hybridfree/eevblog-posts huggingface dataset:
LTspice models - pcb traces and wires - resistance and tempco - Page 1
Forum section: electronics / general

author: iMo
author_rank: Super Contributor
timestamp: February 07, 2023, 11:45:28 am
content: I've been putting this into Metrology as I think people here could be interested..Enclosed the models of "pcb Trace" and "Rwire" for playing with your designs, especially while chasing microvolts.Inspired by an older Bordodynov library I made changes and put it here as .lib and .asy files. You may put it inside your LTspice and use easilyNote the stuff could be improved - for example the fonts and the position of the attributes (and perhaps the models too), but I do not know how, you may tell me then.Below a sim with the new symbols/models..Mind the lengths, diameters, widths are in "meters" (like "100m" means 100mm==10cm), tempcos are related to 27C in the LTspice.The copper pcb trace thickness is set to 35um.
Fluke 5500A Output Block Replacement - Page 1
Forum section: electronics / general

author: salayhan
author_rank: Newbie
timestamp: January 20, 2023, 12:18:11 pm
content: We would like to replace the Fluke 5500A calibrator output block, but are not available from Fluke.How can I get this part?

author: alm
author_rank: Super Contributor
timestamp: January 20, 2023, 12:48:58 pm
content: Those connectors don't look so bad to me. Looks like only part of the insulation is broken?I occasionally see Fluke calibrator connector blocks offered for sale on eBay, likethis. But unfortunately I don't see any for the Fluke 5500A right now. Maybe if you're patient one will show up eventually?

author: laichh
author_rank: Regular Contributor
timestamp: January 20, 2023, 12:59:26 pm
content: I would replace them with a low thermal binding post such as:http://www.lowthermal.com/cables-and-connectors.phpBinding post is much more useful than shrouded banana jack.

author: Overspeed
author_rank: Frequent Contributor
timestamp: January 20, 2023, 01:19:06 pm
content: HelloI think Marcus Rep on Youtube have make a cloneRegardsOS

author: manganin
author_rank: Regular Contributor
timestamp: January 20, 2023, 01:33:14 pm
content: Quote from: salayhan on January 20, 2023, 12:18:11 pmFirst check if the 5500A shares the worn out safety banana plastic parts with some Fluke multimeter of the same era.Quote from: laichh on January 20, 2023, 12:59:26 pmIn a home lab yes, but in commercial use it will be a safety issue. Not in real life, but from the regulations point of view.

author: alm
author_rank: Super Contributor
timestamp: January 20, 2023, 01:51:59 pm
content: Quote from: manganin on January 20, 2023, 01:33:14 pmDidn't contemporary 5700 series calibrators ship with regular binding posts, and have the same output voltage range?If the TS does decide for conversion to binding posts, then forum user branadic is offeringlow thermal binding postsuntil the end of January.
Who has the circuit diagram of Keithley 6221? - Page 1
Forum section: electronics / general

author: John ST
author_rank: Newbie
timestamp: January 16, 2023, 03:52:15 am
content: Who has the circuit diagram of Keithley 6221?Do you have interest in designing one ?

author: sahko123
author_rank: Frequent Contributor
timestamp: January 16, 2023, 09:54:45 am
content: are you looking to repair it or copy the design?

author: John ST
author_rank: Newbie
timestamp: January 17, 2023, 03:19:29 am
content: I want to design it or make a same one.
PRS-10s galore - Page 1
Forum section: electronics / general

author: tomnut
author_rank: Newbie
timestamp: January 20, 2023, 09:32:41 pm
content: For the collectors - Solano has just listed about 14 PRS-10 Rubidium clocks on ebay, from the "TC" collection.Untested. They look clean. All come with either a simple cable or a full break-out board.Might have been manufactured around 2000.The price might be quite negotiable.
Hantek 365 comms protocol ?  - Page 1
Forum section: electronics / general

author: MadScientist
author_rank: Frequent Contributor
timestamp: December 21, 2022, 02:33:25 pm
content: Anyone got the comms protocol documented for the this data logger ?Thanks

author: bidrohini
author_rank: Regular Contributor
timestamp: January 11, 2023, 02:17:09 am
content: This is an open-source GUI for the Hantek 365 Datalogger in Linux and Windows. Includes a command line utility.https://github.com/mp035/hantek-365
Warburton franki - Page 1
Forum section: electronics / general

author: merser
author_rank: Contributor
timestamp: January 04, 2023, 09:02:22 pm
content: I have an old warburton franki 20Mhz oscilloscope bought in early 90's when I did post trade electronics classes. I can't seem to find any information about it on internet. It seems like it could use a bit of a service. Model wo-20

author: Whales
author_rank: Super Contributor
timestamp: January 04, 2023, 09:35:18 pm
content: It may have been a whitelabelled unit.I can't find any photos on the web, could you please post a photo?

author: Greybeard
author_rank: Frequent Contributor
timestamp: January 06, 2023, 09:13:25 am
content: This one?https://worldradiohistory.com/hd2/IDX-UK/Technology/Technology-Modern/Archive-Electronics-Today-IDX/IDX/AUSTRALIA/ETI-1975-02-OCR-Page-0087.pdf

author: merser
author_rank: Contributor
timestamp: January 08, 2023, 11:30:08 am
content: Hi, it was in storage most of these past years and for some reason I thought it was a techtronix. I have a feeling it was bought from a techtronix supplier.https://www.flickr.com/photos/87212000@N05/52614771045/in/album-72177720305083009https://www.flickr.com/photos/87212000@N05/52614340791/in/album-72177720305083009/Tried image attachment but couldn't get it to work.The only thing I was aware warburton franki was making were the old power meters.regardsmike

author: doktor pyta
author_rank: Frequent Contributor
timestamp: January 08, 2023, 01:23:22 pm
content: This oscilloscope is noting but re-branded Hung Chang device sold under many brands - examples in the attachment.You can google for these alternate types to find a manual.

author: merser
author_rank: Contributor
timestamp: January 09, 2023, 04:51:18 am
content: Thankyou Doctor Pyta, I obviously recalled wrong I think I know where it was bought now. At least now I can find a manual. Much appreciated.
TESTER TC-1 - Page 1
Forum section: electronics / general

author: lionelkjh
author_rank: Frequent Contributor
timestamp: January 04, 2023, 04:41:59 pm
content: Goodnight all! I am looking for the USB cord to charge the Chinese TC-1 tester; could someone help me find it?? Thanks for your help!

author: 807
author_rank: Frequent Contributor
timestamp: January 04, 2023, 04:53:05 pm
content: Have you tried looking down the side of the sofa?Mine came with a 20cm USB A to micro USB lead. It's the same connector as used on my Android mobile phone.

author: Gyro
author_rank: Super Contributor
timestamp: January 04, 2023, 05:35:55 pm
content: Quote from: lionelkjh on January 04, 2023, 04:41:59 pmDuplicate thread, the previous one was moved to the appropriate location (Test Equipment).

author: Simon
author_rank: Unknown
timestamp: January 05, 2023, 08:45:45 am
content: Please do not double post, it will make you no friends....
Possible Sunset Info for the Saga of Neons for the HP 419A Meter - Page 1
Forum section: electronics / general

author: gridleak
author_rank: Contributor
timestamp: January 04, 2023, 02:46:19 am
content: I want to leave thses final thoughts on neon lamps for the HP 419A. The only current discussion about those neons ( on groups.io HP forum) revolves around replacing the neons with optocouplers and LEDs. That's the best move. For those of us who are fossils, and won't give up on neons, let me share these observations. If an HP 419A drops in your lap, with dead neons you will NEVER get things working with any arbitrary ne2 style lamp. First, you must use dark effect treated lamps. The NE2H is listed as dark effect treated. Another lamp I have used is the A3C which is dark effect treated and qualified for chopper applications. However, I never got either of these lamps to fire properly in the HP 419A unless I added this circuit :https://dabbledoo.weebly.com/hp419a.html. The only lamp that worked out of the box was one suggested by a volt/nut subscriber: GT-NE6H1925T. I have used these in my 419 twice with success. I think they work because of "poor quality control" causing enough difference in specs between individual lamps to satisfy the the trigger requirements for oscillation. The GT-NE6H1925T is now unobtainium leaving the additional circuit route as the only way out.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: January 04, 2023, 12:53:18 pm
content: Thanks for that! I have two of them that I need to get after at some point. Always liked the way they worked, sometimes better than my Fluke 845.
Dual Source Bridge - Page 1
Forum section: electronics / general

author: VintageNut
author_rank: Frequent Contributor
timestamp: December 21, 2022, 08:05:18 pm
content: TiN discussed with me a dual source bridge concept. I have started with 1/2 of this bridge shown here. The voltage source is an ADI AD5791+LTZ1000 with a DMM7510 monitoring the output. I have a nominal 1G resistor in a Keithley triax fixture. Current is measured on the low side with a 6430.The second half of the bridge will be a Fluke 731B which is stable and quiet enough.The final piece will be a calibrated 1G resistor which is yet to be acquired. I have a Fluke 5450A which has a calibrated 100M ohm.Another plan is to make a Hamon divider with 10 pcs of 1G resistor so that I can span from 100M to 10G
3 Wire Earth Resistance Tester - Page 1
Forum section: electronics / general

author: crysti
author_rank: Regular Contributor
timestamp: December 09, 2022, 07:44:08 pm
content: Does anyone have a internal diagram scheme for 25 Ohm Calibration Checker for Ground Testers calibrating with 3 wire?Thanks in advance!

author: mendip_discovery
author_rank: Super Contributor
timestamp: December 10, 2022, 08:51:58 am
content: From the ones I have seen it is just some smd resistors. Can't remember the configuration but shouldn't be too hard with a few resistors.

author: crysti
author_rank: Regular Contributor
timestamp: December 10, 2022, 11:14:34 am
content: I not have access to a real calibrator. And I can't buy one because it's too expensive for me. It costs $100 plus shipping and taxes, just for a few resistors.

author: mendip_discovery
author_rank: Super Contributor
timestamp: December 10, 2022, 11:28:55 am
content: They often ship with the tester as they are meant to be a quick check before using the meter.I have seen one or two, and I did take some photos once as I planned to make my own. Though I have just found it easier to just measure the resistance of the quick check part with my DMM then use that. I have used some 1% resistors that I have around to add some extra points to the certificates.

author: crysti
author_rank: Regular Contributor
timestamp: December 10, 2022, 05:19:24 pm
content: Quote from: mendip_discovery on December 10, 2022, 11:28:55 amYou can post a diagram with resistors?Thank you!

author: bck
author_rank: Contributor
timestamp: December 11, 2022, 04:19:10 am
content: since the three connectors on the left side are bridged together and the two on the right side are bridged together, the resistor has to be between those two? see picture

author: mendip_discovery
author_rank: Super Contributor
timestamp: December 11, 2022, 10:19:56 am
content: Here is one for the clamp style units,https://www.calibr8.net/calibration-loop-for-clamp-type-earth-resistance-testers-1476-p.aspThen here is the one for the megger units.https://www.test-meter.co.uk/megger-earth-tester-calibration-checkbox-1000-435It's just a 3 or 4 wire resistance measurment. A 0.1% 25ohm resistor is all that is needed.
Any decent MSF receiver projects out there? - Page 1
Forum section: electronics / general

author: djsb
author_rank: Super Contributor
timestamp: November 29, 2022, 11:40:43 am
content: Are there any MSF (https://en.wikipedia.org/wiki/Time_from_NPL_(MSF)) receiver projects that anyone knows about? Is there anything that can make use of any digital information that is transmitted? Are the MSF receiver modules from China any good? I know that these MSF receivers are now probably redundant due to GPS, but maybe they are useful as a backup reference. Any thoughts?David.PS Has anyone in the UK made use of the WWV transmissions from NIST in the USA?

author: jpanhalt
author_rank: Super Contributor
timestamp: November 29, 2022, 12:10:08 pm
content: Do you want a clock or a receiver to monitor?In the former instance, look for "atomic clocks." They are cheap and are a typical clock that periodically (e.g., once a night) captures the time signal and self-correct.If you want to build a receiver, consider 4 options:1) Harvest one from an atomic clock2) Buy a kit. They used to be common (e.g., CMMR-6), but that source has dried up. Here's another source:http://www.auroralchorus.com/wr3gx2.htm3) Buy an SDR dongle/receiver4) Roll your own. See SID imageI did all four and the journey was fun, particularly writing the code to decode the signal, which in the US is WWVB. Attached are pictures of my antenna, receiver decoder, and a simple schematic.Once the fun was over, I just bought a very inexpensive "atomic" clock and keep it next to my workbench.

author: mendip_discovery
author_rank: Super Contributor
timestamp: December 01, 2022, 08:24:00 pm
content: I already have a NTP service from my Lightning Detector but I plan to go GPSDO soon but would be fun to play with MSF as well. Compare the 3.Though I have lots of ideas not enough to action them all.

author: tomnut
author_rank: Newbie
timestamp: December 07, 2022, 08:46:02 pm
content: This project uses a Raspberry Pi Pico as a direct sampling receiver, DSP and time decoder. This kind of minimalism pleases me greatlyhttps://www.elektormagazine.com/articles/raspberry-pi-pico-makes-an-msfsdrSource code might be here:https://www.elektormagazine.com/magazine/elektor-260/60555
Blackstack replacement - request advice - Page 1
Forum section: electronics / general

author: nugab2
author_rank: Newbie
timestamp: November 28, 2022, 05:28:18 pm
content: I have been tasked with replacing my company's two Fluke 1560 Blackstacks that we use for RTD calibration. They are old and have more and more problems every year. We have several hundred Class A, 4-wire, PT385 RTDs.After looking around I can't really find anything comparable to the 1560s. Fluke's recommended replacement, the 1586A doesn't seem like much of an upgrade.Can anyone here recommend instrumentation they've worked with that would be a competent replacement?we use Met/Temp II for data logging.Thanks.

author: RYcal
author_rank: Contributor
timestamp: November 28, 2022, 09:33:41 pm
content: I have used the 1586A's in the past they are good units when setup correctly.

author: mzzj
author_rank: Super Contributor
timestamp: November 30, 2022, 09:27:22 pm
content: Quote from: nugab2 on November 28, 2022, 05:28:18 pmWhat kind of upgrade you are looking for? Accuracy, speed, channel count?Fluke 1594A + 2590 Multiplexer gives you 13 channels and way better accuracy than 1586A but the price is also from different planet.On the other hand if you need lots of channels but can cope with lower accuracy something like Keithley DAQ6510 could be suitable

author: CorporateReference
author_rank: Contributor
timestamp: December 02, 2022, 12:07:24 am
content: It is hard to recommend without fully knowing what type of RTDs you want to calibrate, your accuracy requirements, connections, etc. Do you want them to calculate ITS-90/CVD coefficients in instrument? The black stack was great because the binding posts are right there on top and easy to connect to anything.If you want to stick to Fluke, email temperaturesupport@flukecal.com and tell them exactly what you need. Shane or Emmanuel are very experienced engineers who can recommend you a product or answer questions.Otherwise, you could also look at a readout + iPad/PC software to calculate the coefficients.
Indoor Air Quality - Detect Fuel (gasoline)? - Page 1
Forum section: electronics / general

author: AJhowl
author_rank: Newbie
timestamp: November 16, 2022, 02:05:52 pm
content: Hello,I have a small mechanics repair shop.Sometimes I open up fuel tanks and there's strong gasoline smell.Is there a "gasoline" (or fuel) detection sensor?Either something pre-packaged from a company, or something hackable?Something hackable could be with a raspberry pi, or ESP board, or something of the like.Any thoughts?Thank you! I don't want to have too high of a smell in there and not realize it.

author: mendip_discovery
author_rank: Super Contributor
timestamp: November 16, 2022, 07:35:31 pm
content: https://www.force4.co.uk/item/BEP/LPG-and-Petrol-Fume-Sensor/DJCThey do lots of these for boats so they should be fairly easy to find.

author: james_s
author_rank: Super Contributor
timestamp: November 16, 2022, 07:40:20 pm
content: What you're looking for is a TVOC sensor, there are quite a few to choose from. Some are more specific to certain compounds than others.

author: TUMEMBER
author_rank: Regular Contributor
timestamp: November 17, 2022, 08:38:51 am
content: Quote from: AJhowl on November 16, 2022, 02:05:52 pmIf you have programming skills in C++, the arduino plus MQ135 gives you the ability to measure gasoline vapor concentration levels. You can't measure the exact values, but the levels are.https://www.waveshare.com/w/upload/7/71/MQ-135.pdfhttps://pl.aliexpress.com/item/32900613318.html?spm=a2g0o.order_list.0.0.21ef1c24s6mHmn&gatewayAdapt=glo2pol

author: AJhowl
author_rank: Newbie
timestamp: November 22, 2022, 06:16:53 pm
content: Thank you all for your replies!I'm opening links now and studying what to do.Awesome! I'll update this thread with whatever I end up doing.Have a good one!
The beginnings of my little metrology lab - Page 1
Forum section: electronics / general

author: RoadDog
author_rank: Regular Contributor
timestamp: November 14, 2022, 09:40:54 pm
content: Quite the week on eBay. 845 seems ok not sure yet with a Fluke 45 and cheap power supplies. The set screw on the range switch came loose so I’m hoping that’s all that was wrong with it when they pulled it.335a should be here tomorrow. It appears to be putting out correct voltages against a 6 1/2 digit meterMy first pieces of metrology grade gear. I probably won’t go to 8 1/2 digits like some of you but I’ll see how far I can get on the cheap.Have some lm399s and other parts on the way to build references.Cal stickers are still intact on the 335a so it probably hasn’t been butchered. Will be interesting to crack it open and take a peek inside to see if the caps and anything else has been replaced. Been told it’s $100+ project and a lot of work to recap them.I’m excited to say the least.

author: enut11
author_rank: Super Contributor
timestamp: November 14, 2022, 10:05:03 pm
content: @RoadDog, exciting times indeed. The hardest part is waiting for the goods to arrive.If you need any docs, just shout. Someone on the Forum will have a copy.I have owned all of the above, all fine gear. You just need lots of bench space!enut11

author: sokoloff
author_rank: Super Contributor
timestamp: November 14, 2022, 10:10:48 pm
content: Is the 335 coming from Antarctica or something? (That's a stiff shipping charge.)Congrats on the gear; hope it all arrives in good order and the case of TEA that you get is milder than your wallet can support.

author: RoadDog
author_rank: Regular Contributor
timestamp: November 14, 2022, 10:22:49 pm
content: Quote from: sokoloff on November 14, 2022, 10:10:48 pmThanks! Yeah the shipping seemed a bit excessive but the fact that it hadn’t been cracked open and seemed to be in working order along with very positive feedback on his seller profile sold me. It was on the other side of the country and I figure he packed it very well so hoping it’s a good buy.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: November 16, 2022, 12:27:50 am
content: If you stick to 6.5 digits you can go far on a budget. Beyond that, costs increase rapidly!

author: PixieDust
author_rank: Frequent Contributor
timestamp: November 17, 2022, 07:40:19 am
content: Quote from: Conrad Hoffman on November 16, 2022, 12:27:50 amThis is music to my ears, my multimeter is 5.5 digits. So sounds like I should be able to calibrate it for a reasonable price!
What Is Stability? - Page 1
Forum section: electronics / general

author: PixieDust
author_rank: Frequent Contributor
timestamp: November 05, 2022, 02:11:40 am
content: Is it just how well a component maintains its spec with time? Pretty sure I'm right but just want to confirm.

author: Kleinstein
author_rank: Super Contributor
timestamp: November 05, 2022, 06:44:00 am
content: It is usually not just the effect of time, but also the effect of temperature, humidity and other envirnmental variations (air pressue, magnetic field, PCB stress).The temperature effect is sometimes handled separately. With humidity it is difficult and thus uncommon to handle this by an extra coefficient, as there is often quite some delay.

author: dietert1
author_rank: Super Contributor
timestamp: November 05, 2022, 07:02:00 am
content: The most difficult aspect is time, as you can't revert it. You can watch a precision setup and later make some theory about what you saw, but it will be always late. A large fraction of it's lifetime may have been wasted until you "understand" what is going on.Regards, Dieter

author: hgl
author_rank: Regular Contributor
timestamp: November 05, 2022, 10:09:13 pm
content: Time is an intrinsic property of stability and thus all physical properties of the object under study and all environmental conditions over time determine stability. A component that does not age and the environmental conditions never change will be stable over time.

author: mendip_discovery
author_rank: Super Contributor
timestamp: November 06, 2022, 09:28:26 pm
content: To keep it in recognised terminology just refer to JCGM 200:2012 from BPIM.Quote

author: dietert1
author_rank: Super Contributor
timestamp: November 07, 2022, 09:18:48 am
content: Yes, one can try to model/predict/specify aging of parts or equipment. Yet we should be aware that engineers use temperature cycles to accelerate aging. TC measurements involve temperature cycles, too. And lots of equipment suffer day/night temperature cycles.When somebody sends a device for calibration, it may suffer large temperature cycles - on the way to the calibration lab and also on the way back - after calibration. This is why specifications of stability (e.g. ppm/year) don't represent actual observations but include large error margins, like 10x or more.Regards, Dieter

author: PixieDust
author_rank: Frequent Contributor
timestamp: November 10, 2022, 03:58:23 am
content: Thanks guys!
Usage of HP E1938A EFC - Page 1
Forum section: electronics / general

author: stevenlvv
author_rank: Newbie
timestamp: November 03, 2022, 12:33:53 pm
content: Hi, how do I use of EFC+ and EFC_SHIELD of HP E1938A OCXO? Are they for frequency adjustment? Thanks!

author: borghese
author_rank: Regular Contributor
timestamp: November 03, 2022, 04:56:09 pm
content: Credit to Rick Karlquist, the designer
Logging Instrument purchase - Page 1
Forum section: electronics / general

author: laban93
author_rank: Contributor
timestamp: November 03, 2022, 08:18:07 am
content: Hi all,In our industrial worksite we do a lot of troubleshooting, and are in need of a portable instrument with logging capabilities and 4+channels. We currently have not one but two yokogawa DL850E scopecorders, but as i am one of the few who knows how to operate this, and the fact that it's in 2 giant peli cases (one for instrument, and one for probes) makes this a real hassle when bringing it inside crane pedestals and so on.Is there a easy to use, portable, logging capable instrument like this available?

author: DavidKo
author_rank: Frequent Contributor
timestamp: November 03, 2022, 08:48:37 am
content: Hard to say if it fits your application. Hioki is producingdata loggers.

author: HighVoltage
author_rank: Super Contributor
timestamp: November 03, 2022, 09:57:14 am
content: What kind of signal do you need to log?Just DC voltage or some complex waveform?

author: 2N3055
author_rank: Super Contributor
timestamp: November 03, 2022, 10:58:03 am
content: Well DL850E is a modular platform with huge capabilities. Something with similar capabilities would probably be same size.But that is a wrong way of going about this problem.You need to define if you really need ALL of capability of DL850E and if not, what would be requirements?Input types, ranges, speed, resolution, number of channels, length of logging and type of platform. Can you log to file and look at it later...So my advice is to first compile a definite requirement list and only then you can start to look for alternatives.There are no good answers to wrong questions...

author: DavidKo
author_rank: Frequent Contributor
timestamp: November 03, 2022, 11:04:44 am
content: Yokogawa have smaller versions in theScopecorderrange.

author: laban93
author_rank: Contributor
timestamp: November 03, 2022, 05:41:20 pm
content: No, all the functions we would need for serious troubleshooting are well covered by our big scopes. Just need something you can bring along with ease, and measure say minimum 4 voltages/mA currents, and logg them over at least 12 hours if there is such a tool.

author: miro123
author_rank: Frequent Contributor
timestamp: November 03, 2022, 07:22:39 pm
content: Quote from: DavidKo on November 03, 2022, 08:48:37 am+1., I also prefer to use Hioki power and datalogers. They are small robust and easy to use. I cannot remember when I used the bulky and cumbersome HP34970a for last time
Fluke 803 green barrel-type resistor specs needed - Page 1
Forum section: electronics / general

author: enut11
author_rank: Super Contributor
timestamp: November 02, 2022, 09:40:27 pm
content: I have several large green precision resistors salvaged from a Fluke 803 voltmeter. The larger ones are approx 1"x0.5"diam and the smaller ones are 0.5"x0.5"diam.112482111906Is there a way to identify the tempco specs from the id number on the resistor?enut11

author: enut11
author_rank: Super Contributor
timestamp: November 02, 2022, 10:33:59 pm
content: All the resistors are associated with the voltage range selector switches S2E and S5G

author: wolfy007
author_rank: Frequent Contributor
timestamp: November 03, 2022, 03:21:27 am
content: I remember reading somewhere they were like 5ppm/degreeC tempco, at least those smaller .05% ones are.

author: enut11
author_rank: Super Contributor
timestamp: November 03, 2022, 05:09:40 am
content: Thanks @wolfy007. That sounds encouraging and may be just what I need to make a good wheatstone bridge
Advantest R6552 dim display - Page 1
Forum section: electronics / general

author: wd5jfr
author_rank: Regular Contributor
timestamp: October 31, 2022, 01:56:08 pm
content: Just got one for $60 with a dim display. The manual says life of display 2.5 yrs. Can't find much info on it, so I guess Advantest is not a very popular instrument, should have done my home work. Any suggestions appreciated. I see in the specs that it can measure 0.1 microvolts DC, anyone done this, and what for?ThanksHank

author: mendip_discovery
author_rank: Super Contributor
timestamp: October 31, 2022, 02:49:53 pm
content: 5.5 digit meter,Specs here.https://www.allaboutcircuits.com/test-measurement/multimeters/advantest-r6552/datasheet/Screen, no idea.

author: n_haku
author_rank: Contributor
timestamp: October 31, 2022, 03:28:10 pm
content: VFD Display was the reason why I choose r6551 instead of r6552, although w/o 30mV range.Another killer feature is normal binding post as rear input instead of banana plug while front are bananas for ordinary test leads (seriously, why modern dmm not like this).As for dim problem, there are some information about successfiull restoration,hereandhere.Also be prepare to replace electrolytic caps, mine had significant noise until I recapped and well cleaned board.

author: wd5jfr
author_rank: Regular Contributor
timestamp: October 31, 2022, 09:57:45 pm
content: I should have sent pics of what it looks like in a dark and lit room. If all the digits where as bright as the last one the display would be acceptable. I wonder if this provides any clues of what might be wrong. I don't have a service manual and know nothing about VFDs and don't have a constant current supply so I not equipped to bugger it up. But I'll check the power supply voltages and see if they are correct and check for ripple Since I didn't have enough knowledge before buying it at a hamfest, it's my bad. I'm also curious why any competent service organization would buy one of these if the VFD life is listed at 2.5 years. That 2.5 year VFD life would lead one to think that there should be some NOS VFD replacements. Thanks for the tips.Hank

author: wd5jfr
author_rank: Regular Contributor
timestamp: October 31, 2022, 11:52:41 pm
content: As I was removing the case I noticed the fuse holder voltage was set for 100 so I reset it for 120. Who knows, it may have been set this way since new. So my guess is it has been operating at 120 volts, but I would think the power supply has a regulator but I couldn't see one. The bridge rectifier has about 8.4vdc and the largest close by electrolytic is 10,000 mfd at 16 volts with 8.3 vdc on it and 84 millivolts ac. I can't say with any certainty with my 82 year old eyes that it's less but it seems to be. Probably wishful thinking, but I think I may be able to use it as is but I'd like to find a replacement.Hank
Need a recomendation on cables - Page 1
Forum section: electronics / general

author: Zenwizard
author_rank: Regular Contributor
timestamp: October 28, 2022, 05:11:00 pm
content: What is a good set of cables to use on a fluke 5200A. I would like to get a set of shielded cables if I can because I have some excess noise in the lab that really gets ugly on the lower ranges. I will also need 2 sets because I would like to use remote scene. I need a bit of length because I dont want to have to move the 5200 or 5205 around the lab if I can help it. There is some gravity in those.Zen

author: alm
author_rank: Super Contributor
timestamp: October 28, 2022, 05:52:32 pm
content: This is only for the 5200A, right, since the 5205A has it's own permanently-attached lead? I'd say two sets shielded twisted 2-wire leads terminated on low-EMF spade lugs on the 5200A side and either low-EMF spade lugs or low-EMF banana plugs on the other side. Pomona or Fluke might sell something like this for $$$, or you can make them yourself.Member ap low-EMF cables and parts, but this may not be so convenient in the US. MaybeLowThermal?

author: Zenwizard
author_rank: Regular Contributor
timestamp: October 28, 2022, 07:01:13 pm
content: It does have a permanently attached lead bit I will need something a bit longer at some point. The 5205 lead comes out as 4mm banana at the end.

author: alm
author_rank: Super Contributor
timestamp: October 28, 2022, 09:44:09 pm
content: Looking at the service manual, the 5205A extends remote sensing until the end of the cable, so ideally when extending you would also extend the sense lead, which would likely require cutting the existing lead. Of course whatever you build would have to be safe up to 12000 Vrms. I wouldn't bother extending the 5205A cable, but rather have the mountain (DUT) come to the 5205A.

author: srb1954
author_rank: Super Contributor
timestamp: October 29, 2022, 03:18:18 am
content: Quote from: alm on October 28, 2022, 05:52:32 pmDo you really need to use low thermal EMF parts in this application?Presumably you are mainly calibrating AC instruments with the 5200A and these would be AC coupled and would ignore spurious thermal DC voltages. Even if you were calibrating a DVM with a TRMS AC+DC mode the impact of a few uV of thermal EMF would be negligible compared to other errors encountered in low-level TRMS measurements.

author: bdunham7
author_rank: Super Contributor
timestamp: October 29, 2022, 03:58:02 am
content: I don't have a 5200A around anymore, but I simply used BNC/RG58 cables and banana-to-BNC adapters at the ends. I still use the same cables with a lower frequency (50kHz) calibrator and, without one adapter, the wideband calibrator function on the 5100B. Well, not so much the latter anymore as it is actually not that good compared to an AWG.
Relative humidity calibrator and dew point meter with probe available - Page 1
Forum section: electronics / general

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: October 28, 2022, 06:09:30 pm
content: For sale Edgetech Instruments RH CAL relative humidity calibrator and a Vaisala DM70 dew point meter with a DMT152 probeItems are in excellent condition (actually like new), they appear to be fully functional from what I can tell. They come with manuals and various bits.Please PM me for more photos and discussion of pricing.https://edgetechinstruments.com/product/portable-relative-humidity-calibrator/https://www.vaisala.com/en/products/instruments-sensors-and-other-measurement-devices/instruments-industrial-measurements/dm70https://www.vaisala.com/en/products/instruments-sensors-and-other-measurement-devices/instruments-industrial-measurements/dmt152
MOVED: Getting acquisition dumps / Reading DAV files [from Multimetrix 2025 DSO] - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: December 01, 2022, 12:58:48 am
content: This topic has been moved toTest Equipment.https://www.eevblog.com/forum/index.php?topic=353315.0
Photo back side A2 board Fluke 5440B/5442A - Page 1
Forum section: electronics / general

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 20, 2022, 04:23:38 pm
content: Does anyone have a photo of the back of the Fluke 5440B/5442A A2 board?

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 21, 2022, 08:59:51 am
content: If there are difficulties with the A2 board, maybe someone will tell you about the memory module?According to the description, there can be two types of memory chips in the memory module. Is the module wiring preserved?In the module that I have, pins 4 and 24 are not connected. But on the A2 board they are connected. Perhaps there is some other type of module?
Shielded  cable for Low thermal EMF connectors - Page 1
Forum section: electronics / general

author: opa627bm
author_rank: Regular Contributor
timestamp: October 13, 2022, 08:48:35 am
content: Hi All,I ended up with Fisher connector on my Solartron DMM, it was in the USMC general equipment program and calibrated before I was born, but seems it is holding 0 really well. Now I need to make a cable for it.I also have the HP terminal block and low thermal EMF spade connector. I also need to make cables for it.I am looking for a 5 solid copper core cable that is good for low level measurements (Sense -+ Input -+ and current +). anyone have experience with it ? is sold core better than the multi-strand wire ?also any good crimping tool for those spade lugs ?Thank you!regards,Li

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 13, 2022, 01:48:19 pm
content: Apparently Cat5e network cable is a good budget choice.

author: alm
author_rank: Super Contributor
timestamp: October 13, 2022, 05:25:13 pm
content: You'd probably want a shielded PTFE-isolated 5-wire cable, but I'm not sure how common they are. 2 and 4 wires are common. Maybe you could do something with a 4 wire cable for voltage / resistance and from the same connector a 2 wire cable for current?I'd use stranded cable. Is much more flexible and easier to work with.I have used low thermal spade lugs and cable fromab-precision(user ap here). I use a Knipex crimper withthese dies. No guarantee they will work with other spade lugs, obviously.

author: laichh
author_rank: Regular Contributor
timestamp: October 14, 2022, 09:19:31 am
content: Shielded Teflon (PTFE) with Silver-Plated Pure Copper (SPPC) conductor is what you need, we use Belden 833xxE series here in our lab.

author: martinr33
author_rank: Frequent Contributor
timestamp: October 18, 2022, 02:21:58 am
content: The newer Fluke precision cables use 22AWG ptfe (black) and gold plated spade connectors.Also, Fluke sleeves the exposed wires in silicone rubber tubing. The silicone covered leads are very flexible, more so than I can get them, even with stripping the PTFE and untwisting the wire before adding the sleeving.That flexibility also tells us that the wire is stranded, not solid.

author: sahko123
author_rank: Frequent Contributor
timestamp: October 18, 2022, 09:09:54 am
content: 4 wire teflon insulated cable would be just as good and then a separate guard wire.Solid core Cat5e is what I use with copper spades
34410A Calibration question - Page 1
Forum section: electronics / general

author: opa627bm
author_rank: Regular Contributor
timestamp: October 15, 2022, 05:28:38 am
content: I am trying to adjust 2 34410A that was calibrated back in 2014, during the AC flatness adjustment, it seems I cannot get the read out to match the calibration value. is that normal?https://youtube.com/shorts/BFdKmX4rV20?feature=share

author: alm
author_rank: Super Contributor
timestamp: October 15, 2022, 09:06:19 am
content: I've never calibrated this meter, but it's a flatness adjustment, so something is adjusted in this process to maximize the flatness from 10 Hz to 1kHz. I could imagine that does not mean having to be spot on at all frequencies, but rather minimize the error across the range.If you complete and save AC voltage adjustments including the the low frequency AC flatness and normal AC flatness steps, does it comfortably meet the 24h specs in the AC voltage performance verification tests the service manual tells you to run after adjustment, and in particular the optional AC voltage tests that also test low frequency flatness?The adjustment procedure is to supply a value, enter the actual value and wait for the succeeded message. It does not tell you to verify that it reads any particular value. That comes later in the performance verification with different signals.

author: opa627bm
author_rank: Regular Contributor
timestamp: October 15, 2022, 09:17:39 am
content: Thank you for the reply, I will run the verification tomorrow. Since I only have two of this meter, I was too lazy to write a script for it, but for the flatness adjustment, there are ~ 100 steps total, so I probably should automate it.Also, For the DCA adjustment, in the high current range, (1A and 2A) the read out will shift for 15 min before stabilize (assume is the CSR heat up causing drift) , so do you do spot calibration or you wait 15 min for each step ?

author: alm
author_rank: Super Contributor
timestamp: October 15, 2022, 09:33:53 am
content: You could try just the 1V and 10V 10 Hz and 1kHz ACV performance verification points after saving the AC gain and LF flatness. The service manual is a bit unclear here: it tells you run ACV performance verification after LF flatness, and then again after normal flatness. But obviously testing frequencies above 1 kHz after just the LF flatness adjustment doesn't make sense.I don't see anything about it in the calibration manual, but I would wait for thermal stabilization in the higher current and 1000 V ranges. How long this takes depends on the meter. You could take a number of successive samples from the meter, or make a plot if it has a graphical display (e.g. 3446x/7x). If there's a clear linear trend in those samples, then I'd argue the system is not stable yet.
Tektronix ASIC + chunky FPGA on ebay - Page 1
Forum section: electronics / general

author: daqq
author_rank: Super Contributor
timestamp: October 14, 2022, 06:30:48 am
content: Found this:https://www.ebay.com/itm/115556000019?mkevt=1&mkpid=0&emsid=e11000.m88246.l9734&mkcid=7&ch=osgood&euid=980f6f8ab35449d2be712d5b6c8947f5&bu=43889533236&exe=0&ext=0&osub=-1%7E1&crd=20221013232601&segname=11000Wondering if it might be of use to someone (or at least for decapping and posting interesting imagery onto the forum), or at least a better use than someone extracting the seven milligrams of gold out of it?

author: Kleinstein
author_rank: Super Contributor
timestamp: October 14, 2022, 11:20:30 am
content: With the rather modern chips there is not much to see with a normal microscope. The FPGA structures are just to fine and would need a SEM, AFM or similar.

author: zrq
author_rank: Frequent Contributor
timestamp: October 14, 2022, 01:02:43 pm
content: If some one in the Europe can decap them, I'll be happy to do some SEM
DMM7510 0V Short Offset issue - Page 1
Forum section: electronics / general

author: opa627bm
author_rank: Regular Contributor
timestamp: October 12, 2022, 02:29:27 am
content: Hi All,We have 3 units on site for evaluation, 1 is freshly cal , 2 are not calibrated.both display about -4uV with a low thermal EMF short installed.We then inserted the short (34172b) to the 2 units that are not calibrated, let it sit for 1 day then we ran through the DC cal step 0 - 3.However after cal, the 2 units are still at -4uV when short is installed.this is giving me 0.5% error at 1mV input.Anyone having ideas if this is normal?Regards,Li

author: laichh
author_rank: Regular Contributor
timestamp: October 12, 2022, 05:33:08 am
content: The input terminal of the Keithley DMM7510 is not thermal e.m.f. treated, i.e., not pure copper like Keysight 34470A.My solution for your case would be just simplyNULL(orRELative in Keithley terminology) it.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 12, 2022, 09:29:32 am
content: Quote from: opa627bm on October 12, 2022, 02:29:27 amYou must abandon the 10 MΩ mode. And turn on the input impedance Auto.Other bugs and features of this miracle of technology are here:https://www.eevblog.com/forum/testgear/all-about-keithley-dmm7510-bugs-and-features-recipes-advice-notes/

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 12, 2022, 09:31:26 am
content: Quote from: laichh on October 12, 2022, 05:33:08 amI will say even more. The input terminals are at different temperatures( But in this case the problem is the 10 MΩ input impedance which needs to be disabled and never used again.

author: HighVoltage
author_rank: Super Contributor
timestamp: October 12, 2022, 01:44:57 pm
content: Very interesting, MegaVoltIt definitely makes a big difference, if the input impedance is set to 10 MΩ or AUTOI tested this on my two instruments:10 MΩUnit 1: 4.5 uVUnit 2: 6.3 uVAUTO:Unit 1: 0.03 uVUnit 2: 0.3 uVSee pictures

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 12, 2022, 02:05:27 pm
content: Quote from: HighVoltage on October 12, 2022, 01:44:57 pmFor 100mV range, 3-5uV error is 30-50ppm which is out of specificationI have no way to check the kind of error. Is this an error near zero? Or is it an additive error?

author: opa627bm
author_rank: Regular Contributor
timestamp: October 13, 2022, 08:50:38 am
content: That seems to fix the issue, now my 0 holds at 300nV Avg.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 13, 2022, 09:36:33 am
content: Quote from: opa627bm on October 13, 2022, 08:50:38 am300nV is a good value. If you need to reduce it even more, use Rel. The device keeps zero very well with auto-zeroing.
$72.54 for the Amazon Commercial 50,000 count DMM  - Page 1
Forum section: electronics / general

author: Switronic
author_rank: Newbie
timestamp: October 11, 2022, 11:35:58 pm
content: This thing is 50000 counts, TRMS, IP67, CATIV 600V, and has logging. Says its a 75% off deal. I'm guessing some dimwit forgot to type a 2 before 72.54. Tell me if I'm missing something lol.Anyway here's the link just thought I would share it.https://www.amazon.com/gp/product/B07VX431NK/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

author: xrunner
author_rank: Super Contributor
timestamp: October 12, 2022, 12:12:20 am
content: Tempting. Looks like it's a rebranded CEM DT-989https://www.cem-instruments.com/en/product-id-891It's $342 on aliexpress.

author: Switronic
author_rank: Newbie
timestamp: October 12, 2022, 12:38:51 am
content: According to a review, it indeed is a rebranded CEM DT-989. A CEM DT-989 is $329 with shipping on Amazon.Apparently the price is so good on the the Amazon DMM that it's already sold out...
HP 3458A firmware revision differences - Page 1
Forum section: electronics / general

author: matthuszagh
author_rank: Frequent Contributor
timestamp: October 11, 2022, 04:46:37 pm
content: I opened up my HP 3458A to replace the RIFAs and Schaffner filter. Because the instrument is already open, I'm thinking of taking this time to update the firmware. My unit has revision 7, but the latest is 9 (FYI, all firmware revisions are very helpfully listed here:https://xdevs.com/fix/hp3458a/#firmware). Is there a benefit to updating to revision 9? Are there any resources for how the various firmware revisions differ from one another?

author: Dr. Frank
author_rank: Super Contributor
timestamp: October 12, 2022, 08:56:18 am
content: Service note 12 contains descriptions of most of the Firmware updates.Ver 7 to 8 fixes this very old PERIOD calibration bug, which I already found in 1990 on my first 3458A.Therefore, it is reasonable to update to 8 or 9.Ver. 9 only changes timing of one of the ACAL procedures, so you should use this latest version.Check if you have a 6 EPROM board, or already the single EPROM one. I wonder if Illya also hosts latter version.Also check the date code of the nv-SRAMs, whether they have to be replaced soon, at least make a download of the CALRAM.Frank
Rs components Europe calibration service - Page 1
Forum section: electronics / general

author: NaxFM
author_rank: Regular Contributor
timestamp: October 04, 2022, 02:16:37 pm
content: Distributor RS components has a calibration service for all sorts of test equipment.I just received a quote of 220 euro VAT included for an accredited calibration for a 34401A multimeter, which includes full instrument adjustment in case something is out of spec.The quote is about the same as some local labs asked me, but it includes the free adjustment which is a very big deal.Do you have any experience with their calibration service? If so, what did you have calibrated and how the certificates look like?Edit: they also offer non accredited calibration certificate, in this case the quote is 190 euro VAT included

author: Andreas
author_rank: Super Contributor
timestamp: October 05, 2022, 04:26:57 am
content: Hello,not here in germany. They recommend to send devices for re-calibration to their partner TESTO (which is a larger cal-lab here).with best regardsAndreas

author: mendip_discovery
author_rank: Super Contributor
timestamp: October 05, 2022, 08:17:01 pm
content: At the time of writing (Oct 2022) RS UK does it for £120/90 not sure if that with or without VAT.I have seen their certs and they are ok. If it's a ILAC + 17025 lab than the quality should be fine. If you are chasing the part per butterfly then you will have to compare their Uncertainties with the other labs to make sure you are getting the best deals.It's also not uncommon for most labs to do minor adjustments as part of the Calibration. Expect before and after results if they do.

author: Villain
author_rank: Regular Contributor
timestamp: October 07, 2022, 05:18:04 pm
content: Quote from: mendip_discovery on October 05, 2022, 08:17:01 pmI had quite the laugh at "If it's a ILAC + 17025 lab than the quality should be fine"In my humble opinion only UKAS and NVLAP have good quality standards, A2LA is worst and ANAB not much better. Can not say much about Asia's accreditation bodies.

author: mendip_discovery
author_rank: Super Contributor
timestamp: October 07, 2022, 05:44:01 pm
content: Quote from: Villain on October 07, 2022, 05:18:04 pmI am under UKAS and we all work with the same standards partly stewardship covered by ILAC so its disheartening that it's not the same the world over. But who audits the auditors etc.