, Oct 26, 2019 11:58 AM

Now it's official, that a redesigned RoHS compliant version will be
available December 1st:

https://www.meilhaus.de/en/3458a.htm

What we've been told on our recent German volt-nuts meeting end of May:

It is obviously a layout redesign only, the schematics should be exactly
the same.

Only the case form was changed from through-hole to SMD, and terminated
parts have been updated to active parts.. maybe some minor schematic
change had to be done.

The overall circuits, firmware and so on are plug and place identical
(form, fit, function), so the new, much smaller boards can be used as
spare parts in old instruments. Therefore, all specifications and
manuals are identical.. a pity.. it was hoped for, that the
specifications would be improved.

The redesign has been done outside of Keysight, it was a German
Engineering bureau, being familiar with RoHS requirements.

Frank

Now it's official, that a redesigned RoHS compliant version will be available December 1st: https://www.meilhaus.de/en/3458a.htm What we've been told on our recent German volt-nuts meeting end of May: It is obviously a layout redesign only, the schematics should be exactly the same. Only the case form was changed from through-hole to SMD, and terminated parts have been updated to active parts.. maybe some minor schematic change had to be done. The overall circuits, firmware and so on are plug and place identical (form, fit, function), so the new, much smaller boards can be used as spare parts in old instruments. Therefore, all specifications and manuals are identical.. a pity.. it was hoped for, that the specifications would be improved. The redesign has been done outside of Keysight, it was a German Engineering bureau, being familiar with RoHS requirements. Frank

PK

Poul-Henning Kamp

Sat, Oct 26, 2019 1:56 PM

In message 8fbd1ccb-9fa6-0c6f-7c7f-65a98b029922@freenet.de, Frank Stellmach w
rites:

Therefore, all specifications and manuals are identical.. a pity..
it was hoped for, that the specifications would be improved.

How or what did you expect them to improve ?

Improving the long term stability of the voltage and ohm references
would be nice, but either one would increase the price by 10% or so,
because we would be into "buy ten throw 9 away" territory.

Anything else which could deliver relevant improvements gets to be
complicated and expensive:

Battery power + optical interface could possibly reduce the noise
a little bit.

A custom input connector could possibly reduce thermal sensitivity.

External clock input could allow you to do synchronized sampling.

And yeah, you could change the interface to be SCPI, breaking all
softwre ever written for that model...

So all in all: I would hate to be pointed at and told "make a better one".

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

-------- In message <8fbd1ccb-9fa6-0c6f-7c7f-65a98b029922@freenet.de>, Frank Stellmach w rites: >Therefore, all specifications and manuals are identical.. a pity.. >it was hoped for, that the specifications would be improved. How or what did you expect them to improve ? Improving the long term stability of the voltage and ohm references would be nice, but either one would increase the price by 10% or so, because we would be into "buy ten throw 9 away" territory. Anything else which could deliver relevant improvements gets to be complicated and expensive: Battery power + optical interface could *possibly* reduce the noise a little bit. A custom input connector could *possibly* reduce thermal sensitivity. External clock input *could* allow you to do synchronized sampling. And yeah, you could change the interface to be SCPI, breaking all softwre ever written for that model... So all in all: I would hate to be pointed at and told "make a better one". -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.

FS

Frank Stellmach

Sat, Oct 26, 2019 4:27 PM

Poul-Henning,

it was the KS representative on our meeting, who expected an
updated/improved specification from the re-validation process, as the
new prototypes obviously performed better than the existing 3458As, in
some (undisclosed) parameters.

The specification origins from the earliest version of 1988. It was
never being updated, even after HP changed the 40k reference resistor
from a hermetical ~ S102C technology to a VHP101 from about 1995
onwards, which in reality performs much better than the original
resistor at 1ppm/K and 10ppm/year.
The VHP101 is an oil-filled, T.C. compensated type, who might have
~0.3ppm/K and 2ppm/6 years drift only, even if Vishay generally makes
very generous specifications.

Already hp or at least KS might have challenged / tested this during
their recent validation
They also might have improved the resistor network for the different Ohm
ranges for better T.C., as well as the mediocre DCI shunts.

Same goes for the DCV specification, they could have simply validated a
metrology grade specification, i.e. operating temperature from 18 to
38°C, and validating a LTZ1000 reference at 55..65°C with <2ppm/year,
<0.05ppm/K stability, with only small changes in design: 12 or 12.5k
instead of 15k, use of non-A version, T.C. trimming of the LTZ circuit,
and a proper thermally shielded case.
They only would have had to make a new validation of such a metrology
grade specification.
The BOM and monitoring cost would be lower, as yield would be higher
(near 100%), and they may have demanded even more money for that.

Maybe they could have modified the A/D converter firmware a bit, to
compensate the T.C. of the ADC resistor network by implementing an 'ACAL
converter' phase from time to time (measuring briefly the network gain
=> CAL? 72). That would also solve the U180 drift problem.

I also don't like proposals or assumptions, that KS should or would
design a completely new and improved 3458, I really think that they
suffer from brain-drain to do so.

But with those few small modifications, they really could have improved
the specification greatly to attack FLUKEs new Reference DMMs.

Frank

In message 8fbd1ccb-9fa6-0c6f-7c7f-65a98b029922@freenet.de, Frank Stellmach w
rites:

Therefore, all specifications and manuals are identical.. a pity..
it was hoped for, that the specifications would be improved.

How or what did you expect them to improve ?

Improving the long term stability of the voltage and ohm references
would be nice, but either one would increase the price by 10% or so,
because we would be into "buy ten throw 9 away" territory.

Anything else which could deliver relevant improvements gets to be
complicated and expensive:

Battery power + optical interface could possibly reduce the noise
a little bit.

A custom input connector could possibly reduce thermal sensitivity.

External clock input could allow you to do synchronized sampling.

And yeah, you could change the interface to be SCPI, breaking all
softwre ever written for that model...

So all in all: I would hate to be pointed at and told "make a better one".

Poul-Henning, it was the KS representative on our meeting, who expected an updated/improved specification from the re-validation process, as the new prototypes obviously performed better than the existing 3458As, in some (undisclosed) parameters. The specification origins from the earliest version of 1988. It was never being updated, even after HP changed the 40k reference resistor from a hermetical ~ S102C technology to a VHP101 from about 1995 onwards, which in reality performs much better than the original resistor at 1ppm/K and 10ppm/year. The VHP101 is an oil-filled, T.C. compensated type, who might have ~0.3ppm/K and 2ppm/6 years drift only, even if Vishay generally makes very generous specifications. Already hp or at least KS might have challenged / tested this during their recent validation They also might have improved the resistor network for the different Ohm ranges for better T.C., as well as the mediocre DCI shunts. Same goes for the DCV specification, they could have simply validated a metrology grade specification, i.e. operating temperature from 18 to 38°C, and validating a LTZ1000 reference at 55..65°C with <2ppm/year, <0.05ppm/K stability, with only small changes in design: 12 or 12.5k instead of 15k, use of non-A version, T.C. trimming of the LTZ circuit, and a proper thermally shielded case. They only would have had to make a new validation of such a metrology grade specification. The BOM and monitoring cost would be lower, as yield would be higher (near 100%), and they may have demanded even more money for that. Maybe they could have modified the A/D converter firmware a bit, to compensate the T.C. of the ADC resistor network by implementing an 'ACAL converter' phase from time to time (measuring briefly the network gain => CAL? 72). That would also solve the U180 drift problem. I also don't like proposals or assumptions, that KS should or would design a completely new and improved 3458, I really think that they suffer from brain-drain to do so. But with those few small modifications, they really could have improved the specification greatly to attack FLUKEs new Reference DMMs. Frank > -------- > In message <8fbd1ccb-9fa6-0c6f-7c7f-65a98b029922@freenet.de>, Frank Stellmach w > rites: > >> Therefore, all specifications and manuals are identical.. a pity.. >> it was hoped for, that the specifications would be improved. > How or what did you expect them to improve ? > > Improving the long term stability of the voltage and ohm references > would be nice, but either one would increase the price by 10% or so, > because we would be into "buy ten throw 9 away" territory. > > Anything else which could deliver relevant improvements gets to be > complicated and expensive: > > Battery power + optical interface could *possibly* reduce the noise > a little bit. > > A custom input connector could *possibly* reduce thermal sensitivity. > > External clock input *could* allow you to do synchronized sampling. > > And yeah, you could change the interface to be SCPI, breaking all > softwre ever written for that model... > > So all in all: I would hate to be pointed at and told "make a better one". >

PK

Poul-Henning Kamp

Sat, Oct 26, 2019 4:33 PM

In message 55e8f906-8ccf-4b78-4779-cb086ff5601c@freenet.de, Frank Stellmach w
rites:

But with those few small modifications, they really could have improved
the specification greatly to attack FLUKEs new Reference DMMs.

Well, one possibility is that they are still busy re-certifying and
the updated specs will arrive when they are ready.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

-------- In message <55e8f906-8ccf-4b78-4779-cb086ff5601c@freenet.de>, Frank Stellmach w rites: >But with those few small modifications, they really could have improved >the specification greatly to attack FLUKEs new Reference DMMs. Well, one possibility is that they are still busy re-certifying and the updated specs will arrive when they are ready. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.

DD

Dr. David Kirkby

Sat, Oct 26, 2019 5:07 PM

On Sat, 26 Oct 2019 at 17:34, Poul-Henning Kamp phk@phk.freebsd.dk wrote:

In message 55e8f906-8ccf-4b78-4779-cb086ff5601c@freenet.de, Frank
Stellmach w
rites:

But with those few small modifications, they really could have improved
the specification greatly to attack FLUKEs new Reference DMMs.

Well, one possibility is that they are still busy re-certifying and
the updated specs will arrive when they are ready.

They might want to sell off the white ones first, before releasing the
black ones.

--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892
https://www.kirkbymicrowave.co.uk/
Tel 01621-680100 / +44 1621-680100

On Sat, 26 Oct 2019 at 17:34, Poul-Henning Kamp <phk@phk.freebsd.dk> wrote: > -------- > In message <55e8f906-8ccf-4b78-4779-cb086ff5601c@freenet.de>, Frank > Stellmach w > rites: > > >But with those few small modifications, they really could have improved > >the specification greatly to attack FLUKEs new Reference DMMs. > > Well, one possibility is that they are still busy re-certifying and > the updated specs will arrive when they are ready. > They might want to sell off the white ones first, before releasing the black ones. -- Dr David Kirkby Ph.D C.Eng MIET Kirkby Microwave Ltd Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD, Essex, CM3 6DT, United Kingdom. Registered in England and Wales as company number 08914892 https://www.kirkbymicrowave.co.uk/ Tel 01621-680100 / +44 1621-680100

TK

Tom Knox

Sat, Oct 26, 2019 5:38 PM

Interesting, I wonder if this is the new 3458 I have been hearing about this past year, if so I am disappointed.
It is still the same 1988 design basically unchanged, same user interface, no digital sampling for AC measurements, and no ability to data log or other basic function offered by most recent lower performance 6.5 - 7.5 digit meter.
But I guess there is no reason to argue with success, and that said hopefully this redesign results in big gains regarding consistency between individual units, Most units since their introduction in 1988 still meet spec, but there are some that a much much better then others. I have several "Golden" 3458A's that greatly exceed drift and linearity specs and are at least a magnitude more stable the my new Fluke 8588A. If they could achieve that "Golden" performance in all their production it would be truly amazing. I actually had the original 3458A at one point, serial number proto. Up until recent years the photos in the service manual had little tape stickers identifying each board and the unit I have had those hand placed sticker exactly the same places the manual photos, the point being this unit still passed cal when I sold it about a decade ago. I wonder if one of you fellow Volt-Nut has that unit today and if it still makes spec?
Enjoy;

Tom Knox

303-554-0307

actast@hotmail.com

"Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein

From: volt-nuts volt-nuts-bounces@lists.febo.com on behalf of Poul-Henning Kamp phk@phk.freebsd.dk
Sent: Saturday, October 26, 2019 10:33 AM
To: Frank Stellmach frank.stellmach@freenet.de
Cc: volt-nuts@lists.febo.com volt-nuts@lists.febo.com
Subject: Re: [volt-nuts] HP3458A - Black Edition

In message 55e8f906-8ccf-4b78-4779-cb086ff5601c@freenet.de, Frank Stellmach w
rites:

But with those few small modifications, they really could have improved
the specification greatly to attack FLUKEs new Reference DMMs.

Well, one possibility is that they are still busy re-certifying and
the updated specs will arrive when they are ready.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.

Interesting, I wonder if this is the new 3458 I have been hearing about this past year, if so I am disappointed. It is still the same 1988 design basically unchanged, same user interface, no digital sampling for AC measurements, and no ability to data log or other basic function offered by most recent lower performance 6.5 - 7.5 digit meter. But I guess there is no reason to argue with success, and that said hopefully this redesign results in big gains regarding consistency between individual units, Most units since their introduction in 1988 still meet spec, but there are some that a much much better then others. I have several "Golden" 3458A's that greatly exceed drift and linearity specs and are at least a magnitude more stable the my new Fluke 8588A. If they could achieve that "Golden" performance in all their production it would be truly amazing. I actually had the original 3458A at one point, serial number proto. Up until recent years the photos in the service manual had little tape stickers identifying each board and the unit I have had those hand placed sticker exactly the same places the manual photos, the point being this unit still passed cal when I sold it about a decade ago. I wonder if one of you fellow Volt-Nut has that unit today and if it still makes spec? Enjoy; Tom Knox 303-554-0307 actast@hotmail.com "Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein ________________________________ From: volt-nuts <volt-nuts-bounces@lists.febo.com> on behalf of Poul-Henning Kamp <phk@phk.freebsd.dk> Sent: Saturday, October 26, 2019 10:33 AM To: Frank Stellmach <frank.stellmach@freenet.de> Cc: volt-nuts@lists.febo.com <volt-nuts@lists.febo.com> Subject: Re: [volt-nuts] HP3458A - Black Edition -------- In message <55e8f906-8ccf-4b78-4779-cb086ff5601c@freenet.de>, Frank Stellmach w rites: >But with those few small modifications, they really could have improved >the specification greatly to attack FLUKEs new Reference DMMs. Well, one possibility is that they are still busy re-certifying and the updated specs will arrive when they are ready. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ volt-nuts mailing list -- volt-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com and follow the instructions there.

BB

Bob Bownes

Sat, Oct 26, 2019 5:48 PM

New RoHS regulations probably render that impossible. We’re having that problem with some inventory at $DAYJOB.

Though I’m sure the volt nut community would be happy to accept a donation of the remaining inventory before the deadline. ;)

On Oct 26, 2019, at 13:07, Dr. David Kirkby drkirkby@kirkbymicrowave.co.uk wrote:

On Sat, 26 Oct 2019 at 17:34, Poul-Henning Kamp phk@phk.freebsd.dk wrote:

In message 55e8f906-8ccf-4b78-4779-cb086ff5601c@freenet.de, Frank
Stellmach w
rites:

But with those few small modifications, they really could have improved
the specification greatly to attack FLUKEs new Reference DMMs.

Well, one possibility is that they are still busy re-certifying and
the updated specs will arrive when they are ready.

They might want to sell off the white ones first, before releasing the
black ones.

--
Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD,
Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892
https://www.kirkbymicrowave.co.uk/
Tel 01621-680100 / +44 1621-680100

volt-nuts mailing list -- volt-nuts@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com
and follow the instructions there.

New RoHS regulations probably render that impossible. We’re having that problem with some inventory at $DAYJOB. Though I’m sure the volt nut community would be happy to accept a donation of the remaining inventory before the deadline. ;) > On Oct 26, 2019, at 13:07, Dr. David Kirkby <drkirkby@kirkbymicrowave.co.uk> wrote: > >> On Sat, 26 Oct 2019 at 17:34, Poul-Henning Kamp <phk@phk.freebsd.dk> wrote: >> >> -------- >> In message <55e8f906-8ccf-4b78-4779-cb086ff5601c@freenet.de>, Frank >> Stellmach w >> rites: >> >>> But with those few small modifications, they really could have improved >>> the specification greatly to attack FLUKEs new Reference DMMs. >> >> Well, one possibility is that they are still busy re-certifying and >> the updated specs will arrive when they are ready. >> > > They might want to sell off the white ones first, before releasing the > black ones. > > > -- > Dr David Kirkby Ph.D C.Eng MIET > Kirkby Microwave Ltd > Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD, > Essex, CM3 6DT, United Kingdom. > Registered in England and Wales as company number 08914892 > https://www.kirkbymicrowave.co.uk/ > Tel 01621-680100 / +44 1621-680100 > _______________________________________________ > volt-nuts mailing list -- volt-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > and follow the instructions there.

TK

Tom Knox

Sat, Oct 26, 2019 5:53 PM

Interesting you mention the external clock, co-workers actually built a daughter board that replaced the 20MHz oscillator on the A/D board with one that allowed a external 10MHz reference, it noticeably helped with AC measurements. I have no say, but will ask if there is any chance I can share this upgrade with interested members of the Time-Nuts community..
Cheers;

Tom Knox

303-554-0307

actast@hotmail.com

"Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein

From: volt-nuts volt-nuts-bounces@lists.febo.com on behalf of Poul-Henning Kamp phk@phk.freebsd.dk
Sent: Saturday, October 26, 2019 7:56 AM
To: Discussion of precise voltage measurement volt-nuts@lists.febo.com; Frank Stellmach frank.stellmach@freenet.de
Subject: Re: [volt-nuts] HP3458A - Black Edition