hybridfree/eevblog-posts huggingface dataset:
732B other stuff on the certificate  - Page 1
Forum section: electronics / general

author: mendip_discovery
author_rank: Super Contributor
timestamp: February 25, 2024, 06:54:02 pm
content: So I might have a 732B coming in for me to measure. From what I can tell is a serious hobbyist. Just making use of a local lab.So other than measuring the voltages and supplying a measured reading I am wondering what else I can also put on the certificate that a volt nut would like to know. It is not a 17025 certificate so I have some leeway.I was thinking of leaving it to measure over a weekend. So adding some data on voltage stability and the internal temperature sensor readings. I will supply him with the logged data if he wants it.I will be using the 3458A and with luck within 90 days of calibration to use the lower spec of the 002 option. ~34 µV k=2 (95.45%) at 10 V. But it is out at the moment being calibrated.

author: alm
author_rank: Super Contributor
timestamp: February 25, 2024, 08:50:00 pm
content: If you have the ability to measure relative to a calibrated voltage standard like another F732B, that would provide a lower uncertainty. I think the uncertainty of the 3458A is going to be the dominant factor here. Regarding stability, if anything the F732B should test the 3458A's stability, but monitoring and looking for anomalies certainly wouldn't hurt.One thing that might help the hobbyist (depending on how serious they are) is provide them with the data from the 3458A calibration, like the measured value, calibration uncertainty and the expected value (= (lower limit + upper limit) / 2. This will allow them to calculate the correction factor for the 3458A. I don't know if this is allowed by the relevant standards, but it's something I as hobbyist use to get a more accurate measurement. For example I did thatat Metrology Meet 2022based on the certificate for branadic's 3458A. My calculations there also yielded a 34 uV uncertainty based on the actual calibration uncertainty and published specs (k=2).

author: mendip_discovery
author_rank: Super Contributor
timestamp: February 25, 2024, 09:00:53 pm
content: Yup, I may well give them the info from the calibration certificate.I have personally some 10V sources (ltz) that should be handy as a transfer standard. I plan plan on getting the lab I use to measure one at some point as an interlab type check.

author: alm
author_rank: Super Contributor
timestamp: February 25, 2024, 09:25:07 pm
content: I would measure the reference both polarities (to correct for thermal EMF in cables and any offset in the meter). I prefer to swap cable at the reference, but be sure to give time for any temperature gradients caused by your hands touching the binding posts to dissipate.Be careful about the guard connection. Either connect guard properly and connect it to F732B guard and short it to where ever the negative cable from the 3458A connects per HP AN-123 (seethis illustration) and set the guard switch on the 3458A to open (best common mode rejection), or don't connect the guard at all and set the guard switch to LO. But don't set the switch to LO and then connect the guard at the reference end.
Calibrating a Keysight 34461A - Page 1
Forum section: electronics / general

author: kkayser
author_rank: Contributor
timestamp: February 25, 2024, 05:21:08 pm
content: I am attempting to calibrate my 34461A:1. Update firmware2. Connect 732B3. Set range to 10 volts4. push "perform cal step" works but meter reading does not change.5. push "perform ADC cal" error message: 708 calibration error, signal measurement out of range.
Keysight 34461A, update frimware. - Page 1
Forum section: electronics / general

author: kkayser
author_rank: Contributor
timestamp: February 24, 2024, 06:37:46 pm
content: My attempt to update the firmware in my 34461A.1. Download frimware update zip file.2. Extract all zipped files --> one file *.upd3. Copy file to thumb drive and place thumb drive in 34461A front USB receptacle4. Press update firmware button --> error message "file not found".What am I doing wrong?

author: wraper
author_rank: Unknown
timestamp: February 24, 2024, 06:48:27 pm
content: For using .upd you need to install their utility. To directly copy the files you need "Firmware Update for Non-Windows Operating Systems"https://www.keysight.com/us/en/assets/ndx/9921-02960/instrument-firmware-software/34461A-V3-03.zipInstructions:https://www.keysight.com/us/en/assets/9018-07477/release-notes/9018-07477.pdfAlso if you have 1.xx firmware, you need to update to 2.17 first.

author: kkayser
author_rank: Contributor
timestamp: February 25, 2024, 04:56:35 pm
content: Thank you. After a bit of fiddling and getting rid of a defective thumb drive, I got oi to update.
"Fluke 732A - ripple on output" (link to main thread) - Page 1
Forum section: electronics / general

author: Rax
author_rank: Super Contributor
timestamp: February 25, 2024, 02:48:04 am
content: In the spirit of avoiding cross-posting, here's a link to my latest repair project. I think this gang (y'all) is the fitting demographic for this (and most of my) projects, but it is a "repair," so...https://www.eevblog.com/forum/repair/fluke-732a-ripple-on-output/
eBay scored new meter!! - Page 1
Forum section: electronics / general

author: Hullen
author_rank: Contributor
timestamp: February 27, 2024, 12:34:52 am
content: Hey guys, I’m new here. I’m a heavy equipment mechanic, tool junkie and meter hoarder. Anyways I just scored a new in box TPI 192-II on eBay for 50$. I wanted one of these for a while and still want to get a TPI 196-II. At 50$ I feel like this is a score
Synergy SSR - Page 1
Forum section: electronics / general

author: mojoe
author_rank: Frequent Contributor
timestamp: February 06, 2024, 08:39:51 pm
content: I thought this would be the best sub forum for my question, as Time Nuts and wantabes hang out here.I have a Synergy Systems SSR board with a LEA-8T on it. The SSR board I have emulates an old Motorola GPS and sits on an adapter board that fits where a Motorola UT Oncore would go. I bought this years ago for a Z3801, but never used it.I have installed the demo version of SynTac and hooked up the SSR w/adapter to a USB/serial board. SynTac sees the SSR as a Motorola GPS.When I go to the menu Edit - Set GPS Receiver Interface, I can change it from Motorola Binary to u-blox UBX. The raw data output from the GPS shows that it did switch to UBX format.My question is, how can I make this switch permanent, so that the SSR always powers up in UBX mode? I want to use this nice LEA-8T elsewhere.

author: testpoint1
author_rank: Frequent Contributor
timestamp: February 17, 2024, 03:10:58 am
content: Quote from: mojoe on February 10, 2024, 01:14:04 pmI have many LEA M8T and M8F, if you need, you can refer here:https://www.ebay.com/itm/186178722941,I can swap with you.

author: mojoe
author_rank: Frequent Contributor
timestamp: February 23, 2024, 07:42:29 pm
content: Never Mind. Traded board.
High performance digitizer and DC metrology meeting, 19th February 2024 - Page 1
Forum section: electronics / general

author: jaromir
author_rank: Unknown
timestamp: February 17, 2024, 05:53:25 pm
content: Hello folks,sorry for being late with this news, but in a few days High performance digitizer and DC metrology meeting takes place in Bratislava, Slovakia.For those who can't join in person, online access is possible.https://indico.cern.ch/event/1357615/

author: RandallMcRee
author_rank: Frequent Contributor
timestamp: February 19, 2024, 12:34:39 pm
content: Can a recording be made available?Thanks,Randall

author: miro123
author_rank: Frequent Contributor
timestamp: February 19, 2024, 01:13:24 pm
content: I just sow this message.It is shame that I cannot participate the meeting - registration is already closed. I hope that website will provide some material or recorded video afterward.BR,Miro

author: Okertime
author_rank: Contributor
timestamp: February 19, 2024, 03:49:11 pm
content: I could not find a way to get the meeting passcode to join the video conference - frustrating

author: iMo
author_rank: Super Contributor
timestamp: February 19, 2024, 06:27:34 pm
content: Jaromir and the team,my thanks for the great opportunity to meet with Nikolai, Rado, You and others in person as well as Luis online during the meeting! Nice event!And my big thanks to Rado for giving me his signature on the title page of his book!!
keysight 34461A.firmware release in meter - Page 1
Forum section: electronics / general

author: kkayser
author_rank: Contributor
timestamp: February 23, 2024, 05:49:50 pm
content: Does anyone know how to determine the firmware release which in in the meter?

author: HighVoltage
author_rank: Super Contributor
timestamp: February 23, 2024, 05:53:02 pm
content: You mean to view the installed version?Just go to the "About" screen in the help section

author: EC8010
author_rank: Frequent Contributor
timestamp: February 23, 2024, 09:38:06 pm
content: Be careful about installing new firmware on 34461A. I had a problem with a 34470A that Keysight said would be cured by installing the most up to date firmware. So I did, and it worked. Emboldened by this success, I thought I ought to update the firmware on my two 34461A. The Keysight 34461A was perfectly happy, but the (final generation) Agilent promptly stopped working. I informed Keysight and it took time before they accepted responsibility for incompatible firmware (NOT mentioned on the download), collected the meter, fixed, and returned it. Admittedly, it was all done FOC, but there was a lot of hassle involved and it shouldn't have been necessary.In short, it's only really worth updating firmware that works if the new firmware has something you genuinely need or the existing firmware has a bug that causes you trouble.
1/f noise of Fluke 8588A in comparision to HP 3458A - Page 1
Forum section: electronics / general

author: Sphyrna
author_rank: Contributor
timestamp: February 09, 2024, 11:02:20 am
content: Hello,I would like to ask if someone can provide some measurement data of a Fluke 8588A with the following settings for me:mode: DCVrange: 100 mVaperture: 1 sref. freq.: 50 Hzinput: shortduration: 24hI would like to perform a fft with the data to do a comparison with two HP 3458A I have here (close to arXiv:2205.11321v1).

author: AVGresponding
author_rank: Super Contributor
timestamp: February 09, 2024, 01:08:43 pm
content: You might be better off posting this in theMetrologysection.

author: Sphyrna
author_rank: Contributor
timestamp: February 09, 2024, 02:15:26 pm
content: Could a mod please move it to metrology?

author: lpal
author_rank: Newbie
timestamp: February 16, 2024, 10:50:27 am
content: Have a look herehttps://arxiv.org/abs/2205.11321

author: Sphyrna
author_rank: Contributor
timestamp: February 19, 2024, 06:49:58 am
content: This was the publication I linked in my first post. You could estimate the results for my settings but I would prefer a real measurement.
Symmetricom SyncServer S200 - Not syncing from GPS - Page 1
Forum section: electronics / general

author: suresh5star
author_rank: Newbie
timestamp: December 26, 2023, 06:53:33 am
content: I have two SyncServer S200 which was working fine and acting as Stratum 1. Since last few months it's showing as stratum 3. GPS status looks good and I can see around 10 satellites in GPS tab. Why it's still showing as Stratum 3 instead of Stratum 1?

author: JoeFloyd
author_rank: Contributor
timestamp: February 17, 2024, 10:51:46 am
content: This short answer is that the GPS receivers have experienced a GPS week rollover bug and no longer report the correct date.If you search on-line you can find replacement GPS receivers which will fix the problem. These GPS receivers are somewhat specialized and the ones used in the S200 are a specific form factor and use a Motorola specific protocol for communications.An example of a compatible GPS receiver is:https://prostudioconnection.com/collections/gps-receivers-clocks/products/symmetricom-syncserver-xli-gps-no-sync-wnro-fix-replacement-m12-receiver-new-newAnother is a GPS receiver called iLotusOne that was recently discovered by a forum member is the HEOL GPS reciever.https://www.ebay.com/itm/134842120193.This receiver is cofirmed to work in the S200.

author: testpoint1
author_rank: Frequent Contributor
timestamp: February 19, 2024, 12:58:02 am
content: Quote from: suresh5star on December 26, 2023, 06:53:33 amI will orgnize some Motorola M32 module, fast searching, no 1024 week rollover problem.
Very high permeability cores free to a good home - Page 1
Forum section: electronics / general

author: Sengcid
author_rank: Regular Contributor
timestamp: January 14, 2024, 07:56:49 pm
content: I have a number of Telcon size 12C (large) cores (perm > 200,000) to give away. Anybody fancy having a go at a DC current ratiometer using the fluxgate null detector technique (c.f. Guildline 15ppb DC resistance bridge)? Pls pm if interested.

author: Echo88
author_rank: Frequent Contributor
timestamp: January 15, 2024, 01:42:18 am
content: How would you go about realizing the null detector with an existing core as this needs a very special construction technique?It should be possible to build a DCC-bridge by rewinding an existing DCC transducer (with already present zero flux core) like the Ultrastabs/Danfysik ones available used on ebay. Ive never continued this project though.Happy to see if i can infect someone with the idea, who then realizes it

author: Sengcid
author_rank: Regular Contributor
timestamp: February 09, 2024, 08:35:06 pm
content: I am having problems with the PMThe cores are SM200. See atttached.
Magnetic sensor characterization techniques - Page 1
Forum section: electronics / general

author: Guille
author_rank: Regular Contributor
timestamp: February 08, 2024, 04:28:01 pm
content: Hi everyone,We are a team of researchers collaborating with another team that produces magnetic sensors (AMR and TMR Wheatstone Bridges) we are tasked with characterizing said sensors but since we are physicists this area is not our forte. I'm therefore looking for good resourcess on sensor characterization (magnetic sensors if possible), how can one find what the industry standard for this task is? Experimental setup, proceedings, figures of merit...If hard to find books, lectures, application notes, etc are great recommendations too.Thank you for your time!

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: February 08, 2024, 06:22:37 pm
content: I don't know if there are general standards. When I've had to characterize magnetic sensors I use a stepper driven stage (Velmex or similar) and mount the sensor or magnet on the stage. I write test programs to sweep the sensor past the magnet (or rotate if that's what you need) and collect data at whatever increments are needed. There are some tricks you can use like opposed magnets to create a narrower field. Honeywell had a useful book on hall effect devices that you can download here-https://www.rsp-italy.it/Electronics/Databooks/Honeywell/_contents/Honeywell%20-%20Hall%20Effect%20Sensing%20and%20Application%201998.pdf

author: Guille
author_rank: Regular Contributor
timestamp: February 09, 2024, 10:21:29 am
content: We tried measuring Sensitivity and Detectivity of commercial sensors however these measurements differed greatly from the datasheet specs which makes me wonder if we are doing something wrong and thus are not ready to characterize the sensors our colleagues are developing

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: February 09, 2024, 01:41:30 pm
content: It's nice to have a reference point- do you have a gaussmeter? I use an F.W. Bell unit that's decent as they have some tiny probes that suit my tiny projects.

author: 3roomlab
author_rank: Frequent Contributor
timestamp: February 09, 2024, 03:27:11 pm
content: what about making the helmhotz coil ?like using it to transfer a referencea known unit can measure itand then the unknown unit ?
MULTIMETER AMECAL ST-9905 - Page 1
Forum section: electronics / general

author: lionelkjh
author_rank: Frequent Contributor
timestamp: February 06, 2024, 05:17:20 pm
content: Good evening everyone!! I'm looking for someone who owns an AMECAL ST-9905 multimeter, and I need fairly large photos of the board (component side) of the entire multimeter... A big thank you to anyone who can give them to me... Thanks in advance!!

author: lionelkjh
author_rank: Frequent Contributor
timestamp: February 07, 2024, 09:00:39 am
content: Good morning; I specify that only detailed photos of the card suit me without dismantling everything (display and switch)....Thank you for your cooperation

author: lionelkjh
author_rank: Frequent Contributor
timestamp: February 08, 2024, 10:06:31 am
content: Good morning; no one has this multimeter??

author: mendip_discovery
author_rank: Super Contributor
timestamp: February 08, 2024, 05:59:34 pm
content: The people over in the Test Equipment area might be more willing to owing up to owning this, or ask I repair.Here in the Metrology area we are snobs and sneer at anything less than 5.5 digits. :-)

author: lionelkjh
author_rank: Frequent Contributor
timestamp: February 11, 2024, 02:40:40 pm
content: Good morning; very cooperative and very informative!
Resistor size / cross section versus low current any effects ? - Page 1
Forum section: electronics / general

author: Overspeed
author_rank: Frequent Contributor
timestamp: February 03, 2024, 10:22:54 am
content: HelloI am in process to built a set of low values resistor in the 0.001 Ohm rangeMy 0.001 lab reference is able to handle more than 30 amp ( 50 max ) and inside the box that a thick foil of I suppose in manganin , I have another one 0.003 which have that same design except the big foil is flat as in a Vishay foil resistorI have also Vishay shunt 4 wires as WSLP4026 size shunt so far smaller in size rated to 3 WMy question base on the fact the raw material is different so resistivity is different = OK , but does the cross section of resistor and the mass of the resistor have or will have an effect on low current measurementI measure DC and 70Hz AC voltage in the range between 10 ma and 50mAAs I will run calibration accuracy as true value '' 0.000X0000 '' is not a concern I can work with real measured values during calibrationMy goal is to built a setup ( resistor box ) to measure the resistivity of metal and I want to built a reference but I prefer check before as feed a '' big resistor size '' with only 10 mA looks strange compare to 30 Amp and more resistor and I dont locate any articles ob this particular subjectRegardsOS

author: Overspeed
author_rank: Frequent Contributor
timestamp: February 05, 2024, 03:43:38 pm
content: HelloI have now a far better understanding of resistor technologies and physic after to have read this bookRegardsOS

author: branadic
author_rank: Super Contributor
timestamp: February 05, 2024, 10:28:51 pm
content: There is a copy available onxdevs.-branadic-
NIST resistor calibration document PDF  - Page 1
Forum section: electronics / general

author: Overspeed
author_rank: Frequent Contributor
timestamp: February 05, 2024, 03:34:20 pm
content: HelloAn interesting reading from NIST in PDF with pictures and schematics / formulaRegardsOS

author: alm
author_rank: Super Contributor
timestamp: February 05, 2024, 04:17:40 pm
content: Note that the title is more specifically "High Voltage Divider and Resistor Calibrations". There are a number of other documents on low voltage resistor calibration. Here's a couple:Circular of the Bureau of Standards no. 470::precision resistors and their measurement (1948)/url]NIST Technical Note 1298: NIST Measurement Service for DC Standard Resistors (1992)Automated Resistance Measurements at NIST (1995)NIST Technical Note 1458: NIST Measurement Service for DC Standard Resistors (2003)
Trimble thunderbolt TSIPCHAT questions - Page 1
Forum section: electronics / general

author: 5065AGuru
author_rank: Frequent Contributor
timestamp: February 01, 2024, 08:38:40 pm
content: Hi, I have a Trimble thunderbolt.I have used thee thunderbolt monitor program to look at it's operations but I'd like to issue some commands.I downloaded the TSIPCHAT program and ran it (win 98) using cmd prompt and TSIPCHAT -c1 for com 1A screen comes up but it appears that I'm not communicating with the unit.inputting ? gives a list of commands but except for the first column they are grayed out.Any hints on how to get talking would be appreciated!Cheers,Corby
solartron 7075 - Page 1
Forum section: electronics / general

author: p.larner
author_rank: Frequent Contributor
timestamp: January 30, 2024, 05:48:14 pm
content: i have the solartron 7075,it has its inputs dead/deaf,does anyone know what board/pcb handles the input sampling?.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 30, 2024, 06:47:50 pm
content: There is a service manual with quite some description floating around.A first point to check is the supplies.Before looking at the ADC I would check the input amplifier, as this should be relatively easy.The solartron meter is using a chopper stabilized input amplifier, with an LDR based chopper and discrete JFET based fast amplifier part.The meter is not really using sampling, but integration at the input. So the readings are the avearge over a certain time (e.g. 1 second).For the ADC a good test point is the integrator output, to check if the expected waveform is present.
Solartron/Schlumberger7060 Repair - Page 1
Forum section: electronics / general

author: DVM-James
author_rank: Contributor
timestamp: January 30, 2024, 05:31:18 pm
content: Got this old toy some weeks ago. It works fine for some hours. But one day the display was dark - selftest didn´t run.So I carefully broke the original solartron-seals and opened the covers. Measuring the powersupply-voltages, I found the +15 V at +21 V !The 7815-regulator was gone. After replaced it, the Selftest was o.k. so far. After "GBIB OFF" only two bars were on the left side.So I had to explore a little bit around and overcross the diagrams and found the two loops around the integrator/comparators (ADC).To make it easier for me to get the right track to measure and following the loops, I did some drawings by hand and notes to understand how it works. ( or You can say: what was first - the egg or the hen ?) I found out, it would be fine to open the loops by removing the JFETs that normaly switches the + and - REF. and "ZERO". ( I removed the JFET TR204 for the -REF. only, because there was -8 V (static) on the summing-point TP203 / input of the integrator )( Got this hint on chapter 5 / page 2.31 ff into the service-manual for the7061/62! )Now the integrator started - showing some telefone-nos. on the display ( DC V-input shorted ). Measuring my selfmade track, I found my "friend" after a short time: IC 816A ( oscilloscope-picture shows an input "LOW" on pin2 on channel1 and the output pin12 or TP804 ("slave bistable clock" ) on channel2 - that was 600 mV only - not a good logic "HIGH" )After renewed the 74LS10: "machine was repaired"To make it a little bit easier for DYSers, hobbyists (and professionals ?), I made my drawings and measurements a little bit chic and have attached it here.As the most DMM from the Solartron70xx-series work so, it may be helpfull for repair anyway.I´ve also attached the bin-code for that 2532-EPROM ( checksum : 5DA00 hex ).btw.: It´s a 7060G - so the AC-RMS-Volt/Amp.-option is mounted. It would be interesting to get some information regarding the AD6024-RMS-hybride. ( data-sheet ) I couldn´t find anything about it.For now - best regards + have a nice time.

author: DVM-James
author_rank: Contributor
timestamp: January 30, 2024, 05:39:21 pm
content: - and one missing attachment !
Efratom MRK Rubidium Standard Module.......  - Page 1
Forum section: electronics / general

author: Smokey
author_rank: Super Contributor
timestamp: January 29, 2024, 03:50:14 am
content: I scored a Efratom MRK 101656-012 Rubidium Standard Module (1997 vintage) on the cheap from a swap meet junk bin recently.https://www.tzsupplies.com/ball-efratom-mrk-101656-i4098269/It's supposed to go in a rack like this:https://www.febo.com/pages/efratom_mfs/https://www.febo.com/pages/efratom_mfs/mfs.pdfUnfortunatly I only have the MRK Rubidium module and none of the other rack. The module only has that big multi-way backplane connector on the back, and that's it. The front panel has some BNCs but it sort of looks like the output is distributed through the backplane for the other cards.You can get a whole rack system for like $600 from ebay.https://www.ebay.com/itm/364067614125Anyone played with one of these?Should I try to figure out what's going on with the backplane connector or just skip it and tear the enclosure apart and try to interface with the components directly?

author: edpalmer42
author_rank: Super Contributor
timestamp: January 29, 2024, 05:24:37 am
content: I'd pull the FRK and test it seperately.It was available with two connector styles - seperate pins or a three row Winchester-style connector. If you're lucky and got the version with seperate pins, it's trivial to make the connections. In fact, if you've a dead ATX power supply, the female jacks on the 24 pin, 6/8 pin, or 4 pin power connectors are a perfect fit. Carefully cut the connectors apart and you end up with nice, insulated single pin sockets.The full service manual for the FRK (including schematics and calibration info) is widely available online.If the FRK checks out, you can then decide what your next steps are. Personally, I'd just put the FRK into a new box with a power supply. Without the chassis and the other modules (i.e. power supply and output splitter/amp) the module doesn't have much else that's useful.Ed
A novice calibration question - Page 1
Forum section: electronics / general

author: gray5596
author_rank: Newbie
timestamp: January 23, 2024, 09:38:57 pm
content: A novice question.Using a stable 10 volt reference, I was checking the accuracy of two 5.5 digit multi-meters. One read slightly high, 10.0001 volts. The other read slightly low 9,9999 volts (occasionally flickering to 10.0000). Because the 1st meter was reading slightly high, I was able to get 6 digits of information but only 5 digits of information from the 2nd meter.To prevent this from happening,why aren’t common voltage references slightly higher?For example 10.1 volts would allow both meters to stay in the 6.5 digit mode and it would be easier to compare.I’m just curious.

author: Bud
author_rank: Super Contributor
timestamp: January 23, 2024, 09:42:11 pm
content: They would Not be references then

author: bdunham7
author_rank: Super Contributor
timestamp: January 23, 2024, 09:48:36 pm
content: Quote from: gray5596 on January 23, 2024, 09:38:57 pmAlthough 10.0001 does actually have 6 digits and 9.9999 only has 5, there's no real significance to that difference in terms of precision or how much "information" you have. You still have the same number of signficant figures after the decimal and the LSD (last digit) represents the same amount, 100µV per count.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 23, 2024, 09:59:17 pm
content: The actual resolution is still the same.A few meters may actuall only show a result of 10 V at the may or may even max out at 9.999 or so. For these meters it can actually be better to have a reference voltage a little lower than the rounded value.This is less an issue at 10 V, but can be a real point at some 2 V, with many meters having +-1999 counts. For this they have ref. voltages at 1.9 V and similar values with calibrators.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: January 23, 2024, 10:14:35 pm
content: The 10V reference is not really 10V sharp. It’s a zone, defined by the initial or calibrated accuracy, the long term and thermal stability, and the load regulation.To transfer calibration, your source should be better, I’d say by a magnitude, to have a meaningful ability to judge the accuracy of a target.How accurate is your 10V reference?

author: gray5596
author_rank: Newbie
timestamp: January 23, 2024, 10:39:12 pm
content: Thanks for all the answers and ideas.The 10 volt reference I was using was not anything spectacular, a AD587LN in a sealed case. It looks stable when warmed up and when measuring it using my HP34401A in the 6.5 digit mode.
Ratio transformer errors - Page 1
Forum section: electronics / general

author: bdunham7
author_rank: Super Contributor
timestamp: January 22, 2024, 12:08:59 am
content: I'm trying to sort out the AC performance on several meters and I have two ratio transformers, both Gertsch--an RT-6 and a PT-5R (essentially an RT-5 rearranged). I thought I noticed some discrepancies between the two and while I'm trying to quantify and demonstrate that, I had a practical question and a theoretical question about these ratio transformer.First, while the design of these and their specs seem to indicate that they will be quite accurate as long as you observe the operating parameters, what actual sources of error have you found with them in real-life situations? I'm driving them with either a 510A @ 1kHz or a 5100B-series calibrator with a calibrated reference meter on the input or output as the situation merits. The output load is 1-3 multimeters selected from a group of Fluke 8505A, 8506A, 8846A and 289.Second, although it is fairly easy to recite the various theoretical causes of error, what are the magnitude of these errors and can any of them cause the output to be higher than the input x selected ratio by any appreciable amount? It seems to me that all of the various causes that aren't totally negligible would only cause the output to be lower. That's important because it would mean that like mercury barometers, if there is a discrepancy between instruments the highest one is always the most correct.I've attached the specs for the RT-5, the RT-6 is the same except it doesn't have the potentiometer thus the resolution is 10ppm not continuous.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: January 22, 2024, 01:47:44 pm
content: Don't know if they address your concerns directly but there are two Henry Hall papers that might be of interest. One is on a different electrical model for ratio transformers and the other is on ppb measurements with them. They're probably buried somewhere on the IET Labs site and I have copies here. I'll try to find them in the next couple days if you can't.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: January 22, 2024, 08:38:17 pm
content: The Henry Hall ppb article is here-https://www.ietlabs.com/pdf/GR_Experimenters/1968/GenRad_Experimenter_May_1968.pdfHenry's model is here-https://www.electronicdesign.com/technologies/analog/article/21808689/a-better-transformer-equivalent-circuitThe GR1493 manual is also a must-read-https://www.ietlabs.com/pdf/Manuals/GR/1493%20Precision%20Deacde%20Transformer.pdf
Fluke/Wavetek 910R GPS Frequency Std - schematics wanted (5/10MHz output fails) - Page 1
Forum section: electronics / general

author: carl_lab
author_rank: Frequent Contributor
timestamp: January 24, 2018, 03:15:39 pm
content: Can somebody help me to find schematics for a Fluke 910/910R GPS-Controlled Frequency Standard, please?The 5 and 10MHz outputs are stone-dead (no signal). 1 PPS output is OK.+5V test pins at J910 (connector unpopulated/free) is dead (0.9V).+5V, -5.2V, 12V named test pins beside the GPS sub board are OK.TTL supply voltage is measured about 4.9V (OK).

author: carl_lab
author_rank: Frequent Contributor
timestamp: January 26, 2018, 07:37:10 am
content: OK, rubidium module does not deliver 10MHz output signal.Supply voltages seem to be OK.

author: NRP_SANTOS
author_rank: Newbie
timestamp: February 02, 2024, 03:23:21 pm
content: Hi Carl,I have the same problem on my equipment. Do you have a diagnosis?nrp_santos

author: NRP_SANTOS
author_rank: Newbie
timestamp: February 07, 2024, 02:27:40 pm
content: 22v is missing to power the oscillator. U901 breakdown.Change U901 UC3842AD (Controlador de comutação Current-Mode PWM Controller) and capacitor 100uf 50v.best Regards
Is there an interest in universal datalogger/scanner software for GPIB or RS232? - Page 1
Forum section: electronics / general

author: SanderMTI
author_rank: Contributor
timestamp: November 29, 2023, 10:58:15 pm
content: Hello, new member here.If you are anything like me, you will have old meters hanging around which have a GPIB or RS232 interface.For a project about valves (electron tubes) I needed to read a few different meters at the same time, and log the readings overa long period of time.Long story short: I wrote a full-featured app for Ulrich Bangert's EZGPIB environment which does what I want:- runs everything via USB from an XP laptop.- outputs into a .csv file for excel- up to 10 (or more) channels- can support all existing meters which produce a reading.- manual sampling, linear or exponential timed sampling, logs from seconds to months.I am currently putting the finishing touches on version2, which adds scanning outputs.This, because I wanted to get frequency plots from an audio analyzer, and add a sourcemeter to the setup.If there is an interest on this forum for something like this, I can post it or send you a copy.(free of course..)As far as I am concerned, it is all I will ever need for automated experimenting and testing.No Labview,EEVPRO,Matlab,drivers, excel macros, limits on capabilities, Windows10 or wasted time.My own software reads and scans everything I have just fine without any of the fancy expensive stuff.I suppose a list of tested instruments is in order, but as I said, it works with everything.Not only that, it works with everything at the same time.Audio Precision ATS-1 audio analyzer (frequency and / or amplitude sweeps)Fluke 199 scopemeter (RS232)HP (agilent, keysight..) 34410A multimeterHP 34401A multimeterKeithley 2400 source meter (voltage or current sweeps)Keithley 175 multimeterKeithley 199 mutimeterKeithley 6512 electrometerKeithley 2700 multimeterSolartron 7065 voltmeter (RS232)Schlumberger SI 7062 voltmeterEmail me if interested.Addendum:I have had some people ask me "Does it support my meter" ?That's the wrong question to ask, it's not about the meter, it's about the GPIB interface you use to talk to your meter.There are many different ones with many different software access methods.I use a Prologix GPIB-USB adapter and a generic USB to 4 or 8 COM port adapter.With that, I can read three RS232 meters and three GPIB devices at the same time.The EZGPIB environment can support other GPIB interfaces.To find out if yours is supported, download EZGPIB, run it and click "debug messages".This will open a window which will tell you if EZGPIB has found a GPIB interface it can work with.Sander

author: lern01
author_rank: Regular Contributor
timestamp: January 21, 2024, 02:17:22 am
content: Can you upload some pictures of you using it? Thanks!
Using integrator to measure capacitance - Page 1
Forum section: electronics / general

author: slugrustle
author_rank: Frequent Contributor
timestamp: January 23, 2024, 08:08:56 pm
content: Are there any capacitance measurement instruments that use an integrator to measure capacitance? The idea would be to use the unknown capacitor as the integrator capacitor, connect the integrator input to a very accurate current source, and measure the slope of the integrator output voltage. It's almost like the inverse or complement of a multi slope ADC.Granted, this would only measure capacitance at DC with 0V bias. I'm just curious if it has been done before or if there are reasons why it would be hard to make accurate. In particular, I'm thinking the integrator output voltage slope measurement might be tricky to perform accurately.On the other hand, if you want to measure a capacitor that is intended for use in an integrator, this would be a great way to do it, as opposed to an AC capacitance bridge or whatever.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: January 23, 2024, 09:02:31 pm
content: Can't name any specific instruments but I'm pretty sure some inexpensive ones work this way. It's not a bad method if you don't have much to work with but doesn't give you losses and is subject to DC leakage of the cap. Integrator capacitors can be sensitive to dielectric absorption; Bob Pease wrote some stuff on this.https://www.electronicdesign.com/technologies/analog/article/21796328/electronic-design-whats-all-this-soakage-stuff-anyhowhttps://www.edn.com/wp-content/uploads/2016/11/1982-10-13_EDN_Pease-capacitor-soakage.pdfhttps://www.electronicdesign.com/technologies/analog/article/21796004/use-analog-techniques-to-measure-capacitance-in-capacitive-sensorshttp://www.ecircuitcenter.com/Circuits/DMM%20Cap/DMM_cap_1.htmlhttps://www.metrohm.com/content/dam/metrohm/shared/documents/application-notes/an-e/AN-EC-012.pdfThose links should keep you off the streets and out of the pool halls for a while.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: January 25, 2024, 09:50:24 am
content: Many multimeters measure capacitance this way. They have a current source for changing resistors. If you apply it to a capacitor, you will get a measurement))For example DMM6500, DMM7510

author: tszaboo
author_rank: Super Contributor
timestamp: January 25, 2024, 10:11:56 am
content: You can build this. The biggest error source is the offset voltage in the system, that gets integrated, so you might need to compensate that out before each measurement, or use dual slope or other methods that are less susceptible for those errors.
Duh! Moment of the day - Page 1
Forum section: electronics / general

author: mendip_discovery
author_rank: Super Contributor
timestamp: January 05, 2024, 05:52:47 pm
content: Today I was calibrating one of those wand-like High Voltage probes and I used the 34401A as the measurement device for the output of the probe.For a while, I thought this probe was rubbish 20 mV out at just 200 V then when I tried 800 V and it gave me a not too dissimilar reading to 600 V I thought, I know what I might have done.10 MΩ vs the 1 GΩ on the input will mess with the maths of the voltage divider in the HV probe.https://www.farnell.com/datasheets/1992834.pdf The customer only uses it in low ranges, and I can't supply more than 1kV anyway.

author: bdunham7
author_rank: Super Contributor
timestamp: January 05, 2024, 06:05:55 pm
content: Quote from: mendip_discovery on January 05, 2024, 05:52:47 pmI always manual range to 100V when using these, otherwise there are multiple issues that can get you. IDK how you can calibrate it with 1kV since voltage nonlinearity is the big issue with these. And if your customer only uses it at low ranges, I hope his DMM doesn't have 11M input impedance in those ranges....

author: mendip_discovery
author_rank: Super Contributor
timestamp: January 05, 2024, 06:23:57 pm
content: Yeah its one of those off things, I think they just prefer the wand like probe for getting near to voltages.I have it on my list of things to make is a HV source and a voltage divider up to 10 kV as more than that starts to get into the dangerous stuff that I really don't want to play with. I think I might keep an eye out for an old Flash Tester I could use for the source.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 05, 2024, 07:44:04 pm
content: With a 1:1000 divider and 1 Gohm for the input the output resistance for a simple divider would be around 1 Mohm. This would imply some 1.1 M internal to be supported by 10 M from the DMM.So I don't see why it should make that much difference if the meter is 10 M, 11 M or possibly > 1 Gohm. The high Z meter would give some 10% too high, but not off by that much and especially not too low.

author: guenthert
author_rank: Frequent Contributor
timestamp: January 06, 2024, 08:48:39 am
content: If you don't have an electrometer with sufficient accuracy, you could use the 34401A against (series opposition) a well known second source of sufficient stability and voltage (potentiometer method). The 34401A (LO terminal) is good for potentials up to 500V above ground. Just be carefulThat allows you to use a low range with high impedance (and good resolution).But does the high voltage probe really expect a high impedance meter or does it specify a (terminating) input impedance?

author: Kleinstein
author_rank: Super Contributor
timestamp: January 06, 2024, 09:25:19 am
content: The linked probe specs show that the probe is made for 10 M meter impedance. So most modern meters should work, even with a high Z meter the result should only be some 10% high.
Fluke 5502A - Page 1
Forum section: electronics / general

author: Ugur
author_rank: Regular Contributor
timestamp: January 23, 2024, 07:13:39 am
content: Hello Guys,I need your experiences regarding the faulty Fluke 5502A.The device completes the diagnostic test without any problems. But there is a problem with the current outputs. There is no problem up to 330mA, but after 330mA level I get meaningless outputs. For example, at DC 500mA, I get a value like -100mA.In AC, it gives almost half of the set value.Maybe it can give you an idea, A7 these parts were defective and I replaced them with new ones.R59:100 ohmsQ10:MJE15029 (I installed MJE15031 instead)Q21:MPS6560R69-R71: 10 ohms. It was a little burnt on top, but it showed the correct value. I replaced it with a new one.U47:DG444K13: Relay
Z3801A LEDs on main board - Page 1
Forum section: electronics / general

author: 5065AGuru
author_rank: Frequent Contributor
timestamp: January 06, 2024, 01:48:06 am
content: Does anyone know what the row of 6 LEDs on the main board are for?Just found this so question answered!The six LEDs are:1. 'Boot code' if ON, Normal if Flashing, 'broken' if OFF2. EPROM failure3. CPU failure4. RAM failure5. UART failure6. QSPI, FPGA, interpolator, GPS, power failureIn normal operation all should be off except #1 which should be flashing. Above is from page 6-29 of the Symmetricom 55300A User's Guide.Cheers,Corby

author: johnk0gcj@gmail.com
author_rank: Contributor
timestamp: January 06, 2024, 03:16:06 am
content: Corby, I was going to suggest that you check k8cu.com but it looks likethat site is no longer available. The information that was there is stillavailable by searching for Z3801A, but you have probably found thatalready. That's just about everything available, technical info just isn'tanywhere to be found. There have been a few attempts to reverseengineer with a little success, but nothing really helpful. I have twoand have been lucky in that I've had no problems over the 20 yearsI've had them.John
Optical feedback to reduce noise in precision zeners - Page 1
Forum section: electronics / general

author: 5065AGuru
author_rank: Frequent Contributor
timestamp: January 01, 2024, 06:03:20 pm
content: Have enjoyed seeing the pictures showing the light emitted from a precision zener like the LTZ1000 or the ADL1000.Wondered if you sensed and scaled that optical signal and fed it back into an op amp on the zeners output if you could cancel out any noise?This would depend on the optical signal actually being correlated with the devices output noise.Does the LM399H family also show that optical signal? Cheaper to experiment with with first!Cheers,Corby

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: January 02, 2024, 12:42:50 am
content: I suspect it would be tough to detect the signal and not add a huge amount of noise, enough to swamp out the effect you're looking for. I used to use optical devices for position sensing and getting the noise down wasn't trivial. Phototransistors were terrible. Photodiodes were OK, but just barely good enough for my application.

author: ArdWar
author_rank: Frequent Contributor
timestamp: January 02, 2024, 12:07:37 pm
content: Dark current alone would be PITA to cancel out reliably. Most light detectors are also excellent IR detectors, and one thing about ovenized zeners is that they're hot.

author: magic
author_rank: Super Contributor
timestamp: January 02, 2024, 12:12:04 pm
content: Is it practical at all, even in theory, with noiseless light detector and so on?Say you have a DC+AC signal which is correlated with noise, what can you do with it?Subtract the DC offset and add the rest to the output?How would you do it, using a separate reference? What about its drift and noise?RC filter? Might as well put it on the normal output of the reference chip...In practice...Dark current of photodiodes increases with temperature - obvious source of drift.The light output of zeners is weak, so the signal you are looking for (if it even exist) may be swamped by noise.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 02, 2024, 05:53:21 pm
content: There can be an indirect link between the light emissions and the popcorn noise. However this is ideirect and hardly usable to reduce the noise: with a higher votlage there are some hot electron produced and these can excite states at the oxide interface. These higher energy states can than cause light emissions or if there are long lived ones at sensitive positions they can effect the electrical properties and produce random telegraph type noise. Howeve the amount of light shows that there is way more light than extra noise. So there is just a good chance to have a similar mechanism and parts that produce a lot of light may also be noisy. Still the light is likely not directly correlated with noise and thus no "correction" possible. Even if there is a small effect chances are one would add more noise than remove.
ZYT GPSDO (Trimble) incorrect frequency - Page 1
Forum section: electronics / general

author: jacekowski
author_rank: Contributor
timestamp: January 07, 2024, 11:48:06 am
content: I've got an odd one.I've got ZYT GPSOD with trimble guts that used to work fine but recently started to have 0.3Hz error.Powers up fine, locks and reports frequency as 9999999.7Hz while producing almost perfect 10MHz then after few hours reported frequency changes to 10MHz with mHz error. but actual frequency is 0.3Hz high53131A in the photo is running from different GPSDO and this ZYT GPSDO is the only odd one out so, unless 4 other clocks are producing same error, the fault is with this one.Any suggestions on what the issue might be?
DC-CAL Mini - DIY Multifunction calibrator - Page 1
Forum section: electronics / general

author: iMo
author_rank: Super Contributor
timestamp: November 12, 2019, 07:32:23 pm
content: FYI - Simple voltage/current/resistance calibrator, based on the AD5791 with LTZ1000 voltage reference.Made by Mickle, I think.http://bbs.1ppm.cn/topic/340/dc-cal-mini-diy-multifunction-calibrator

author: antintedo
author_rank: Contributor
timestamp: November 13, 2019, 04:18:37 am
content: Topic made by the project author on another forum:https://radiokot.ru/forum/viewtopic.php?f=10&t=162357This is very well documented, page 6 has a link to schematics and gerbers.

author: felixd
author_rank: Regular Contributor
timestamp: November 30, 2023, 09:49:24 pm
content: Thank You! Dzięki

author: Rax
author_rank: Super Contributor
timestamp: November 30, 2023, 10:04:46 pm
content: Quote from: iMo on November 12, 2019, 07:32:23 pmWas everyone else able to go to the site? Maybe it's mine or my ISP's security or some such thing, but I can't access the site.

author: Hawaka
author_rank: Regular Contributor
timestamp: November 30, 2023, 10:21:30 pm
content: The website works, but I had to disable my PiHole to access it.Looks like a very nice and well documented project, too bad I am not fluent in russian…

author: MegaVolt
author_rank: Frequent Contributor
timestamp: December 06, 2023, 11:13:23 am
content: Quote from: Hawaka on November 30, 2023, 10:21:30 pmThe author of the project is present on this forum. And I think he can answer questions in English.
Is there a way to screen capture the trend plot or histogram on Fluke PM6690?   - Page 1
Forum section: electronics / general

author: FredWDaniel
author_rank: Newbie
timestamp: December 03, 2023, 04:35:36 pm
content: I cannot find a way to capture the screen and make a jpg file to include in an article, without taking a photograph of the front panel. My firmware is v1.14s

author: alm
author_rank: Super Contributor
timestamp: December 03, 2023, 04:42:23 pm
content: Have you checked the programming manual for "screen dump" or "hard copy"? Theversion I found onlinestates that there's a :HCOPY:SDUMP:DATA? command that will return a screen dump in BMP format.

author: FredWDaniel
author_rank: Newbie
timestamp: December 04, 2023, 05:01:03 pm
content: Thank you, I could not find it.....