EU3458A - what appears to be a 3458A for sales in the European Union only
Hello David,
the 3458A is not offered any more by the usual distributors here in
Germany, like datatec or Meilhouse.
That's due to EU:RoHS directive , i.e. leadfree soldering is required,
and the last exemption for 'measuring and displaying devices' ran out as
of July 2017.
So KS found a way to export that lead containg 3458A directly from the
U.S., but I do not remember the special judicial trick for that... only
that this very same instrument is now called EU3458A.
KS up to now had no chance at all to redesign this instrument to
lead-free, because many special components were either terminated
already, or were custom specific parts, which never had an updated
lead-free equivalent, or were through-hole components with no proper SMD
variant. Just look at that badly designed LTZ1000A reference inside the
34470A, that's nearly a 1:1 copy, but with lower-grade SMD chip
resistors, instead of the original Vishay bmf through-hole ones.
Other examples are the fast comparators EL2018, the A/D hybrid, probably
many of the FETs, and the TaN resistor arrays.
Btw.: In the schematics, sheet 2/5 of the analogue board, current
shunts, there is a strange series arrangement of 'blind' vias.
These solder joints probably serve as thermocouple balancing for the
current resistors, to achieve low thermal voltages.
That's not so easy to be replaced in lead-free technology, either.
The only board agilent did redesign, very probably lead-free, and in a
compatible / plug-in replacement manner, was the µP board.
Up to then, it was easy to buy and insert four 62256 SRAMs and get the
01 option for maybe 30€.
I've done that directly in 1989, for my first 3458A @ university, later
in 2009 for my own hp3458A (2001 vintage), and these RAMs are still
available today, if you have an elder unit.
The new µP board has the memory inside the new ASIC, and that has to be
enabled by a 8 pin IC, maybe a PAL or such.
For the sake of tradition, KS still takes a lot of money for that
option, but you might order this PAL for about 30$, if I remember right,
and get this option for a reasonable price.. but that's not 'official',
and maybe KS meanwhile has shut down this loophole.
Please visit TiNs exceptional website (xdevs.com) for further details
Frank
In message 7862525b-4879-0c7c-c13a-9a6c1f4a3523@freenet.de, "Dr. Frank" write
s:
Up to then, it was easy to buy and insert four 62256 SRAMs and get the
01 option for maybe 30€.
I've done that directly in 1989, for my first 3458A @ university, later
in 2009 for my own hp3458A (2001 vintage), and these RAMs are still
available today, if you have an elder unit.
And now comes the pointed question:
How many of you have actually ever used that extra memory ?
As far as I can tell, most people simply want to check as many
"Opt" boxes as possible, just on general collectors principle,
they never actually use the extra memory for anything.
So please spare me the tears over KeySight charging money to cover
their costs and make some profit on that PAL chip...
--
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 7862525b-4879-0c7c-c13a-9a6c1f4a3523@freenet.de, "Dr. Frank" write
s:
Up to then, it was easy to buy and insert four 62256 SRAMs and get the
01 option for maybe 30€.
I've done that directly in 1989, for my first 3458A @ university, later
in 2009 for my own hp3458A (2001 vintage), and these RAMs are still
available today, if you have an elder unit.
And now comes the pointed question:
How many of you have actually ever used that extra memory ?
As far as I can tell, most people simply want to check as many
"Opt" boxes as possible, just on general collectors principle,
they never actually use the extra memory for anything.
So please spare me the tears over KeySight charging money to cover
their costs and make some profit on that PAL chip...
Poul-Henning,
that's a really good remark ..a nyhow I needed that in 1989 at first,
when I used the 3458A for digitizing @ 100kHz / 16bit, at first for
capturing 256 sine wave periods from my AC susceptometer.
Later, I wrote some DMA code to continuosly transfer the data directly
into the sizzling fast 20MHz AT-PC...
And just recently, I needed that memory again, to digitize the initial
drift of a precision 1kV :10V divider .. as the direct fast transfer
would have required special code again.
Same story for the 34465A, the digitizing option is useless w/o the 2MB
memory option, because the operational system of the DMM is too slow to
transfer the 32bit or floating point data directly over the busses,
although KS claimed it would be completely compatible to the 34411A
(which has in fact 16bit transfer also).
So, no crocodile tears necessary, sometimes you really need these
collectors options.
Frank
Am Tue, 15 May 2018 15:08:54 +0200
schrieb "Dr. Frank" frank.stellmach@freenet.de:
Hello David,
the 3458A is not offered any more by the usual distributors here in
Germany, like datatec or Meilhouse.
That's due to EU:RoHS directive , i.e. leadfree soldering is
required, and the last exemption for 'measuring and displaying
devices' ran out as of July 2017.
So KS found a way to export that lead containg 3458A directly from
the U.S., but I do not remember the special judicial trick for
that... only that this very same instrument is now called EU3458A.
In the meantime I got to know what kind of trick that is: Keysight
Germany imported a few hundred units into the EU just before the last
exemption ran out. Those have been put on shelves and are now sold as
EU3458A (basic unit) or EU3458AX (including options 001 and 002). So
they're not lead-free at all, it just happens that - and this is
my personal interpretation - legally Keysight Germany is reselling
units that have been bought and shipped from Keysight Headquarters into
the EU before the final deadline.
KS up to now had no chance at all to redesign this instrument to
lead-free, because many special components were either terminated
already, or were custom specific parts, which never had an updated
lead-free equivalent, or were through-hole components with no proper
SMD variant. Just look at that badly designed LTZ1000A reference
inside the 34470A, that's nearly a 1:1 copy, but with lower-grade SMD
chip resistors, instead of the original Vishay bmf through-hole ones.
Other examples are the fast comparators EL2018, the A/D hybrid,
probably many of the FETs, and the TaN resistor arrays.
Non-availability of special components, especially non-existence of
lead-free and/or through-hole variants is nothing that would actuallly
stop Keysight, or any other major manufacturer from updating their
equipment. After all, if they already employ custom parts, nobody is
stopping them from packaging in a way that would make them
RoHS-compliant. It would be a very obscure manufacturing process that
actually has the banned substances in the silicon, so custom packaging
would most likely solve that issue. Also the other things mentioned are
not unsolvable. Parts are becoming unobtanium? In nearly every case
that can be solved. Products and manufacturing processes can be
transferred, and there are fabs willing to do exactly that, and not all
of them stop talking to you if you don't ask for thousands of wafers a
month.
Besides, they (that is, Keysight and competitors) do have the
capabilities to do full custom asics if needed. It's much more likely
that they don't see sufficient market demand to justify doing that.
In the end it's not so many people that actually need 6 digits or more.
Best regards,
Florian