Re: [volt-nuts] EU3458A - what appears to be a 3458A for sales in the European Union only

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 p...@free

Re: [volt-nuts] Does desoldering and resoldering an LTZ1000A reset the ageing?

In message , "Dr. David Kirkby" writes: >Does anyone know if desoldering one and resoldering resets the aging >process? I don't think it "resets" as such, but it certainly starts some kind of aging process, as does hard knocks, thermal shocks, vibrati

Re: [volt-nuts] Low noise reference

a couple of the cheapest "teflon" capactors from the audiohomøopathy world, and see if that is really what it claims to be. Poul-Henning [1] I've been told that the liquid used in dishwashers to avoid spots on glass, a mixture of soaps and alcohols, is also good for electronics,

Re: [volt-nuts] List contents of user NVRAM in 3458A?

? will tell you pretty useless stuff about memory split But I don't recall there being a command to list the names of the stored stuff... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] 3458A question

nd after running an >ACAL 0, I get a DCV reading of -200 to -400nV (0.00040mV). > >Is that normal? I see the same kind of numbers. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] 3458A drift checking question

need it to be precise next day. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. ___

Re: [volt-nuts] 3458A question

mount the short, then hang a piece of cloth over the terminals and wait about 15-30 minutes before I run ACAL 0 -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice

Re: [volt-nuts] GPIB Issue with 3458A

h life, and they can fail or go frail in so many weird ways that it is not even funny any longer. The bad thing is that the problem may not even be the buffer chip in the instrument you are talking to :-( -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP si

Re: [volt-nuts] GPIB Issue with 3458A

In message , Randy Evans writes: >Any ideas on what might be causing the strange behavior? 1. Bad cables. 2. Sick-ish IEE488 drivers in one of the instruments or the controller Which software versions are the two HP3458 ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.2

Re: [volt-nuts] 3458A NVRAM

contents during desoldering. See the function "nvram" here for details: https://github.com/bsdphk/pylt/blob/master/hp3458a.py -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] Agilent 3458A Issues

s the problem. 209 means that the compiled in limit on one of all the many calibration values is out of range. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice wha

Re: [volt-nuts] HP-3458A NVRAM

to >the second set of DS1230Y NVRAMs? Did you change those out to DS1230AD >NVRAMS also? The second set of NVRAMs are not nearly as important as the CALRAM, they merely store the "user-ram" you can access via GPIB. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freeb

Re: [volt-nuts] HP-3458A NVRAM

k that difference will make any difference. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explaine

Re: [volt-nuts] Power consumption of 3458A reference board / fitting one in a 3457A

In message , Tom Knox writes: Don't forget that the voltage reference is only half of the magic in the 3458A. You would also need to keep the 40K reference resistor comfy. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 Fr

Re: [volt-nuts] Best way to measure micro Ohms

esome to no end. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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

Re: [volt-nuts] PCBs with ceramic substrates

ossible desirable properties are most beneficial ? The real question is if the mobile devices have brought the volume up so that running small series for specialty use is affordable? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer

Re: [volt-nuts] PCBs with ceramic substrates

g "ceramics made of metals". -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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.

Re: [volt-nuts] PCBs with ceramic substrates

>higher thermal conductivity, lower thermal expansion (AlN is >even pretty close to Si). So, why then does it hardly ever get >mentioned? Is it the cost of those? Or is there something I am >missing? I would worry about piezoelectricity ? Also, most ceramics have hideous thermal expan

Re: [volt-nuts] Basic question concerning voltage references

n a 10V signal will always be at least ± 5 microvolts. If you do the same math for a true 8½ digit DVM, you need a 29 bit A/D converter (2^28 = 268435456 + sign) which means you can use 40 nV as stepsize yielding 10.73V range, and thus in teory get ± 40nV measurements. -- Poul-Henning Kam

Re: [volt-nuts] correlate volt meters for more accurate readings

in noise. If you can, also record a representative room temperature, plot that on one axis and the two meter readings on the other, then think creatively about the result... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD

Re: [volt-nuts] Availability of 3458A in Europe after the end of 2016.

representation of its effect. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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.

Re: [volt-nuts] Availability of 3458A in Europe after the end of 2016.

ll the HP3458's they want to metrology labs etc, but they cannot "sell it retail to anybody". -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attrib

Re: [volt-nuts] How to keep voltage stable in the sub-100nV range?

this a part of the audiophoolery community? Yes, they are very much in demand for audiohomoepathy, up to the point where people actually roll their own. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-ta

Re: [volt-nuts] How to keep voltage stable in the sub-100nV range?

0 capacitors were much worse >than polypropylene film which was itself was much better than >polyester. We should add that there is a LOT of good wisdom about a lot of relevant electronic details in r3 of Art of Electronics. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd

Re: [volt-nuts] How to keep voltage stable in the sub-100nV range?

endations/suggestions what to use? > >Polypropylene? PTFE? Wet Tantalum capacitors (extreme expensive)? Mica or Teflon -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to

Re: [volt-nuts] How to keep voltage stable in the sub-100nV range?

output voltage). You can speed it up a LOT by intentionally overshooting the DAC for a short period, provided you have very carefully calibrated the time constants of the LP filters after it. BTW: A good place to get some inspiration is the HP3245A service manual. -- Poul-Henning Kamp | U

Re: [volt-nuts] How to keep voltage stable in the sub-100nV range?

in of opamps and low pass filters feeds >it to the consuming device. The absolute value and drift over more >than 10-100s is not that important. What range of voltages are we talking about ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 95

Re: [volt-nuts] low emf solder

0 computer in datamuseum.dk and also the people who designed and built the computer. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attr

Re: [volt-nuts] low emf solder

logs.sciencemag.org/pipeline/archives/2013/05/08/things_i_wont_work_with_dimethylcadmium -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explai

Re: [volt-nuts] Is there a "standard" much better than a LTZ1000, but much cheaper than a Josephson Junction Array?

their own feed of devices from Linear. Nobody outside Linear and Fluke knows what is special about them. >> 2. Lots of LTZ1000's to get sqrt(N) reductions. >It seems to me >that you would not gain sqrt(N) unless N is quite small. How small, is >anyone's guess. N=4 is commonly

Re: [volt-nuts] Is there a "standard" much better than a LTZ1000, but much cheaper than a Josephson Junction Array?

cost of a Josephson >Junction Array. A sort of half-way house. As far as I know there are only two steps between the LTZ1000 and JJAs: 1. Specially cared for LTZ1000's (See: Fluke) 2. Lots of LTZ1000's to get sqrt(N) reductions. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.2

Re: [volt-nuts] Low-cost Josephson Junction Array

In message , Ken Peek writes: >Where in the world do I *get* one of these things? How much does it cost? I belive NIST is still the major manufacturer in the market. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 Free

Re: [volt-nuts] Trump Does The Unthinkable

In message , John Phillips writes: >*Subject:* *Trump Does The Unthinkable* Even I, from my vantage point in Denmark, can see that this is pure spin with no relation to actual facts. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since

Re: [volt-nuts] Calibration of 34401A

the calibration procedure, and it is all software. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained

Re: [volt-nuts] fluke 731b battery pack

charging parameters, both NiCd and NiMH change properties rapidly above approx 40C/100F. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by

Re: [volt-nuts] Practical power supply noise testing

In message <5776e31d.7090...@pacific.net>, Brooke Clarke writes: >Instead of headphones something like the HP 4395A [...] Well, there is a slight difference in price there, isn't there ? :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org

Re: [volt-nuts] Practical power supply noise testing

t;Can someone suggest a practical test regime to verify power supply >DC noise performance? Preferably one that doesn't require building >up custom low noise amps? Listen to them ? All the "hard" noise is in the audio-range, so a series capacitor a low-noise amp and a pa

Re: [volt-nuts] LTZ1000 project build

2 and 3 decades, >and even if there are some small leaks, or a vent hole to equalize >pressure, the silica gel has still been fully dry. Only thing to remember is that it also reduces air circulation in the box and therefore increases thermal gradients. -- Poul-Henning Kamp | UNIX

Re: [volt-nuts] Solartron 7081 randomly re-initialises

In message <001501d19632$743ab230$5cb01690$@perdrix.co.uk>, "David C. Partridge " writes: >Does anyone have any thoughts as to likely faults that would cause this? EPROMs loosing bits is a good candidate. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.

Re: [volt-nuts] 3457A - should I preserve SRAM contents, or purposely corrupt them by removing power?

nt. But a good first shot: Try sending the command "MREAD 0" and see what happens... And it's not like disassembling the firmware of instruments of this vintage is a big deal anyway... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since R

Re: [volt-nuts] 3457A - should I preserve SRAM contents, or purposely corrupt them by removing power?

re doing that, so that I could compare it to whatever I got back from calibration. My experience so far says that there probably is a GPIB command which can read out the memory, but of course you still need to know the address-space layout. -- Poul-Henning Kamp | UNIX since Zilog Ze

Re: [volt-nuts] Fall of SRAM voltage in a 3457A without external power

irly good chance the contents would >remain in RAM if one was reasonably quick, especially if you topped the >voltage up from the mains just before removing it from the chassis. I usually hook up a separate battery while doing such surgery. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.2

Re: [volt-nuts] Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter

w.cryptomuseum.com/spy/fs5000/files/TC5564.pdf That looks like vanilla CMOS RAM, and it has a wide range of retention VCC, so you should be fine. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter

eshold is above the battery voltage. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. ___

Re: [volt-nuts] Wanted - UK source of a replacement battery (type LX 1634) for HP 3457A 6.5 digit multimeter

Googling around My guess is that this is a 3.6V Lithium-Thionyl battery, and if it is only 3.03V now, you're very likely tethering right on the brink. The most reputable vendor in this space is Tadiran, and they charge accordingly. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20

Re: [volt-nuts] keeping water out of enclosures (was: Low-cost voltage reference questions)

doesn't get tipped over. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. _

Re: [volt-nuts] HP3450A Reference Peltier Chambers

In message , "Dave M" writes: >My interest is in how best to fix the components to the Peltier. Copper - it has high thermal conductivity *and* high thermal capacity. Junked electrical bus-bars are a good place to start. -- Poul-Henning Kamp | UNIX since Zilo

Re: [volt-nuts] HP3450A Reference Peltier Chambers

will be. One complication is the difference in directional efficiency: The warm side receives about 4 times as much energy as is removed from the cold side. Unless you electrically compensate for this, your PID will be *really* confused. -- Poul-Henning Kamp | UNIX since Zilog

Re: [volt-nuts] LM399 newbie - questions

For audio purposes, you should pay a lot of attention to the noise the LM399 generate. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be

Re: [volt-nuts] Making a Reference IC

In message , "Dr. David Kirkby (Kirkby Microwave Ltd)" writes: >A used 3458A fetches several thousand USD, There's actually one in france for EUR1500 right now... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP sin

[volt-nuts] Voltage Modified Allan Variance

I have come clean: http://phk.freebsd.dk/hacks/HP5065A/20150822_mvar/index.html Sometimes I run voltages through the Modified Allan Variance, and it turns out to be very informative. Please, somebody with more time than me, take this idea and run with it... -- Poul-Henning Kamp

Re: [volt-nuts] Building a high resolution DAC

ssible. >But yes.. it might not be possible. I don't think it is. The necessary voltage reference will set you back almost that much... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] Building a high resolution DAC

your DAC(-lings) into a row again. I have not tried this yet myself, but once I get down through my pile of more important projects, but I'll be happy to lend any assistance I can to the project. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP si

Re: [volt-nuts] 3458A Zero reading

on radius) It is not always obvious which behaviour is preferable. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by inc

Re: [volt-nuts] HP-3458A Zero Reading

may want to try to shade the terminals from air-movement when you work in that range, thermal sensitivity is not negligble. I had better luck using relatively thick (1.5mm^2) copper wire. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeB

Re: [volt-nuts] External Freq Reference Mod for 3458A?

lastic) optical fiber, and I think a significant clue should be taken from that: Optocouplers and transformers are unlikely to be good enough. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] 3458A resistance calibration

s to be somewhat tighter. I've always wondered what a company like HP did with rejects against in-house-specs ? Did they have multiple grades so that the best ended up in 3458, the next best in 3457 and the ones living up to manufactureres spec in 3456 ? -- Poul-Henning Kamp |

Re: [volt-nuts] "*WAY* too expensive for even Keysight to redesign"

mostly in K&R style C, using IEEE floating point so porting it to another chip is not a big deal. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can

Re: [volt-nuts] "*WAY* too expensive for even Keysight to redesign"

rwise the analog part will be of no use to you. Not even the EU's "interop" rule wills save you in this case, as you cut into the middle of a product. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer

Re: [volt-nuts] "*WAY* too expensive for even Keysight to redesign"

In message , John Phillips writes: >I would think that a lot of the patents would be running out soon as if >that would make any difference. I wrote "copyright", not "patent". Thanks to Disney copyright never runs out as long as a lawyer cares. -- Poul

Re: [volt-nuts] "*WAY* too expensive for even Keysight to redesign"

can (legally) do it as a commercial project. That said, there are *so* many interesting things you could do with that meter with improved software... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-ta

Re: [volt-nuts] "*WAY* too expensive for even Keysight to redesign"

r after, is how simple it is to calibrate. They like that. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be exp

Re: [volt-nuts] "*WAY* too expensive for even Keysight to redesign"

scale, production runs are never an option. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately b

Re: [volt-nuts] Transmille 8081

hrough the HP multislope in AOE3. Doesn't really go into the 3458 much, but they lay out how the subsequent versions in 34401/34972 do things. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-ta

Re: [volt-nuts] The Art of Electronics

n't call myself "new to electronics", I built my first computer in 1978 :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequatel

Re: [volt-nuts] The Art of Electronics

that not everybody here are professional electronics people, I'm a software person who knows enough electronics to be useful without being dangerous, and I've certainly learned a lot from AOE3 over breakfast this past week. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freeb

Re: [volt-nuts] The Art of Electronics

In message <20150417074427.ga31...@sol.ermione.com>, Andrea Baldoni writes: >Hello. >In the case someone missed the new, after years of waiting, the third edition >of the book in the subject is out! I received it last week, and yes, it's absolutely worth the money

Re: [volt-nuts] dark display for 3458

prints a blank string. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. ___

Re: [volt-nuts] dark display for 3458

7;s just faster for pixels turned on. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. _

Re: [volt-nuts] 3458a BASIC commands for today???

In message <54e5506b.3020...@williams-net.com>, new writes: >Can any of the BASIC programs found in the manuals be used nowdays? If you are willing to consider something more modern than BASIC: https://github.com/bsdphk/pylt -- Poul-Henning Kamp | UNIX since Z

Re: [volt-nuts] plastic caps on 3458A reference board

p;products_id=89 I'm pretty sure you'd get very stable temperatures, my worry is that you'd get too high stable temperatures... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] HP3458A cal ram data dumper

In message , Joseph Gray writes: >Would this work on a 3457A by any chance? It only works on HP3458A. The HP3457A has an entirely different (CPU) architecture, but it is advanced enough that a similar trick may be possible. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.2

Re: [volt-nuts] The "averaging reference"

hem different weight depending on their qualities. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. ___

Re: [volt-nuts] Agilent 34970A (34401A) self test error 606

s about the HP3458A is useful. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. _

Re: [volt-nuts] Voltage Reference.

In message <5454c970.40...@t-online.de>, Andreas Jahn writes: >Further Peltiers have one disadvantage that I do not want to have in >precision cirquits: >The cold side is always collecting humidity. Only if you cool below the dewpoint. -- Poul-Henning Kamp | U

Re: [volt-nuts] Voltage Reference.

you just want to stabilize the temperature around ambient, you need very little power to a peltier to do that, and it can move heat both ways. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] 732A rear panel battery connector

somewhat simpler: Just a 24/24 isolated DC/DC converter (for isolation obviously), no need for an extra set of batteries in my case. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never

Re: [volt-nuts] 732A rear panel battery connector

I have a 732A without the battery plugin, and I already have a standby 24V supply in my lab. Has anybody tried to create the needed bits in the middle of that combination before ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956

Re: [volt-nuts] Old HP3458A - SN: 2823A 03939

>adrian in general I'd agree, for the HP3458A not so much: The two internal references are incredibly stable over long periods of time. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] Old HP3458A - SN: 2823A 03939

but I don't have access to the '2' version, so I don't know what the difference might be. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe

Re: [volt-nuts] Finally got around to modifying my Fluke 845ab with LED's

Notice that many white leds are specifically engineered to have long persistence, so that they can be driven directly from 50/60 Hz without flicker. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD

Re: [volt-nuts] 732A and Prologix received

In message , Stan Katz writes: *real* metrology purists keep their instruments in a pre helium atmosphere to improve cooling, prevent corrosion and stop people from breathning on things :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since

Re: [volt-nuts] AC calibration

oul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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 -- v

Re: [volt-nuts] Looking for Datron 4000 series calibration key!

In message , Todd Micallef writes: Please notice that when you read the HP3458A over GPIB you get a slightly higher precision due to more decimals being presented, than you do on the display. If you are measuring down near the noise-limit, this matters. -- Poul-Henning Kamp

Re: [volt-nuts] HP3458A CAL ram data dumper program

faces), copy my >> HP3458.EXE program to the GPIBKIT directory and run it. Check the comments >> at the start of HP3458.CPP for some info. Run HP3458.EXE without any >> command line arguments for program usage help. >> >> >Anybody, perchance, have any goodies like

Re: [volt-nuts] New HP3458A

; on the net. There is no relevant difference between REV 9 and REV 8 worth opening the box for. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adeq

Re: [volt-nuts] HP3458A calibration memory backup

erial number) it is >always FF. I belive that depends on what happened previously on the data-bus of the M68K cpu. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to

Re: [volt-nuts] 3458 memory and communications

MREAD 393220 ... MREAD 397308 MREAD 397310 and save the results. But that's 2048 MREAD commands, so having a program to do it would be a lot easier... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956

Re: [volt-nuts] HP3458A calibration memory backup

___p 000607d0 > 7f 01 00 00 00 00 00 00 00 00 00 44 f4 a4 -- -- D __ 000607de .fill 0xa0 [0x21] -- -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer

Re: [volt-nuts] HP3458A calibration memory backup

t was 05. I didn't write >down what it was the other time. As far as I know, that is an unused area of the CALRAM, so the difference could seem to indicate that your CALRAM battery is on its last legs... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org |

Re: [volt-nuts] HP3458A calibration memory backup

n try to see if that bit matters. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. _

Re: [volt-nuts] Latching Low Thermal EMF Relays

g registers. Therefore they went back to the old "holding coil" model instead. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be expl

Re: [volt-nuts] AC Voltage Measurement Standards

Thermal converters measure the heating caused by the electric energy as a temperature increase over ambient temperature. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice

Re: [volt-nuts] 732b transformer replacement

common failure modes is a break right next to the solder-lug. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be e

Re: [volt-nuts] volt-nuts Digest, Vol 56, Issue 9

doing a switch both "up" and "down" but of different lengths to get the desired result. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequ

Re: [volt-nuts] 34401A Why 10M ohm default i/p resistance?

l is specifically about how the input circuit is designed for use also in sampling AC measurements and digitizer applications. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attri

Re: [volt-nuts] 34401A Why 10M ohm default i/p resistance?

input resistance caused by changing ranges) from affecting the > measurements. Please don't forget that the 3458A is not just an 8.5 digit metrological wonder, it is also a precision 16 bit 100 ksample/s digitizer. Many of the attributes of the input circuit are not there for voltage

Re: [volt-nuts] 34401A Why 10M ohm default i/p resistance?

the 3458A manuals. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@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. ___ vo

Re: [volt-nuts] 34401A Why 10M ohm default i/p resistance?

e compatibility reasons others have mentioned, it also protects the input circuits against random elctrostatic fluctuations if nothing is attached, and it delays things just long enough that if you attach +100V, it doesn't have to wait for a relay to kick in before autorange can work. -

Re: [volt-nuts] 3458a with 202: Slave Test Convergence (sigh)

ng extra SRAM chips, but unless you have ever run out of memory it is not going to make any difference. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can

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