hybridfree/eevblog-posts huggingface dataset:
Fluke 5440B GPIB problem [solved] - Page 1
Forum section: electronics / general

author: e61_phil
author_rank: Frequent Contributor
timestamp: January 26, 2017, 09:00:44 pm
content: Hi,today I wanted to connect my Fluke 5440B to my GPIB "network", but I had some problems. First of all: If I connect the Fluke 5440B to my GPIB chain the VISA stuff will find instruments starting from the Fluke 5440B GPIB adresse. (if it is configured to 20 then 20, 21,..., 30 will appear in NI MAX). All other GPIB devices will work without distortions.Then I tried to send some commands to the 5440B. However, the 5440B shows "IEEE488 REMOTE ERROR EXPECTING HEADER" and nothing happens. The same commands will work in the company with the Fluke 5440B from the company. The difference between here and there is the GPIB adaptor. I'm using a NI PCI GPIB card and at the company we have some NI USB dongles. But I doubt that is the problem.I already read the manual twice and split my GPIB bus to reduce cable length. But nothing works. Is there something broken on my 5440B or is there something I overlook?ThanksPhilipp

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: January 26, 2017, 10:00:08 pm
content: I have had problems with older gear not talking to a controller. My Keithley 181 was very problematic. I think if the commands you are sending are identical, then I would look at termination characters. The 5440B manual states it only accepts ASCII(10) or ASCII(13) and the other special characters are dropped. There may be some being added automatically.Start with different combinations of those two to see if that makes a difference. Usually these manuals have programming examples with the HP 85a computer but I didn't see anything in the digital versions. I can look at my originals and see if there is anything. Also, the 5440A may have some clues.

author: e61_phil
author_rank: Frequent Contributor
timestamp: January 26, 2017, 10:06:24 pm
content: Thanks for your hints.My Keithley 619 was also very problematic, but it works. And a Fluke 5450A is also working. I think the Fluke 5450A is from the same era.I already tried to append \n \r in all combinations, but it doesn't work. The Fluke 5440B in the company shows error messages without \n, but it executes the commands anyhow.

author: e61_phil
author_rank: Frequent Contributor
timestamp: January 26, 2017, 11:27:15 pm
content: There was something broken..I replaced the bus buffers (U17 & U19) and know it works.
Metrology - PPM standards, are there any? - Page 1
Forum section: electronics / general

author: cncjerry
author_rank: Unknown
timestamp: January 22, 2017, 03:47:30 am
content: I've been messing with standards lately and was wondering if there are ratings for PPM in terms of degrees C/F over time? So for instance, if I have a voltage standard that drifts 1 PPM +/- over say 4 hours vs another that drifts 5 PMM over the same time then we know which is better but are they both within the same rating level? Just curious if there are standards. A, B, C, class 1, class 2, etc?And if so, what about in terms of noise in PPM?Thanks

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: January 23, 2017, 08:37:12 pm
content: Lots of views, no replies, so I'll give it a go. I bet you're thinking about pin gage standards and such for the shop, like a class ZZ pin. Basic answer, AFAIK, is no. Manufacturers state whatever specs they want, and even comparing one thing to another can be tricky. Same with noise.

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: January 23, 2017, 09:09:22 pm
content: I would agree with Conrad - I have never, ever seen any sort of unified tolerance level specification on lab measures of things like a voltage reference. If a precision voltage tolerance is specified, you also need to specify what noise level, at what bandwidth, at what current flow, at what Temperature Coefficient, at what drift rate, at what uncertainty of measurement, and at what percentage confidence, at what MTBF, and so on. You could fill a book on deciding what parameters to include or not.So it could be hard to lump all those together into something like a "Level 5" precision Voltage Reference or whatever, and have that mean anything in particular. Every application is a little different.The closest thing to what you ask is you can have an "Accredited Lab" based on NIST guidelines, and that tells you what basic capabilities a calibration lab can handle. For instance can a lab give you a measure down to 5ppm uncertainty, or down to 2ppm, etc. NIST maintains that list over at their website. The higher the accuracy measure you want from a lab, the cost goes up exponentially.

author: Andreas
author_rank: Super Contributor
timestamp: January 24, 2017, 07:32:55 pm
content: Hello,with voltage calibrators sometimes it is mentioned for 5.5, 6.5 or 8.5 digit instruments.(Fluke 5730A, Keithley 263)With best regardsAndreas
METRA Blansko resistance decade peek inside :) - Page 1
Forum section: electronics / general

author: daqq
author_rank: Super Contributor
timestamp: January 22, 2017, 06:22:58 pm
content: Hi guys,I got a new toy, an old-ish (~30 years or so) Czechoslovakian L110 resistor decade made by METRA Blansko. Since something was rattling inside, I took it apart and took a few pics.See:http://www.daqq.eu/?p=1309for full gallery and measurement results.It's funny to see a combination of technologies - wirewound for the higher resistances (x1k and x10k ranges) and the rest are done using resistive material plated onto a PCB and then etched. And hand trimmedBest regards,David

author: Vgkid
author_rank: Super Contributor
timestamp: January 22, 2017, 09:58:45 pm
content: Those (0.10, 01.0, 10.0) Ohms boards are truely fascinating. Did they use a resistive foil bonded to the pcb, or did they use plain solder trace?Surprised they didn't use the resistor arrangement(2+2+2+2+2+1) in order to free up some space, and make the board simpler.

author: SeanB
author_rank: Super Contributor
timestamp: January 22, 2017, 10:07:15 pm
content: looks like a plain SRBP board with standard copper on it. not the best stability, or the best TC, but for a resistance box where the switch likely is a large part of the decade error it works well enough.

author: daqq
author_rank: Super Contributor
timestamp: January 23, 2017, 06:43:15 am
content: To the best of my knowledge the PCB material is actually not copper, but rather resistive material that was etched away to make the basic structure and then hand trimmed.edit: Also, a copper trace of a 4mm width with the length of half a meter would still have a DC resistance of only ~0.05 Ohms, assuming 9um copper plating (calculated by Saturn PCB toolkit).
High accuracy transportable selectable - Value High Dc Voltage Standard - Page 1
Forum section: electronics / general

author: mimmus78
author_rank: Unknown
timestamp: February 07, 2017, 03:45:59 pm
content: Anyone knows more about this thingy?Maybe I ask to those guys if they want to share some more ... it seems quite interesting.http://cfmetrologie.edpsciences.org/articles/metrology/pdf/2015/01/metrology_metr2015_12007.pdf

author: CalMachine
author_rank: Frequent Contributor
timestamp: February 07, 2017, 03:50:36 pm
content: Intriguing!! I'll have to look into this.

author: wiss
author_rank: Frequent Contributor
timestamp: February 07, 2017, 04:21:40 pm
content: Battery powered fluke 341?With fewer divider-steps of course...

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: February 08, 2017, 02:54:08 pm
content: Maybe I missed it, but I don't see what the actual standard is.

author: CalMachine
author_rank: Frequent Contributor
timestamp: February 08, 2017, 03:30:29 pm
content: Quote from: Conrad Hoffman on February 08, 2017, 02:54:08 pmIf you scroll down towards the bottom of the article to the page with the picture of the test setup. I believe the standard is labeled (a) in that picture (the big silver box in the top right)

author: 2N3055
author_rank: Super Contributor
timestamp: February 08, 2017, 03:37:44 pm
content: Quote from: CalMachine on February 08, 2017, 03:30:29 pmNope, that is the THVS box, and 10V standard is in the middle, labeled (b) and looks like Fluke 723B

author: CalMachine
author_rank: Frequent Contributor
timestamp: February 08, 2017, 04:03:38 pm
content: Quote from: 2N3055 on February 08, 2017, 03:37:44 pmIf he is referring to the 10V standard, then I misunderstood his question

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: February 08, 2017, 04:37:15 pm
content: OK, now I see it- just had to blow up the picture a bit! Thanks.
PEAKTECH 2010DMM - Page 1
Forum section: electronics / general

author: lionelkjh
author_rank: Frequent Contributor
timestamp: January 12, 2017, 11:48:57 am
content: Hello; I am looking for the diagram of the multimeter PEAKTECH 2010 DMM (equipped with a card: VICTOR 88C-1 V3.0). Can anyone help meThanks in advance
Fluke 5440B long term stability - Page 1
Forum section: electronics / general

author: e61_phil
author_rank: Frequent Contributor
timestamp: January 11, 2017, 09:00:34 pm
content: Hi,I think some of the users here will have a Fluke 5440B/5442A and a Fluke 732A.The Fluke 5440B uses two SZA263 in series and the famous Fluke 732A will only have one SZA263. Therefore, my question ist: How stable is the Fluke 5440B compared to a Fluke 732A over years?If the Fluke 732A is more stable then I have to aks why?BestPhilipp
AGILENT U1733C - Page 1
Forum section: electronics / general

author: lionelkjh
author_rank: Frequent Contributor
timestamp: January 09, 2017, 11:50:36 am
content: Hello everyone! I am looking for firmware AGILENT U1733C; Somebody would have it, or could it help me to download it on the site of AGILENTThank you for you precious help
Relay contact material selection  - Page 1
Forum section: electronics / general

author: IconicPCB
author_rank: Super Contributor
timestamp: January 17, 2017, 07:22:12 am
content: Looking for a recommendation for relay contact material for minimum thermal EMF and low current performanceEither relay contact materials or perhaps relays.

author: Echo88
author_rank: Frequent Contributor
timestamp: January 17, 2017, 07:54:48 am
content: Please take a look at the following threads which answer your "which relay?"-question:https://www.eevblog.com/forum/metrology/measurements-on-emf-error-of-switches/https://www.eevblog.com/forum/metrology/metrology-grade-scanner-card/https://www.eevblog.com/forum/projects/diy-low-thermal-emf-switchscanner-for-comparisons-of-voltage-and-resistor-stand/msg610755/#msg610755https://www.eevblog.com/forum/metrology/low-thermal-emf-scanner-and-ordinary-non-latching-relays/

author: IconicPCB
author_rank: Super Contributor
timestamp: January 17, 2017, 09:18:23 am
content: A full bottle

author: IconicPCB
author_rank: Super Contributor
timestamp: January 21, 2017, 11:39:20 pm
content: Seems relay coil power dissipation is an issues.A "spike-and-hold" driver could reduce the power dissipation significantly.

author: SeanB
author_rank: Super Contributor
timestamp: January 22, 2017, 04:57:05 pm
content: Bistable relays perform best with low thermal EMF issues, but are expensive, and you will have spikes with the suddenly heats coils during actuation.

author: IconicPCB
author_rank: Super Contributor
timestamp: January 22, 2017, 09:44:46 pm
content: Spike and hold drive is intended to drive conventional relays with the view to minimising heat within the relay assembly.Spike voltage = required voltage to pull in the armaturehold voltage -= required voltage to hold the armature once relay has been actuatedhold voltage < spike voltagedissipated power reduction = proportional to difference between the squares of two voltages
MAX5719 20-Bit Voltage DACs - Page 1
Forum section: electronics / general

author: branadic
author_rank: Super Contributor
timestamp: December 12, 2016, 08:08:00 am
content: A new part is available, MAX5719. Interesting that the name is somewhat similar to AD5791.https://www.maximintegrated.com/en/products/analog/data-converters/digital-to-analog-converters/MAX5719.html

author: Echo88
author_rank: Frequent Contributor
timestamp: December 12, 2016, 11:10:06 am
content: Meh, seems to me the Max5719 is much worse specswise than the AD5791. *keeps simulating the Fluke 5720A-PWM-DAC*

author: tszaboo
author_rank: Super Contributor
timestamp: December 12, 2016, 12:00:35 pm
content: It has up to 64 LSB INL. So it is a 14 bit DAC. Also, with a DNL of +/-2 LSB, when you change the output code, the voltage *probably* will go the right way. So to say, it is not guaranteed monotonic. Might as well use a 32 (joke) bit audio DAC.

author: JoeN
author_rank: Frequent Contributor
timestamp: December 28, 2016, 07:56:26 am
content: This begs a question. Why can Analog make a part (in 2011) that guarantees 1 PPM INL and Maxim making a similar part (in 2016) can guarantee only 64 PPM INL? That is a huge difference. What does Analog know that Maxim doesn't? Can anyone else do as well? It seems to me Linear had the closest specs with 18 bit parts like LTC2756. Not sure anyone else even comes close.

author: ap
author_rank: Frequent Contributor
timestamp: December 28, 2016, 09:20:08 am
content: Maxium could probably do it as well, question always is what the target market/price/application/yield... is. It is a wrong assumption to believe a chip manufacturer always wants to do the best in designing a certain product. Sometimes they screen parts and sell better ones for higher prices; or the dont screen. The product marketing guy will decide.
UART data plotter - Page 1
Forum section: electronics / general

author: mash107
author_rank: Contributor
timestamp: December 10, 2016, 05:49:01 pm
content: Is there available a data plotter, preferably open source, that can plot numerical data on a graph (with zoom functions, similar to Labview) from a UART serial port? I'd wager it wouldn't be too difficult to create, but I'd rather not reinvent the wheel if it's out there

author: Echo88
author_rank: Frequent Contributor
timestamp: December 10, 2016, 07:26:44 pm
content: Theres for example MakerPlot:http://www.makerplot.com/introducing_makerplot.htm
Close value population removed from R or C lot - Page 1
Forum section: electronics / general

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: December 02, 2016, 06:05:02 pm
content: This is an obvious trick, unless you haven't thought of it, which took me longer than I care to admit. I had a batch of extremely good capacitors, near zero TC, but all the close tolerance parts had been removed, leaving only parts quite high and quite low from the nominal value. A double humped distribution. Then it hit me. Put a selected high and low in series to get an exact half value. Do it again. Now put the pairs in parallel to get back to the original desired value. Sure, you use 4 parts, but for standards and such it works well. For resistors, parallel a high and low, then put the pairs in series. A bag of useless becomes a bag of useful.

author: enut11
author_rank: Super Contributor
timestamp: December 02, 2016, 08:34:34 pm
content: Thanks Conrad. A very handy tip on how to make use of lower tolerance quality components.enut11
METRIX MX57EX - Page 1
Forum section: electronics / general

author: lionelkjh
author_rank: Frequent Contributor
timestamp: November 27, 2016, 02:51:08 pm
content: Hello everyone! I have a high-end Metrix mx57ex, and I also have calibration software. I do not have the link of the multimeter to the computer. I have in my possession an eeprom programmer (TL-866CS) and I was able to extract the memory (93C46). So my question is: is there a way to read from the Metrix calibration software the contents of the eeprom memory (bin file), to correct some errors in calibrating the multimeter on the 'computer?Thanks in advance for your help in this headache that I try to elucidate .....

author: lionelkjh
author_rank: Frequent Contributor
timestamp: November 29, 2016, 12:07:15 pm
content: sniff!

author: 2N3055
author_rank: Super Contributor
timestamp: November 29, 2016, 12:27:08 pm
content: My advice would be to buy/make a cable and not tamper with the imstrument...if you have cal software..

author: lionelkjh
author_rank: Frequent Contributor
timestamp: November 30, 2016, 11:43:05 am
content: Hello; thank you for your reply. How to make the cable(The original cable can not be found) ......

author: macboy
author_rank: Super Contributor
timestamp: November 30, 2016, 01:44:05 pm
content: The cable is simple to make. Refer to my old post athttps://www.eevblog.com/forum/testgear/metrix-mx56c-bk-precision-5390-multimeter-teardown/msg268678/#msg268678You need a USB UART converter ($1 to $2 on ebay etc.), plus a IR LED, an IR phototransistor, and a couple resistors. You wire the IR LED to the transmit side of the USB UART - use a series resistor of about 1k and wire the cathode to the Tx pin and anode to the +3.3 V pin. You connect the phototransistor to pull the Rx pin low when receiving (use a pull up resistor also). If you point your LED at your phototransistor, you should receive whatever you transmit on the serial line using a terminal program like putty or hyperterminal. If you block the light path, it should stop echoing. After that works you can try to talk to the meter. The simplest thing to do is press PRINT key to get a reading as ASCII text over the serial link (open the port at 2400/8/N/1). After that works you can try the software.

author: lionelkjh
author_rank: Frequent Contributor
timestamp: November 30, 2016, 06:40:31 pm
content: Good evening: thank you for this precise answer! A question still crosses my mind: Is there a universal software for all multimeters to calibrate (with the interface you mention), and how to get it
Volt-Nuts, Time-Nuts and the Laws of the Universe! - Page 1
Forum section: electronics / general

author: wn1fju
author_rank: Frequent Contributor
timestamp: November 29, 2016, 10:50:44 pm
content: Excuse me if this is a naive question, but it has been puzzling me for a while.In the arena of volts, resistance and current measurement (or generation), achieving 1 ppm accuracy (at least in a home lab situation) is far from trivial and will set you back a lot of money.Yet, achieving 1 ppm frequency accuracy is very easy (a $5 crystal with perhaps a temperature compensating capacitor), and any $200 GPS-disciplined oscillator will be orders of magnitude better than that.So, why the fundamental discrepancy? Is it as simple as SNR (V-I-R measurement needs to fight Johnson noise whereas oscillators don't)? Or is there some fundamental Law of the Universe in play.

author: Dr. Frank
author_rank: Super Contributor
timestamp: November 29, 2016, 11:39:43 pm
content: Quote from: wn1fju on November 29, 2016, 10:50:44 pmWell, achieving 1ppmaccuracyfor URI is not so expensive, but 1ppmuncertaintyfor sure is...Just joking..The root cause of the many orders of magnitude of uncertainty lies in the difference between analogue and digital techniques, or the mise en pratique, that is the realization in a working laboratory.Noise is dominant in the analogue world, whereas in the digital world, you are able to mitigate that to many orders of magnitude less.Anyhow, in 2018, when the new SI will be defined, the Volt and the Ohm will be as uncertain and as stable as the other quantum defined units, like the second and the meter.The physics behind this stability is always a quantum phenomenon, but for the analogue units, there will still be no such quantum standard at room temperature, so the home lab will still have to live with stability figures on the order of 10^-7.. 10^-9, compared to 10^-13 for the second.Frank
Low current measurement using a LED and photomultiplier - Page 1
Forum section: electronics / general

author: daqq
author_rank: Super Contributor
timestamp: November 28, 2016, 06:12:17 am
content: Hi guys,After seeing various videos that deal with a photomultiplier and reading a bit on PMTs I've been wondering - would it be possible (or rather would there be a point to) to construct a measurement system that would measure very low currents by means of passing current through an LED, and shining that onto a photomultiplier.This would create an isolated very low current measurement device.Aside from the obvious drawbacks (price, size, temperature dependency, the need to calibrate the heck out of it) it should be doable. What could be the resolution of such a device?Thanks,David

author: MK14
author_rank: Super Contributor
timestamp: November 28, 2016, 06:34:42 am
content: A number of issues, come to mind.There would be quite a lot of voltage drop across the LED, probably around 1.5 to 2 volts, depending on LED colour. I.e. Lots of burden voltage.There is usually a minimum current, below which an LED emits no light. This is probably many, many microamps or more.If you need isolation, then why not measure the current (sensor, sense-resistor etc), then pass that signal through some kind of opto-isolator.The signal could be transmitted digitally (very accurate, ADC or similar), using a linear opto-isolator (potentially much less accurate) or by turning the signal into something else, more easily measured on the other side, such as PWM duty cycle or VCO (voltage controlled oscillator).There are many other ways of doing it (isolated), including transformers (especially AC current) and hall effect sensors.

author: MosherIV
author_rank: Super Contributor
timestamp: November 28, 2016, 07:53:20 am
content: HiThe only application I think this 'may' be of any use is to detect where the line is on an optical galvanometer, the type where the twist on a wire deflects a mirror.

author: Kleinstein
author_rank: Super Contributor
timestamp: November 28, 2016, 05:15:46 pm
content: Good quality LEDs can work well below the µA range. But there will be some nonlinearity and possibly temperature dependence. So I don't think it is very practical. It might be Ok for more like supervision purpose and than using a more normal photo-diode instead of the expensive PMT.There is a more complementary version: use the current of a photodiode (driven by a LED) to compensate the current to be measured. It's a kind of transimpedance amplifier but without the high value resistor and the photo-diode acts as protection device too.I know of an instrument using this to measure currents in the fA-nA range (ion current in a mass spectrometer).
Tinsley 6050 Nanovoltmeter (little bit unsual) - Page 1
Forum section: electronics / general

author: lowimpedance
author_rank: Super Contributor
timestamp: November 18, 2016, 01:08:18 am
content: This somewhat unusual instrument has been sitting on the shelf neglected at work for ............. well who knows.So I thought it would be interesting to have a closer look and post some pics for your entertainment.The first thing that struck me when the cover came off was the similarity to EM nano voltmeters in construction and layout. (some influence perhaps)How ever there is one rather unique difference between the two !. Have a look at the input terminal arrangement..........Its on a slide so it can be moved forward out of the front panel to access screws to attach directly to the copper bars when the banana posts are not good enough. Also the fine twisted enamelled copper wire to the input amp (in mu metal box) has enough strain relief length before being taped to the shielded box to prevent fracture from repeated 'sliding' of the input assemble.A pity the sensitive stuff is glued into the mu metal boxes so it will remain.Overall construction is okay but I prefer the EM gear. And considering the complete lack of any information out there I suspect there wasn't many sold and unfortunately I cannot find the manual that must have come with it. Shame..Has anyone else seen one ?.

author: Vgkid
author_rank: Super Contributor
timestamp: November 18, 2016, 03:09:35 am
content: Thanks for the teardown, shame you can't go deeper.

author: TiN
author_rank: Super Contributor
timestamp: November 18, 2016, 04:28:01 am
content: Is the thin wire from terminal block are thin to keep minimum thermal mass?They just hanging there without any air protection..

author: lowimpedance
author_rank: Super Contributor
timestamp: November 18, 2016, 05:51:04 am
content: That would be my assumption too. Then after the 'loop' section from the sliding terminal they tape it to the shielded box for some length before going into the front end.EM meters use slightly larger gauge copper wire that is sleeved with silicone tube before they loosely twist them together and there is no attaching it to any metal surface between input terminals and the front end (as in the EM 11a thread).

author: Assafl
author_rank: Frequent Contributor
timestamp: November 18, 2016, 02:18:44 pm
content: What do the Yellow and Black wires that go to the same nanovolt bus bars (as the fine wires) do? (they seem to have a resistor or something under black sleeving).

author: guenthert
author_rank: Frequent Contributor
timestamp: November 18, 2016, 04:35:46 pm
content: Neither shield nor guard on the inputs implies it is meant for low impedance sources, right?

author: guido
author_rank: Regular Contributor
timestamp: November 19, 2016, 01:01:59 am
content: Did you ask them for info? In 2012 i requested info on an old AIM/Prism/Tinsley 6451 RLC meter and they mailed me the manual.www.tinsley.co.uk
Keithley 610C Electrometer Calibration and Experiments  - Page 1
Forum section: electronics / general

author: baltersice
author_rank: Regular Contributor
timestamp: December 05, 2016, 02:47:42 pm
content: Not sure if there is any love for old analog stuff in this particular forumBut for the calibration of this electrometer I also used a couple of other precise instruments:

author: VintageNut
author_rank: Frequent Contributor
timestamp: December 05, 2016, 04:00:00 pm
content: Very well done. Thank you for sharing this. The analog meter gives a better "feel" for some measurements which you demonstrated.The 147 and 148 nanovoltmeters are a favorite of mine. They do for low voltage what your 610C does for low current.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: December 05, 2016, 06:04:46 pm
content: Lots of love here- I've got a 610 and (I think) a 602.

author: quarks
author_rank: Frequent Contributor
timestamp: December 05, 2016, 06:47:32 pm
content: Very nice, thanks for showing

author: HighVoltage
author_rank: Super Contributor
timestamp: December 05, 2016, 08:22:06 pm
content: You are showing a very nice capability of your analog electrometer.My 614 Keithley digital electrometer is also great but seeing the needle move with your hand is just something else.

author: enut11
author_rank: Super Contributor
timestamp: December 05, 2016, 08:40:55 pm
content: I love these old analogue meter instruments. There is a certain satifaction in reading off a scale without the distraction of flickering digits. Thanks for sharing. I am inspired to look for another old meter to restore.enut11

author: lowimpedance
author_rank: Super Contributor
timestamp: December 06, 2016, 12:48:51 am
content: Nice old bit of kit in excellent shape to.. Also the moving coil meter is definitely still very useful for certain types of measurement.So still lots of love for the older stuff here.BTW I have a box full of those old connectors you replaced, but yeah not much use these days.
3458A ACAL 0 - Page 1
Forum section: electronics / general

author: klaus11
author_rank: Unknown
timestamp: November 12, 2016, 12:36:15 pm
content: A little help, when executing ACAL 0 does not execute, executes ACAL (simple). I have checked it manually and through GPIB.

author: TiN
author_rank: Super Contributor
timestamp: November 12, 2016, 12:54:08 pm
content: In posts like this one error code or exact description of unit behaviour is a must.My Palantir says you have calibration security activated on the box. Read the manual for commands SECURE and CALEdit: What you trying to do however? There is no specific ACAL 0.

author: klaus11
author_rank: Unknown
timestamp: November 12, 2016, 01:48:06 pm
content: I have tested:3458A: OPT 1; OPT 2FW: 9.1 fresh update ; Docs / xDevsNVRam ALL: Fresh but keep data (may be the problem)Test> PassError Display: NoneAcal: Pass without errors and without asking for security codeACAL 0: Does not execute correctly, Manual Calibration picks up CAL 0 to correct offset.Initial precision: It takes away my dream.I am going to test security code and delete memories physically (it is meant not delete Cal data)

author: klaus11
author_rank: Unknown
timestamp: November 12, 2016, 03:14:25 pm
content: Security code is not the problem, I have touched a bit and blocked and will not let ACAL 0. I will clean NVRam, even though my eyes are heading to the FW.

author: TiN
author_rank: Super Contributor
timestamp: November 12, 2016, 03:16:09 pm
content: I still don't get it.ACAL 0 is same as ACAL ALL, meaning to run autocal for all functions. It's fully equivalent to running just ACAL without any parameters.Try to rephrase it, What are you trying to get as result? Zero calibration is executed by CAL 0 and 4W low-thermal short at the inputs , not ACAL 0. CAL 0 required to execute separately at front and rear terminals.This function did not change external behavior in firmwares since Rev5. I tested myself on Rev5, Rev7, Rev8 and Rev9.

author: klaus11
author_rank: Unknown
timestamp: November 12, 2016, 03:25:00 pm
content: Yes, I am a stupid CAL 0, a video from YouTube confused meThank you TiN. Again a great help.
Looking for information about this OCXO - Page 1
Forum section: electronics / general

author: matthieu.e
author_rank: Regular Contributor
timestamp: November 11, 2016, 09:53:18 pm
content: Hi,I am planning to make a 10 MHz reference with an OCXO I have. It is a Temex DMC2859 but I can't find any informations on it.Have you got a clue ? Thanks !

author: neil t
author_rank: Regular Contributor
timestamp: November 17, 2016, 08:57:09 am
content: try this email address I foundsales@temex-az.com
Keithley 1488 low thermal shorting plug (a quick teardown) - Page 1
Forum section: electronics / general

author: lowimpedance
author_rank: Super Contributor
timestamp: November 18, 2016, 12:12:57 am
content: Found this little accessory while tidying up and though hmmm lets look inside....And what do we see, well not much as to be expected.The plug part is a ITT Cannon (AN3106 !) connector used on various vintage Keithley instruments such as 147, 148, 181, 150b etc.And of course its a crimped connection.The back shell/housing/cap, call it what you like is a rather substantial thermal mass aluminium 'cup' filled with foam which is now disintegrating with age.And that's it...!I did say a quick tear down.

author: VintageNut
author_rank: Frequent Contributor
timestamp: November 18, 2016, 12:24:26 am
content: I have one of those as well and use it with my 147. They work very well for the intended purpose.I think that the standard version of this plug does not have copper pins.

author: lowimpedance
author_rank: Super Contributor
timestamp: November 18, 2016, 12:30:05 am
content: Ah yes these plugs look like they have gold plated copper pins.

author: macboy
author_rank: Super Contributor
timestamp: November 24, 2016, 02:42:26 pm
content: Quote from: lowimpedance on November 18, 2016, 12:30:05 amPerhaps copper-beryllium? Pure copper is very soft as you know, making it unsuitable for connectors - it would wear out in just a few cycles. Adding as little as a fraction of one percent Be can make it literally as strong as steel, although many times the cost, and potentially toxic as well. I think that Cu-Te alloys are similar (and even more expensive) but might have better thermoelectric properties against pure copper than the Cu-Be alloys. I have looked for but haven't found data to back that up.

author: VintageNut
author_rank: Frequent Contributor
timestamp: November 24, 2016, 04:21:06 pm
content: Quote from: macboy on November 24, 2016, 02:42:26 pmGood points. There appears to be no publicly available description of the chemistry of the copper in this plug.Stress on the copper of this plug is much less than any low thermal banana. The copper is embedded in what looks like a plastic/teflon molded plug. There is a key in the plug that guides it into the socket/jack of the nanavoltmeter. It would be difficult to stress the copper during normal insertion of the plug into the nanovoltmeter. The plug and jack are designed so that the plug can only go straight in and come straight out.
Linear AN86-related DAC-Question - Page 1
Forum section: electronics / general

author: Echo88
author_rank: Frequent Contributor
timestamp: November 08, 2016, 09:03:40 pm
content: I was under the impression that in a DAC, once it was set for a value, the corresponding switch will never change its state on its on. But now that i see strange voltage hops on my selfbuilt AN86-dual-DAC-circuit im doubting that. See the attached pictures, it seems to me that these are jumps corresponding to a change in the LSB of the MSB-DAC.Of course in the end the AN86-circuit is closedloop and the error can be disregarded, but it just interests me. Maybe someone can contribute on this topic.My circuit consists of a DC1684A-B 16-Bit-Dual-DAC-board, summed by 0,1% metal-film smd-resistors and a good OP i had laying around (OPA2277 i think). Circuit and DAC-Board of course thermally stabilized for hours and data-control connector disconnected after the 5,0V value was set.

author: Andreas
author_rank: Super Contributor
timestamp: November 08, 2016, 10:15:43 pm
content: Hello,at least the upper trace looks like popcorn noise (of the voltage reference).Which voltage reference does the board use?With best regardsAndreas

author: Cerebus
author_rank: Super Contributor
timestamp: November 08, 2016, 10:18:51 pm
content: Quote from: Andreas on November 08, 2016, 10:15:43 pmThat top trace is nearly 15 hours, those dips are several minutes long.

author: Echo88
author_rank: Frequent Contributor
timestamp: November 08, 2016, 10:23:41 pm
content: It uses the standard populated LTC6655CHMS8-5.

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: November 08, 2016, 10:27:39 pm
content: What are you using for the +/- 15V supply?Also, do you have a way of logging temperature? It looks like the meter is tracking ambient temperature.

author: Andreas
author_rank: Super Contributor
timestamp: November 08, 2016, 10:29:10 pm
content: Hello,not uncommon for certain references.I have this at least on one sample of MAX6350.(plot has 6 minutes total time).With best regardsAndreas

author: Andreas
author_rank: Super Contributor
timestamp: November 08, 2016, 10:32:37 pm
content: Quote from: Echo88 on November 08, 2016, 10:23:41 pmThermally isolated?The 6655 heats quite a lot.Quote from: ManateeMafia on November 08, 2016, 10:27:39 pmI hope the 6655 has a lower power supply voltage than 15 V.With best regardsAndreas

author: Echo88
author_rank: Frequent Contributor
timestamp: November 08, 2016, 10:55:36 pm
content: The LTC6655 isnt thermally isolated and is supplied with 12V. The +-15V are provided by my Agilent 6629A Supply. But if it would be popcorn noise, then the second attached trace wouldnt make sense, as it stays low for about 45mins.http://cds.linear.com/docs/en/demo-board-manual/DC1684AABFB.PDF

author: Andreas
author_rank: Super Contributor
timestamp: November 09, 2016, 07:12:59 am
content: could also be mechanical stress from PCB.I have measured 60-70uV change by applying mechanical stress to a PCB withLTC6655BHMS8-5 mounted in a U-slotted area.with best regardsAndreas
2DW23x order from factory - Page 1
Forum section: electronics / general

author: technix
author_rank: Super Contributor
timestamp: November 07, 2016, 05:28:41 am
content: I have contacted Shanghai No. 17 Radio Factory and they still produces 2DW23x series. If I buy those for you here is the prices:* Price: 75 US cents each, regardless of order size* 50 diodes each pack* Delivery from factory to my home: 2 dollars total if total order is less than 50, free if more.* Delivery from my home to your lab: 5 US dollars for less than 2kgIf you are interested in buying them fresh from the factory, PM me your address and order. I will accumulate it and order it from them directly.

author: technix
author_rank: Super Contributor
timestamp: November 08, 2016, 08:04:08 am
content: The first order have been placed and it will arrive the day after tomorrow. I will have a test rig up to measure the approximate zero TC current (up to 8 bits resolution, 25mA full scale) and send the ones that have ordered pre-matched parts.

author: Gyro
author_rank: Super Contributor
timestamp: November 08, 2016, 10:20:02 am
content: @technix,Good progress.Is the factory able to provide you with a datasheet? Maybe they have useful data on long term drift and noise for their parts.

author: technix
author_rank: Super Contributor
timestamp: November 08, 2016, 01:00:03 pm
content: Quote from: Gyro on November 08, 2016, 10:20:02 amI have told them to send me a copy of their datasheet (or catalog with parameters listed) along with the parts. If I did get one I will make a translation of it.

author: technix
author_rank: Super Contributor
timestamp: November 10, 2016, 05:52:44 am
content: The parts should arrive today. I will send it on tomorrow.

author: technix
author_rank: Super Contributor
timestamp: November 13, 2016, 05:45:32 am
content: Boosting this thread to the top.
Noise Article - Page 1
Forum section: electronics / general

author: VintageNut
author_rank: Frequent Contributor
timestamp: November 06, 2016, 03:20:54 pm
content: Excuse me if this has been posted before.A recent finding that noise is a bulk phenomenon unless your device is 1 atom thick.

author: Echo88
author_rank: Frequent Contributor
timestamp: November 06, 2016, 03:56:30 pm
content: "You kids today have it so easy, with your mobile JJAs which are as big as a pack of cigarettes and your 1-Layer-Graphene-OP-AMPS which have no noise. In my time we had to deal with shitty carbon resistors and lithium accupacks which would explode if not handled right!" *angrily stomps his walking cane on the ground*

author: Gyro
author_rank: Super Contributor
timestamp: November 06, 2016, 04:30:44 pm
content: Quote from: VintageNut on November 06, 2016, 03:20:54 pmActually 6 atoms thick. At that thickness surface noise dominates, above than bulk noise dominates (in Graphene anyway).
METRIX MX57EX  - Page 1
Forum section: electronics / general

author: kardacz
author_rank: Contributor
timestamp: November 05, 2016, 04:05:15 pm
content: Good evening everyone! I own a multimeter METRIX MX57EX (photo) whose memory was corrupted by its former owner (EEPROM: 93C46). Someone would have it you kind enough to make me a copy of its contents ?. In advance merçi much to everyone who can help me!

author: Simon
author_rank: Unknown
timestamp: November 05, 2016, 05:48:53 pm
content: Please don't double post and this is the wrong section as well!
I still have a few LM399's hanging around. Ideas needed. - Page 1
Forum section: electronics / general

author: technix
author_rank: Super Contributor
timestamp: November 04, 2016, 06:36:13 pm
content: Last time I bought a few second-hand LM399's for a potential voltage reference or DIY multimeter project. Now that project seemed to be is all but fizzled out after I bought the UT61D, what can I do with them?Additional parts that also get left behind in that project: MCP3911 dual percision ADC, LT1967 RMS to DC converter, ADR02B and ADR03B reference, and some precision resistors. Those are all brand new and are now sitting in baggies collecting dust.Should I keep pushing that project on? If so, how do I deal with the highly sensitive inputs of MCP3911 with only a dual-layer board? Also how should I design an analog front-end around it? I also want to make use of the dual converter inside MCP3911 if possible.If I should not push on, then how can I deal with those components, which aren't exactly cheap.
Request for Power Level Meter Operations and Service Manual - Page 1
Forum section: electronics / general

author: mdbarg
author_rank: Newbie
timestamp: October 31, 2016, 09:14:46 pm
content: Does anyone have a scanned or digital copy of the subject manual for an Arbiter Model 1096A Power Level Meter they could send to me? I have this test equipment, used with a Keithley Model 199 DMM/scanner, to measure RF power output in conjunction with a thermister mount. I know there are other, possibly simpler, commercial solutions available, but this one is a challenge. Thank you for your patience and kindness!
arithmetic mean value vs TRMS AC+DC - Page 1
Forum section: electronics / general

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: November 07, 2016, 09:41:31 pm
content: Maybe this question will be dumb ,but im just an hobbyst in electronic fieldSo i want to ask you today if it's still good to buy an multimeter without TRMS ,only arithmetic mean valueThere is a good guy ,which want to sell me an gossen metrawatt 23s and i don't know if this deal worth or not.

author: helius
author_rank: Super Contributor
timestamp: November 07, 2016, 10:52:12 pm
content: It only depends if you care about the accuracy of AC measurements on non-sinusoidal signals (such as square waves or PWM signals). Some high-priced meters do not have TRMS, such as Metrahit 27: some users simply do not need it. But if you will test things like triac light dimmers, TRMS is useful to have.

author: 2N3055
author_rank: Super Contributor
timestamp: November 07, 2016, 11:41:39 pm
content: Also any work on audio needs TRMS... and about 100 kHz of bandwidth...

author: David Hess
author_rank: Super Contributor
timestamp: November 08, 2016, 12:02:58 am
content: Unless you already have an application which needs RMS measurements, I would not worry about it.I actually prefer to disable RMS on my RMS meters if possible because it slows down the settling time a lot with lower signal levels; in some cases it can take 10s of seconds to settle. I only use it when absolutely necessary which is rare.

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: November 08, 2016, 12:11:22 am
content: Actually im working on this projecthttps://www.eevblog.com/forum/projects/diy-metcal-13-56-mhz-rf-supply/

author: 2N3055
author_rank: Super Contributor
timestamp: November 08, 2016, 07:13:04 am
content: Normal multimeters will not work on 13 MHz in AC mode... Most are few kHz and good ones are few 100 kHz.. For 13 MHz you'll need an oscilloscope or RF multimeter..In practice that means you need oscilloscope...
M48Z58-70PC1 - Page 1
Forum section: electronics / general

author: kardacz
author_rank: Contributor
timestamp: October 26, 2016, 12:37:52 pm
content: Hello everyone! I have to reprogram EEPROM: M48Z58-70PC1 (new) with a programmer: TL866CS, and I can not find it in the list; even manually, it appears to me to me: "unknown." How to do??? Someone an idea? (I own the original memory). Thank you for your help!

author: quarks
author_rank: Frequent Contributor
timestamp: October 26, 2016, 02:26:27 pm
content: I do not have your programmer, but you can check if you find Dallas DS1230AB (which I guess is compabible, but please check yourself first) and try itBTW: The Metrology subforum is probaly not the best choise to ask this

author: TiN
author_rank: Super Contributor
timestamp: October 26, 2016, 02:41:29 pm
content: It's not metrology-grade thread, but I agree with quarks. Try DS1230 or regular SRAM, as last time I remember it was standard JEDEC-pinout. Didn't check before post.

author: kardacz
author_rank: Contributor
timestamp: October 29, 2016, 08:47:22 am
content: Hello; actually I tried: and miracle, it works! Thank you very much; I will return to this forum !!
[QUESTION] Saving the display during remote data acquisition - Page 1
Forum section: electronics / general

author: doktor pyta
author_rank: Frequent Contributor
timestamp: October 24, 2016, 09:36:31 am
content: Many of us use nice and expensive multimeters for data logging during long period of time.Do You have any hints (commands/ tricks) to make the display blank during acquisition ?This particularly is related to:Keithley 2000, 2015, 2010, 2001, 2002 and similarDatron 1071, 1081 and similar (with neon display)Datron 1271, 1281 and similarHP 34401A, 3458A and similarAdvantest R6581TAs an owner of Datron 1271 I must admit that I haven't found any suitable GPIB command in the user's manual so I added little switch that turns off power for heaters of two VFD displays.For some of these DMMs it may be a good idea to take over control over the display using GPIB command and send text filling the display with multiple 'space' character.Your comments and suggestions are welcome.

author: klaus11
author_rank: Unknown
timestamp: October 24, 2016, 01:32:26 pm
content: TiN mentions in his review-repair of the 3458A command: DISP OFF,' 'https://xdevs.com/fix/hp3458a/

author: saturnin
author_rank: Regular Contributor
timestamp: October 24, 2016, 02:32:17 pm
content: :disp:enab offcommand works for Keithley 2000, 2015, 2010 (supported both by RS-232 and GPIB) ...

author: TiN
author_rank: Super Contributor
timestamp: October 24, 2016, 04:08:02 pm
content: K200X\K24XX (I believe also 26XX, but did not check, as I have none of those beasts):kei.write(":DISP:WIND:TEXT:DATA \" \";STAT ON;")kei.write(":DISP:WIND2:TEXT:DATA \" \";STAT ON;")
Electrostatic Voltmeter Verification - Page 1
Forum section: electronics / general

author: ultrasmurf
author_rank: Regular Contributor
timestamp: October 17, 2016, 12:32:15 pm
content: Guys, I just got myself some electro static measurement probe and PCB attached to it. Suppose to be working, and I can probably check the output easily. Question is, how do I know it is measuring somewhat in the ballpark region ? Doesn't need to be 1% accurate but not in the 50% region as well.. I'm thinking of rubbing my hair... but what will be the reading for that ? 7kV ? or will it be a large possible range that is quite useless to see whether the device can indeed work and measure somewhat reliably ?

author: doktor pyta
author_rank: Frequent Contributor
timestamp: October 17, 2016, 08:19:41 pm
content: AFAIK it is the compensating electrostatic voltmeter (it has built in positive and negative high voltage DC/DC converters). That is why the calibration should be easy, because the distance from object to probe is not affecting the measurement (as long as it does not disturb the electrostatic field).TREK documenthttp://www.trekj.com/products/pdf/3001_Vibrating_Probe.pdfSo take a metal plate MUCH larger than the probe dimension and connect it to a known DC high voltage. You may also use a metal can with no sharp edges instead of the plate. Place the probe say 2cm from the probe or inside the can. Both: TREK board and the voltage source must be grounded to the same point. The probe may be at high potential so be careful.EDIT: this patent describes the conception and the error vs. distance issue:http://www.google.com/patents/US20080079435

author: ultrasmurf
author_rank: Regular Contributor
timestamp: October 19, 2016, 05:10:25 pm
content: Thanks for the link. Was reading it and bunch of other article about kelvin probe. Anyho, board was broken, the optocoupler was shot. Ordering replacement part for it...I have a hene laser setup, so pointing the probe somewhat close to the anode side of the laser tube should give me a reading right ? And I know the tube should be lit at about 1KV.
Thinking of getting my 17025 - Page 1
Forum section: electronics / general

author: challie2
author_rank: Contributor
timestamp: October 13, 2016, 11:25:48 am
content: Hi,I am thinking about getting a 17015, and starting a small LTD Company.Can someone tell me what equipment, and insurance i would need.also can I calibrate my own tools? under UKAS if i get the 17025?Thanks