hybridfree/eevblog-posts huggingface dataset:
Warshawsky bridge 10K measurement article  - Page 1
Forum section: electronics / general

author: Overspeed
author_rank: Frequent Contributor
timestamp: November 08, 2024, 07:57:22 am
content: HelloI link an interesting article on the Warshawsky bridge for 10K measurementRegardsOS

author: BILLPOD
author_rank: Frequent Contributor
timestamp: November 08, 2024, 02:31:21 pm
content: Good Morning Overspeed, I had never heard of a Warshawsky bridge, so thank you for introducing it. Now I'm going to see what Uncle Google can tell me about it. I have always been intrigued by electrical bridges.

author: ivo
author_rank: Regular Contributor
timestamp: November 11, 2024, 08:22:11 am
content: Complementary detail is in the below PDF, found fromhere
Datron 1271 GPIB access to error listing - Page 1
Forum section: electronics / general

author: View[+]Finder
author_rank: Unknown
timestamp: November 10, 2024, 04:56:44 pm
content: With a Datron 1271 having "problems" (including a broken right-side display), here is a Python script to use PYVISA and GBIB to read the device dependent error list.Code:import pyvisaimport timevisa = pyvisa.ResourceManager()DT1271 = visa.open_resource('GPIB0::2::INSTR')DT1271.timeout =20000#DT1271.write('CNFTST?') #run confidence testinput() # to give time to run testerror = 9999while int(error) > 0:error = DT1271.query('DDQ?')print (str(error))time.sleep(0)print (DT1271.query('*IDN?'))DT1271.close()The CNFTST? command is in the Datron_UserManual_Issue1 on page 5-65 (BIG THANKS to xdevs for the source)This will probably work for the full test, etc. but not tested yet.
ADCMT 5350 Digital Electrometer any reviews ? - Page 1
Forum section: electronics / general

author: Overspeed
author_rank: Frequent Contributor
timestamp: November 09, 2024, 05:31:45 pm
content: HelloADCMT 5350 Digital Electrometer is a low cost ( following the website ) with 5 1/2 digit plusany reviews or advice ? as ADCMT was a part of Advantest up to 2003 so quality shall be greatRegardsOS

author: EC8010
author_rank: Frequent Contributor
timestamp: November 09, 2024, 06:12:40 pm
content: The key specification in the specification is the input leakage current of < 30fA. So whilst it might have 1fA resolution, it's only accurate down to 1pA. Which is good enough for most stuff. For comparison, a Keithley 6517 is typically 3fA input leakage current and a Keithley 6430 is 1fA.

author: aronake
author_rank: Frequent Contributor
timestamp: November 10, 2024, 03:08:09 pm
content: I have an ADCMT 8252 which I could see being quite similar to the 5350 but also have a 200V voltage source for resistance measurement. I have not tested it out to much in detail but it is doing a very good job where 3458a is struggling, like low current, high resistance and need for very low current load voltage measurement.I also have a ADMCT 5450 ultra high resistance meter. That is also very good, but lack the voltage functionality and seems to have a slight edge for low current measurement. It is on my todolist to compare these and my Keithley 2450 in low current measurements.
Stable 120V AC power supply? - Page 1
Forum section: electronics / general

author: pcee
author_rank: Regular Contributor
timestamp: November 09, 2024, 02:33:17 am
content: Is there such thing as an inexpensive ACstablepower supply? In the devices I'm testing, the +/- 0.5% variation in mains voltage is causing about a +/- 1.5% variation in measured output. I'd like to eliminate that variability.The closest thing I've found is theInstek APS-7050E, but (a) it's still over US$1600, and (b) I can't quite tell if it would actually be an improvement from its specs. (I'm not sure whether its line regulation spec of 0.1% of full scale is 0.1% of 120V or 0.1% of 500V, and whether that's just accuracy rather than stability.)Is there a different or a better solution? The DUTs are generally under 120W max, and usually quite a bit lower.Would a double conversion UPS tend to be more stable? These seem to be a bit more affordable, at $600 for theTripp Lite SU700XLCDor $750 for theEaton 9SX700, but I don't know if they're necessarily more stable either.I've even heard discussions of feeding an AWG sine wave into an audio amplifier to produce 120V, but I'm not sure what specs I'd need in such an amplifier or what kind of load it could support.I'm fine with something secondhand, so long as it produces a steady voltage and frequency even when mains fluctuates.

author: bastl_r
author_rank: Regular Contributor
timestamp: November 09, 2024, 06:54:56 am
content: In my reason you will need minimum a calibrator like an old HP745a or similar to reach the accuracy of 0.1%!Maybee additional with a amplifier.

author: Overspeed
author_rank: Frequent Contributor
timestamp: November 09, 2024, 08:13:46 am
content: HelloWhat current level do you need ?RegardsOS

author: andrewtaylor
author_rank: Contributor
timestamp: November 09, 2024, 12:59:01 pm
content: Quote from: pcee on November 09, 2024, 02:33:17 amI use a sine wave generator followed by a professional audio amplifier with PA output: Klein&Hummel TelewaTT 240 for this work.It has an internal 100V output transformer output for the 100V ELA lines.And support a little overdrive to 120V withour distorsion raising too high.It warks perfect for 50/60/400 hz tests.more details (use deepl.com if you need different language):https://www.radiomuseum.org/r/klein_telewatt_mono_endverstae_6.html

author: pcee
author_rank: Regular Contributor
timestamp: November 09, 2024, 02:28:10 pm
content: Quote from: Overspeed on November 09, 2024, 08:13:46 amUsually 1A or less.I can imagine going up to 2A for some devices, and I can't imagine ever going above 4A. So I think a 500VA power source would be more than adequate.I've seen a few Chroma 6404 and 6504 power sources on eBay that are in the $700-$800 range, would they be a good option?

author: mzzj
author_rank: Super Contributor
timestamp: November 09, 2024, 08:14:16 pm
content: Audio amplifier and toroid transformer. If your load has fixed power consumption you might be able to run it even open-loop. Otherwise you'd need to put the transformer inside some sort of feedback loop.
732c Comes Back from Keysight Tomorrow! - Page 1
Forum section: electronics / general

author: CalibrationGuy
author_rank: Unknown
timestamp: October 30, 2024, 07:54:20 pm
content: I've been working on our voltage standard bank for years. We recently acquired a 732b from a forum member here (thanks Steve). Our 732c was sent to Keysight for a Standards Lab Calibration. Their lab sent me a .pdf of the report today. The bank assigned value is only 0.121ppm away from their assigned value!I am astounded by this result. The Fluke units are pretty impressive. The bank is comprised of 3x732a, 3x732b, and the 732c for those who are curious.I just received 30 ADR1399s and will be able to characterize their drift precisely. We also have 2 ADR1001 eval boards and will test those for drift/performance.Some forum members are relatively close to our lab and I've invited them to "share the volt" with us when the unit is back and stabilized.TomG.

author: laichh
author_rank: Regular Contributor
timestamp: October 31, 2024, 12:03:11 am
content: Hi,Which Keysight lab did you sent to? and what is their reported uncertainty?Thanks.

author: CalibrationGuy
author_rank: Unknown
timestamp: October 31, 2024, 02:12:00 pm
content: I sent it to the Keysight Primary Standards Lab in Roseville, California. Uncertainty for my calibration at 10 VDC was 28nV.TomG.
ADI on how to achieve 7.5 digits accuracy - Page 1
Forum section: electronics / general

author: iMo
author_rank: Super Contributor
timestamp: October 23, 2024, 11:12:41 am
content: Part 1 and 2 from July 2024..https://www.analog.com/en/resources/technical-articles/achieve-7-pt-5-digits-accuracy-instrumentation-apps-part1.htmlhttps://www.analog.com/en/resources/technical-articles/achieve-7-pt-5-digits-accuracy-instrumentation-apps-part2.html

author: RoGeorge
author_rank: Super Contributor
timestamp: October 23, 2024, 06:16:49 pm
content: Nice exercise of selecting the parts for a 7.5 digits. It is not clear to me if the design was put in practice. The block diagram shows the generic picture of two ADI evaluation boards (all disconnected).What exactly was measured in part 2, the eval board?P.S. I'm halfway reading through the article linked in the bibliography, and enjoyed that a lot so far. Good bird-eye view and interesting insights, thank you.https://www.analog.com/en/resources/analog-dialogue/articles/can-you-really-get-ppm-accuracies-from-opamps.html(by Barry Harvey)

author: MasterT
author_rank: Frequent Contributor
timestamp: October 23, 2024, 07:02:10 pm
content: https://www.eevblog.com/forum/metrology/adi-shows-how-to-achieve-7-5-digit-accuracy-in-instrumentation-applications/

author: iMo
author_rank: Super Contributor
timestamp: October 24, 2024, 09:10:36 am
content: On the other hand repetitio est mater studiorum..
Designing bulletproof voltage standards - Page 1
Forum section: electronics / general

author: MiDi
author_rank: Frequent Contributor
timestamp: October 26, 2024, 03:17:38 pm
content: There is a lot of information around the design of precision voltage references (e.g. LTZ/ADR1000, LTFLU, 1N829), but it seems there is not much information to make it bulletproof.Scope:- battery powered, but connector for charging/offline operation included (external charger/PSU is out of scope)- typical 1..10V output (low/high voltage outputs are out of scope)- enclosure with connectors (cabling and external components/instruments are out of scope)- operation inside specified operating conditions for temperature, pressure, humidity (influence of those environmental conditions are out of scope)Naive bulletproof design goals:- Iout ±1mA DC & ACrms up to 1MHz- unlimited short circuit to ±1.5kV DC & ACrms up to 1MHz with recovery to specs <1min- ESD protection to highest classes of HBM/MM/CDM with recovery to specs <1min- EMI immunity in rough environments- immunity to capacitive loads with recovery to specs <1min after connection- no significant degradation of performance/spec regardless of the applied disturbance- DIY-able for hobbyistWhat is your approach, design, knowledge, best-practice, ideas, specifications, goals, documents, links, ...?

author: MiDi
author_rank: Frequent Contributor
timestamp: October 26, 2024, 03:19:48 pm
content: placeholder

author: Andreas
author_rank: Super Contributor
timestamp: October 26, 2024, 06:29:13 pm
content: Hello,first: I would only spec features that I can prove per measurement.(I guess that your EMI goals are out of your hobby budget)Some EMI improvements are shown here:https://www.eevblog.com/forum/metrology/emi-measurements-of-a-volt-nut/My worst case scenario is a unintentionally direct connection to a 1000V calibrator(which is current limited to some 10 mA and switches off within some ms)So a 11V TVS diode should handle the mistake.My references (LTZ1000 and AD587LW) are designed/proven to handle capacitors at the output up to 10 uF.with best regardsAndreas
Keithley 228A Rom dump - Page 1
Forum section: electronics / general

author: Jetecnet
author_rank: Contributor
timestamp: October 18, 2024, 06:08:29 pm
content: Anyone got a rom dump for the Keithley 228 or 228A? I have a unit shows +/-1 left display on boot, nothing else and no activity on cpu board apart from oscillator. I've replaced the cpu and ram, some logic, no progress. TIA JC

author: Hydron
author_rank: Super Contributor
timestamp: October 19, 2024, 09:13:45 am
content: I'll dig my 228A ROM dump out later. Was going to suggest KO4BB but it seems to be down again.

author: Hydron
author_rank: Super Contributor
timestamp: October 19, 2024, 10:27:22 am
content: See attached. If anybody else has something newer then please contribute!

author: Jetecnet
author_rank: Contributor
timestamp: October 19, 2024, 07:26:18 pm
content: Awesome! Thank you. I'll try it on Monday. JC
FLUKE 5100B calibration failure help - Page 1
Forum section: electronics / general

author: Louis_C
author_rank: Contributor
timestamp: October 16, 2024, 06:47:39 pm
content: I need some help adjusting a Fluke 5100B. I had to run a calibration on our unit yesterday to keep it up to date. Well, it failed on two points AC and DC high voltage. The spec for the DC at 1000v is LOWER LIMIT = -1000.0600 and UPPER LIMIT = -999.9400. Unit failed at -1000.1741. AC LOWER LIMIT = 699.601. AC UPPER LIMIT = 700.400. Unit failed at 698.211. Where do I adjust the unit to correct these voltages? Thank you in advance. Lou.
Zero Ohm connector plates ? an advantage compare to single point ? - Page 1
Forum section: electronics / general

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 15, 2024, 06:03:39 pm
content: HelloIn NIST 1458 Measurement Service for DC Standard Resistors , they use a triangle zero ohm rather than a single point connectionDoes that really provide an gain / improvement as that not complicated to machine from copper plate .RegardsOS

author: Wazza
author_rank: Contributor
timestamp: October 15, 2024, 07:40:56 pm
content: The 'advantage' when presenting zero ohms for a *4 wire* measurement is that the current flow from the stimulus/source terminals does not pass through the meter terminals in any configuration. This reduces possible measurement errors.Of course thermal emf errors could still be present, depending on the materials used to make the connector plate; but that's another rabbit hole to fall down....Waz

author: manganin
author_rank: Regular Contributor
timestamp: October 15, 2024, 09:34:48 pm
content: See section III in the SR1010 manual:https://www.ietlabs.com/pdf/Manuals/SR-1010_im.pdf

author: thermistor-guy
author_rank: Frequent Contributor
timestamp: October 16, 2024, 12:28:06 am
content: Quote from: Overspeed on October 15, 2024, 06:03:39 pmAlso known as a four-terminal junction. It can be circular. See fig. 12 in Riley 1967

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 17, 2024, 11:27:20 am
content: Quote from: Wazza on October 15, 2024, 07:40:56 pmHelloThanks for the linksThermal emf is a concern in design as that mostly impossible to avoid material mix , but try to be close is possible .Can be interesting to design a mechanical ''frame'' or old style circuit and make tests .RegardsOS
Thunder resistor precision China made ? any tests / reviews  - Page 1
Forum section: electronics / general

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 11, 2024, 09:45:49 am
content: HelloDoes someone have tested this brand of resistor ?http://www.thunder-precision-resistor.com/contactI have contacted them but I have still no answerRegardsOS

author: manganin
author_rank: Regular Contributor
timestamp: October 11, 2024, 11:31:39 am
content: Quote from: Overspeed on October 11, 2024, 09:45:49 amI guess you contacted her.(Sorry, couldn't resist.)

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 11, 2024, 11:49:08 am
content: HelloI have send 3 mails to sales@.....one for price list one for samples one to the sale dept in Canada and no answer yetAfter some search on Google this company exist since some years but there is no reviews / tests available on the net ( search done in english ) even if they propose interesting products ( depend to the sale price )Years ago I have tried to contact and purchase strain gage from BCM Sensor ( China ) with also no results , no samples , no price list .... and also no review on Internet .RegardsOS

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 15, 2024, 03:00:31 pm
content: HelloI have still any answers .RegardsOS

author: ch_scr
author_rank: Frequent Contributor
timestamp: October 15, 2024, 06:30:11 pm
content: Have you tried the Taiwanese "Token" resistors. They offer a lot of different types, HV and precision and custom networks etc.Most importantly, aseparate websitetouting:QuoteAlways wanted to try them
Datron 1271 GPIB access useful measurements - Page 1
Forum section: electronics / general

author: View[+]Finder
author_rank: Unknown
timestamp: November 10, 2024, 05:26:53 pm
content: For a variety of reasons, one might want to run the Datron 1271 from a remote location using GPIB. Maybe even over the internet . . ..PTVISA and GPIB make the task easy.Code:import pyvisaimport timevisa = pyvisa.ResourceManager()DT1271 = visa.open_resource('GPIB0::2::INSTR')DT1271.timeout = 20000DT1271.write('CLR PKPK')DT1271.write('RESL5')DT1271.write('DCV 10,RESL8,FILT_ON')#DT1271.write('OHMS E2,RESL8,2W,FILT_OFF')#DT1271.write('DCI E-3,RESL6,FILT_OFF')for i in range(1,11):DT1271.write('AVG AV64')r = (DT1271.query('RDG?'))[:15]print (str(i) + ',' + r)time.sleep(1)print (DT1271.query('*IDN?'))DT1271.close()The Datron manuals are essential (and available), however they are not searchable at the word level, only page-by-page.Taking measurements is easier than more modern meters as Datron sets 'range' based on the value of the input and the mode of the measurement. A 10VDC source will use very much the same code as 100 Ohms or 10mA.If there is a CAL script available, please identify source. External CAL is based on ZERO and a known full-scale reference for all settings (or even a single value CAL) and is easier than most.
3458a updates and drift checking - Page 1
Forum section: electronics / general

author: EE4all
author_rank: Regular Contributor
timestamp: October 09, 2024, 03:19:14 am
content: Here is my take on the 3458a updates.I have replaced:-Inguard supply electrolytic capacitors-Outguard supply electrolytic capacitors-Line filter-Rifa capacitors-Added sockets-Settings FRAM installed-Firmware updated-Added option 001 memory*The ZIF socket required moving 1 resistor and 1 capacitor to the underside of the board. I will be doing various projects with this one, so wanted the cal RAM easy to swap.*The cal SRAM has been backed up to PCTo Do:-New fan-Put labels on the firmware chips on top of the aluminum window covers-Source a fuse binding post that is missing-FRAM board for the cal socket, or just punt and put a new Dallas SRAM in for nowInstalled via a socket adapter-5000 different volt nuttery tests and fun times starting with drift tests-To be continued...Look at the date code on this old Dallas chip.It's still holding the data.

author: EE4all
author_rank: Regular Contributor
timestamp: October 12, 2024, 11:43:27 pm
content: Calibration SRAM replaced with FRAM and stacked socket adapter. I used 26 gauge magnet wire "inside" the adapter. The 28 pin FRAM socket has extra tall pins, so this gives the bit of space needed. I might have some boards made at some point but this works quite well.

author: IanJ
author_rank: Unknown
timestamp: October 13, 2024, 02:42:44 am
content: Quote from: EE4all on October 12, 2024, 11:43:27 pmYou can download the gerbers for my Cal board Pcb, see the video description of my video below.There's a couple of different versions depending on whether you want to use an SMD or TH FRAM IC.https://youtu.be/cAA1TCvwhuw?si=qWiON_Jy2flO4Ut3Go to @5:37 for the CalramEDIT:Just incase anyone asks, my 3458A was built in 2000 but I replaced the front panel with a new one from Keysight UK a few years ago. I still have the HP branded front panel.Ian

author: EE4all
author_rank: Regular Contributor
timestamp: October 13, 2024, 01:10:45 pm
content: Thanks, Ian! I had already downloaded your files for this actually, and I will get a few made. I was anxious to get the FRAM going in the meantime with supplies that I had on hand.Now I will leave it running, as I have no idea how long it was unpowered before I received it.I will begin logging some data soon, and have your WinGPIB set up as well.
BG7TBL GPSDO, measured the EFC voltage compared to freq. drift. - Page 1
Forum section: electronics / general

author: Wim13
author_rank: Frequent Contributor
timestamp: October 07, 2024, 04:44:42 pm
content: I wanted to know how the EFC voltage on Trimble OCXO in the BG7TBL GPSDO with display was behaving compared to the freq. drift.Because i noticed some frequentie jumps.It seems the Trimble OCXO type 73090 has a very sensitive EFC, a few Hz/VoltI used the HP3457A for the voltage measurment, resolution 1 uVolt, and Timelab for the freq drift.Measure time 1 hour.Fig 1, the voltage plotFig 2, the Timelab plotFig 3, just for info the Trimble OCXOFig 4, cold start EFC voltageFig 5, cold zoom EFC detail 1Fig 6, cold zoom EFC detail 2

author: Wim13
author_rank: Frequent Contributor
timestamp: October 09, 2024, 05:58:53 pm
content: I also measured the temp of the Trimble OCXO, as i can only measure on the case at the top of the OCXO case.So the sensor is touched to the metal on the top, and the metal box of the BG7TBL GPSDO is closed.i made a little connector on the back of the box, for the sensor, so there is no extra air flow.The final temp is 50,3 celsius, it takes two hours before it reaches it final.Next i tested what happened if i touch the outher GPSDO box ( so not the OcXO), for a few moments.The temp inside drops...see plot:
how to wire in current probe to coaxial cable - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: October 06, 2024, 11:33:50 pm
content: I have a AC signal in a coaxial cable within the bandwidth of my probe (up to 50MHz).What is the best possible way to wire in a probe to measure current?The best I came up with is to get a open pomona box (metal box with 2x bnc connectors) and clip the probe in there. It seems like its the least intrusive way.

author: jonpaul
author_rank: Super Contributor
timestamp: October 07, 2024, 07:32:45 am
content: If a BNC cable:Bare BNCs><wires><BNCPomona BNC ><EZhook adaptersOtherwise just cut the cable shield, and breakout a loop.j

author: coppercone2
author_rank: Super Contributor
timestamp: October 07, 2024, 09:00:52 pm
content: I thought the box might be more 'coaxial' then splitting the cables, because its a big chunk of aluminum.Another way might be to get a over sized braid with a slot in it that you put the probe into (like 1 inch braid), like a bulbous shape (puffer fish)I basically made the same thing as thishttps://i.sstatic.net/8I1fC.jpgfound onhttps://electronics.stackexchange.com/questions/505674/measuring-current-in-coax-cable-using-clamp-on-current-probea split one can measure return current however. Maybe you would use a braid rather then a wire for the shield wire

author: jonpaul
author_rank: Super Contributor
timestamp: October 08, 2024, 04:38:45 am
content: answer depends on the freq range of sig in the coax and of current being measuredj

author: coppercone2
author_rank: Super Contributor
timestamp: October 08, 2024, 04:40:08 am
content: the widest range is the best because the probe can do 50MHz but the cable 4GHz. Ideally you want a solution that goes into the GHz for people that have the expensive probes (not me)
setting up a shock test. - Page 1
Forum section: electronics / general

author: Simon
author_rank: Unknown
timestamp: October 07, 2024, 06:34:25 am
content: I need to carry out a test that involves something being dropped and an accelerometer measuring the impact and recording it.The test specification seems to have been created by an industry body rather than a specification body so feels a bit like they are not sure how to explain it.The system requires 1kHz of bandwidth, 10kS/s and the results needs to be low pass filtered with a -3dB filter @30Hz. There are some filter ripple requirements, at this point given that a -3dB filter is a simple RC filter I assume the ripple stuff is for digital filtering of the data.So I need an accelerometer with at least 1kHz of bandwidth and a low pass filter of 3dB. Given the brevity of the test I was considering using an oscilloscope to capture the waveform. I have a picoscope with 250MS/s so that is 10kS/s satisfied but I would put the signal through a physical RC filter so that sampling rate comes after the filter. But as the result is to be capped at 30Hz and the scope has 250MS/s it's the same thing?If my sensor has a higher than 1kHz bandwidth should I filter it to 1kHz ? or maybe 10kHz, the bit that I don't understand is that if this is all being filtered to 30Hz then why all the other numbers? Nothing faster than a 30Hz sine wave will pass that filter and unless a square wave were less than 3Hz it would not be accurately shown.

author: jonpaul
author_rank: Super Contributor
timestamp: October 07, 2024, 07:27:18 am
content: Dear Simon: Great question....shock impulses need wider BW than 1 kHz.We used to evaluate instrumant packing vs UPS/USPS handling and roughness...Box up the device, kick down a flight of concrete stairs 3 times.Open up packaging to see damages.....Jon

author: Simon
author_rank: Unknown
timestamp: October 07, 2024, 07:43:55 am
content: Well this is basically to evaluate the effects on a person. I am trying to understand if what is being asked for is doable or if there are just too many numbers in there.If the question is poorly framed then I need to come up with a way of answering it so that either they think it is what they want, or so that I can explain how it's the same thing.

author: Simon
author_rank: Unknown
timestamp: October 07, 2024, 07:52:06 am
content: If I put a 33.333ms pulse through a 30Hz filter (33.333ms = 1/30Hz) then and only then does the output get to 100% of the input. If I put a 1kHz sine wave through a 30Hz filter it comes out attenuated to 2.6% of the input.So if at worse case scenario of 1kHz @ 100% I only get 2.6% of the signal out of my filter the 10kHz sampling is for what?

author: Overspeed
author_rank: Frequent Contributor
timestamp: October 07, 2024, 01:26:54 pm
content: HelloAccelerometer shall be first selected by technology as piezo + charge amplifier or piezo ICP or strain gageA very common accelerometer use in shock test is the PCB piezotronic Model 350B21 able to reach 30 kHza shock is not really a simple pulsemounting affect also a lot accelerometer measurementRegardsOS
Agilent 16700B / 702B correlation with DSO9000 Infiniium scopes - Page 1
Forum section: electronics / general

author: F1GWR
author_rank: Regular Contributor
timestamp: October 01, 2024, 05:24:09 pm
content: Hi,Did anyone try to link a 16700B or 16702B LA to an Infiniium 9000 series DSO or MSO scope? Due to their different generation this has not been documented. But as the suggested Infiniium 54800 are the ancestor of the 9000, maybe there will still remain a bit of code in the latter to correlate both via ethernet +/- the E5850A correlation fixture?Best,Christian
Accubeat AR-40a information, manual, experience? - Page 1
Forum section: electronics / general

author: Cyclotron
author_rank: Unknown
timestamp: September 28, 2024, 10:07:01 pm
content: I just acquired an Accubeat AR-40A rubidium frequency standard. I've been looking for information about it, the lock output nature, the serial interface settings and command reference. Anything really. I'm hoping someone has some experience and information on the oscillator.Thanks

author: Cyclotron
author_rank: Unknown
timestamp: September 29, 2024, 03:16:33 pm
content: So I contacted Accubeat and they provided this manual. I was hoping for more information on the serial communications but I'm extraordinarily happy with the fact that they responded at all. To me, this is a sign of a great company. This oscillator is 2 generations old and no longer on the market for sale. I'm simply asking for information for study and my own research and use and they provided it on a weekend.I'll certainly be considering their products for my projects when I need new components.

author: Cyclotron
author_rank: Unknown
timestamp: September 29, 2024, 08:34:13 pm
content: Image of side 1 of board.

author: Cyclotron
author_rank: Unknown
timestamp: September 29, 2024, 08:35:49 pm
content: Oscillators mounted in this picture.

author: Cyclotron
author_rank: Unknown
timestamp: September 29, 2024, 08:37:19 pm
content: Other side of board.

author: Cyclotron
author_rank: Unknown
timestamp: September 29, 2024, 08:38:54 pm
content: As it stands, this unit does not appear to achieve lock. I have tested the output on the "BITs" pin for short to ground when locked and I do not see that happening. If someone is familiar with these and knows of a failure mode that is common, I'm very interested.
Fluke 87v calibration cost and where - Page 1
Forum section: electronics / general

author: crippledchicken
author_rank: Contributor
timestamp: September 21, 2024, 10:02:28 pm
content: I'm not sure if my meter might need calibration or not. Just checking on average cost and, where to have it done. Thanks!

author: mendip_discovery
author_rank: Super Contributor
timestamp: September 22, 2024, 06:50:33 am
content: Depends on where you live. I would suggest you look for a lab with 17025 accreditation.I doubt calibration will be that much. They are fairly generic.I have yet I to see a 87V that is outside specifications. Usually its leaky batteries or blown fuses I get.Also have you looked at getting your own references, maybe a 6.5 digit multimeter.... bwhahahaha

author: Arhigos
author_rank: Regular Contributor
timestamp: September 23, 2024, 09:03:15 am
content: Tektronix, Simco, Transcat is probably the biggest cal labs in USA. Z540 calibration should be around $80 or so
FE-5650A CPOM anyone with experience with this? - Page 1
Forum section: electronics / general

author: Cyclotron
author_rank: Unknown
timestamp: September 10, 2024, 09:44:35 pm
content: This FE-5650A CPOM does not show up in any documentation I've found. it is out of telecom gear and set to 15Mhz.https://www.prc68.com/I/FEIFS.shtmlI have attempted many ways to establish a serial or TTL connection with the DS80C323 chip, but nothing ever comes out of Ping 7.Does anyone know if there's a trick to talk to this unit or a means to adjust the frequency to 10 MHz?

author: testpoint1
author_rank: Frequent Contributor
timestamp: September 20, 2024, 01:58:31 pm
content: Quote from: Cyclotron on September 10, 2024, 09:44:35 pmI have many of this unit, to change the frequency, it is NOT by any serial (TTL or 232, depends the chip) command, it needs to set the jump resistor inside. any way, it is easy, but I never been post here since many seller want to sell it.

author: Cyclotron
author_rank: Unknown
timestamp: September 22, 2024, 11:16:48 am
content: Quote from: testpoint1 on September 20, 2024, 01:58:31 pmThank you. I have configured mine to 10 Mhz now. I'm exploring adding the 5 volt regulator so I only need to supply the unit a single 15v power.
INA826 as 10x instr. amplifier start deviating above 2V output - Page 1
Forum section: electronics / general

author: dusan
author_rank: Regular Contributor
timestamp: September 17, 2024, 02:26:56 pm
content: [ Specified attachment is not available ]I'm using INA826 (datasheethttps://www.ti.com/lit/ds/symlink/ina826.pdf) instrumentation amplifier with 5k1 gain resistor (gain = 1 + 49400/5100 = 10.68x and 105.1mV on vref pin to get away from the bottom rail):Up until 2V on the output everything is fine and output exactly matches calculated expected value. But above 2V it starts deviating. You can see it in this chart:Notes:- i tried 100k as a path to ground as datasheet suggest but it had no effect (the grounds of supplies are connected anyway so it doesn't matter)- individual inputs are 525mV 275mV, difference is 250mV- 100mV vref (actual value 105.1 remains constant during entire measurement), I separately measured it and it holds 100mV even at 47ohm load so it's not problemSo I can see 2 possible issues:- Is something wrong with my schematic or am I making some wrong assumption?For example 0.525*10.6 = 5.56 which is more than rail 4.5V, is this a problem?- my instrumentation amplifier is bad?Update:- I did another measurement where I removed R7 so that voltages on inputs * gain never exceeds rail and it clips even soonerina826_chart2.png(29.4 kB - downloaded 21 times.)

author: Alex Nikitin
author_rank: Super Contributor
timestamp: September 17, 2024, 02:41:47 pm
content: You would need a negative supply for the INA826 in this configuration. If you look carefully at the internal circuit of the chip, you would see that one of the first stage opamps outputs will hit the ground half-way. The first stage is trying to produce a differential output to the second stage and if there is not enough headroom you'll get what you see in your circuit.CheersAlex

author: dusan
author_rank: Regular Contributor
timestamp: September 17, 2024, 02:48:57 pm
content: Thanks.Symmetrical version works:
Shield cap BNC connector Pomona 2990 for information  - Page 1
Forum section: electronics / general

author: Overspeed
author_rank: Frequent Contributor
timestamp: August 29, 2024, 08:07:57 am
content: HelloThis japanese company propose an alternative to Pomona 2990https://www.sunjem.co.jp/archives/870/they have also interesting productsRegardsOS

author: Jeff eelcr
author_rank: Frequent Contributor
timestamp: September 15, 2024, 02:38:05 am
content: This looks like a Weco adaptor?Jeff

author: tooki
author_rank: Super Contributor
timestamp: September 15, 2024, 09:40:32 am
content: Quote from: Jeff eelcr on September 15, 2024, 02:38:05 amUhhhh… no?It clearly says it’s abinding postto BNC adapter to reduce capacitance, so it’s a banana plug with a big shield that covers the binding post.

author: Jeff eelcr
author_rank: Frequent Contributor
timestamp: September 16, 2024, 01:09:35 am
content: Tooki, I did not say it was one but that it looks like one other than size and BNC impedance, the design is simalar.I was unable to find any info on the Pomona 2990 for any reference.Overspeed, Was this just a notice or a question?Jeff

author: coppercone2
author_rank: Super Contributor
timestamp: September 17, 2024, 06:27:46 am
content: I see they have BPO connectors that are fresh. Its possible to equips some equipment with themIs there a triaxial BPO ?
Ovenaire OSC 49-38C repair possible? - Page 1
Forum section: electronics / general

author: e.sotillet
author_rank: Contributor
timestamp: September 12, 2024, 11:47:27 am
content: Hi folksI recently buy a EIP 545A frequency counter with a defective Ovenaire OSC-49-38C. The +28V power supply is present but there is no output. I tried to open it but is rather difficult.Is repair possible with this kind of oven crystal oscillators? ¿What is the most common fail of these devices?Best regards

author: edpalmer42
author_rank: Super Contributor
timestamp: September 12, 2024, 04:35:19 pm
content: Are you sure about your pinout? That looks very wrong to me.The connector on the oscillator is a standard 7-pin tube socket. The numbering starts at the gap and goes clockwise. In the photo, the pin you've labelled as 10 MHz is pin 1, +28V is pin 2, etc. The connector that attaches to the oscillator should have the same gap as the connector on the oscillator so that you can't connect it wrong.You're showing pin numbers that are out of order. That never happens for obvious reasons. Regardless of which way you count from, there's no way those pins can be 3, 4, and 5.Unfortunately, it looks like there's an error in the pinout shown on the schematic. There must be a ground pin and none is shown. Does the wiring on the connector agree with the drawing in the schematic?

author: e.sotillet
author_rank: Contributor
timestamp: September 16, 2024, 06:09:59 pm
content: HiThanks for the reply. Regarding to J6, is the pinout of the connector located in the main board of the EIP 545A frequency counter, is not the conetion of the crystal oscillator itself.I manage to open it and found that the output signal was disconected, so I soldered it and the device comes to live againg. The most dificult part was to open the oscillator, a little of solvent help me out.The output signal is senoidal with around 1Vpp. I took a couple of pictures of the internal modules, trying to not disassembly the hole device because the thermistor and one diode is glued to the metal thermal cage of the crystal.Best regards

author: edpalmer42
author_rank: Super Contributor
timestamp: September 16, 2024, 08:03:33 pm
content: Glad to hear you got it working. That connector confusion had me worried.These oscillators spend their lives running at a rather high temperature. It's not surprising to find that components have developed bad solder joints - particularly if the component is one that has some self-generated heat. Since you've got it open, I'd recommend that you spend some time going over the board with a high-powered magnifiying glass to check for other components with cracked or oxidized solder joints.When you get around to reassembling the unit, I wouldn't solder the can back together since it looks like your oscillator also has screws. Just clean up the cover and screw it back on.

author: testpoint1
author_rank: Frequent Contributor
timestamp: September 20, 2024, 01:53:04 pm
content: as usual, if the ocxo broekn is not caused by over heating, you can repair it, if overheating long time, the inside crystal already burnt.
Supercap evaluation board. - Page 1
Forum section: electronics / general

author: miro123
author_rank: Frequent Contributor
timestamp: September 04, 2024, 02:40:33 pm
content: I've just drawn the initial schematics of supercap evaluation board.My goal is to learn the behavior of different suparcaps.My planning is as follow.1. Define what I want to achieve.2. Present the schematics for review.My idea is to use available components as much as possible. In my case I already have ADS1256 +STM32H7 acquisition board . Acquired data is streamed with UDP port to industrial PCThe first step is to perform difference measurements. Goal is to get an idea about the noise around DUTs while environment is kept the same for all of them?Later on start playing temperature, humidity or mechanical. But one by one. I'll try to keep the multi variable bonanza for the last step.See attached draft version of schematics. Critique tips or suggestions are welcome.I still dont make up my mind about the mechanics - do I need to keep the test board separated and connected via cable to Acquisition board or do I need put them together in one test chamber - in my case will be Hamming day-cast AL case.My first test are with two type of low current high impedance supercaps. I have bad experience with few high current supercaps in the past. I consider to start with two Vishay/BC low current supercaps. Proposal for good brand and caop series are welcome. I'm new in this area.My expectations in this project are low. I know that Aluminum electrolytic capacitors and SuperCapacitors have a limited service life. Add to this that during the liftime the parameters are changed.And I shoud not expect some breaktrough wonder here. Learning something new is the main goal

author: iMo
author_rank: Super Contributor
timestamp: September 05, 2024, 07:29:13 am
content: The best way to test them is to stress them a bit, imho. Higher voltages/currents, bigger temperature/humidity/pressure differences, etc. Otherwise you will spend years with the test..

author: The Soulman
author_rank: Super Contributor
timestamp: September 08, 2024, 12:52:57 pm
content: I'd suggest to add the ability to measure leakage current of the different caps.The nicest way to do that is to measure the voltage drop across R3 thru R8.Or more simple is to create a direct output from your voltage reference and do a differential measurement between it and the various outputs.
For EZGPIB users: tools to compile your EZGPIB code unmodified. - Page 1
Forum section: electronics / general

author: SanderMTI
author_rank: Contributor
timestamp: September 03, 2024, 12:47:19 pm
content: Those of you who use EZGPIB already know how brilliantly useful it is, and that we owe the late Ulrich Bangert much gratitude for sharing it with the world.One of my EZGPIB projects has grown into a rather large application, so I wrote some tools to translate the EZGPIB_ xxx functions into standard Pascal in order to compile with FreePascal 3.2.2.Pro: GPIB comms using a Prologix GPIB-USB adapter are way faster with the compiled version.Con: I have only written support for RS232, VCP drivers up to COM30 and the Prologix so far.The attached zip file contains everything I needed for my project, you may need to expand functionality for yours.PS.After 24 downloads, I have not received a single question,comment, suggestion or even a thank you.Putting downloads on this forum was obviously not a good idea.Forum members who are interested in compiling EZGPIB code into a WIN32 .exe file can PM me.Sander

author: pelule
author_rank: Frequent Contributor
timestamp: October 18, 2025 06:36:34 pm
content: ITs sound a brilliant Idea. i have startet with in 2017 also but stopped to medical reason.Unfortunately Ulrich Bangert passed away due to cancer, and there is no one remaing to further support,All I could get an information - it is based on a pascal engine, but could not get any further infos.My main points to improvents, is the debug dupport.Especially in a windows environment.I have made many system-level programming but on MS-Dos, i really adicted to turbo pascal IDE and Turbo Debugger. its a easy and great handling of debugging code,set a breakpoint run from reset to break. noe single step until you found the problem.this was not possible at ez gpib, due to an error in program, the brealpoint is not highighted, thus you never sure. if it reached the break or not, so i get allways lost.Please accept thus many typing errors.it is still caused by my medical issues (I have had 3 times astroke)
Fluke 199C ScopeMeter Calibration Question - Page 1
Forum section: electronics / general

author: danielw22
author_rank: Newbie
timestamp: August 27, 2024, 07:46:20 pm
content: I have a question about the 199C Scopemeter. I did the full calibration on it according to the manual, but after the last step in the PDF there was another step in the actual unit (CL 0943). Has anyone come across this before? I can’t find any reference to this last step online, and not doing that stop properly is making it so I can’t change the calibration date (although my adjustment data did save).I’ve highlighted the part of the manual attached here, it does CL 0920 fine and then proceeds to a step named CL 0943 that requires action.Any advice would be greatly appreciated. I think it might be related to firmware but can’t find anything out there.I will take a picture tomorrow when I attempt the calibration procedure again.

author: smaultre
author_rank: Regular Contributor
timestamp: August 28, 2024, 05:14:34 am
content: Hello it needs to calibration data to be valid, after finish calculations.

author: danielw22
author_rank: Newbie
timestamp: August 28, 2024, 12:07:38 pm
content: Thanks for the reply. I know it needs all calibration steps to be valid to change the date, however there is an additional step prompt on the unit itself that is not described in the manual. CL 0943 comes up after the CL 0920 Calculate Gain steps. I can't find CL 0943 in the manual or anywhere else, hoping someone can let me know if they're aware of this.
Rigol vs Siglent scopes in cheapest HD/12-bit segment.... - Page 1
Forum section: electronics / general

author: Hella_Wini22
author_rank: Contributor
timestamp: September 07, 2024, 03:44:36 pm
content: I'm looking at Rigol DHO800&900 series against Siglent's SDS800X-HD & 1000X-HD - top models within the line ( 4 channels, may available bandwidth)1. AWG and logic probe asde, looking at pure scope functions is there any substantial advantage on Rigol's side ?Rigol has only 1.25Gs/s max sample rate vs Siglen't 2Gs/s. And this evaporates quickly with number of active channels - so it halves at 2 channels and quarters at 3 ch or more.Even though Rigol924 has declared 250MHz bandwidht, this obviously has to falls with 3 or more channels. SIglent's has only 200MHz bandwidth and it has more sample rate to begin with.Siglent also has 2x memory depth - 100Mpoints vs Rigol's 50 Mpoints - both models share them for all channels.So, is there some significant advantage on Rigol's side ?2. What's the fundamental difference between Siglent's SDS1000X HD and 800X HD series ? 1000X HD series is priced significantly higher and I can't figure exactly why... 🙄

author: J-R
author_rank: Super Contributor
timestamp: September 07, 2024, 08:13:41 pm
content: What does this have to do with Metrology?
Hitachi V-1565 scope in X-Y mode, X axis problem - Page 1
Forum section: electronics / general

author: NightMoth
author_rank: Contributor
timestamp: August 14, 2024, 03:42:23 pm
content: Hello allI'm trying to draw some geometric figures on my Hitachi V-1565 scope in X-Y mode,and I always get figures shrinked along X axis.For rhombus expected X = 2V, but real is 1.2VFor square expected X = 3.8V, but real is 1.1VY seems always OK.div for two channels are the same, other settings according to user manual.Am I wrong with my expectations for figures sizes? or it is problem with my scope?

author: BrokenYugo
author_rank: Super Contributor
timestamp: August 14, 2024, 04:20:15 pm
content: Photo angle makes it hard to tell but it looks like the inner knobs of the volts/div knobs are not in the same position, both should be clicked into the "Cal" position if you expect the graticule to read out correctly.

author: NightMoth
author_rank: Contributor
timestamp: August 16, 2024, 01:16:29 am
content: Quote from: BrokenYugo on August 14, 2024, 04:20:15 pmThank you for reply! I re-checked inner knobs, both in the "Cal" position... it looks like it is indeed bug in my scope, maybe because it is too old

author: GLouie
author_rank: Regular Contributor
timestamp: August 17, 2024, 03:43:25 pm
content: What happens if you choose channel 1 for Y axis and channel 2 for X axis?

author: NightMoth
author_rank: Contributor
timestamp: August 19, 2024, 12:58:46 am
content: Quote from: GLouie on August 17, 2024, 03:43:25 pmThank you for replyYour suggestion led me to find where is the cause of my problem.When I was changing Ch1 to Ch2 for X axis by switching "Trigger source" knob, I found that physicaly applying some force to the knob in clockwise direction AFTER it set into selected position, makes Image on the screen to be correct.If I stop ap[lying extra force, image on the screen become shrinked again.This works for Ch2 and for Ch1 position as well.As for me, now it looks like there is hardware problem in "Trigger source" knob.

author: GLouie
author_rank: Regular Contributor
timestamp: August 19, 2024, 03:47:27 pm
content: Yes, you seem to have dirty switches. The easiest thing to try is to simply exercise the switches by turning them through their positions many times.It is much harder to disassemble the scope and attempt to get a switch cleaner fluid into the switch. I have not done this on my V665, so do not know how difficult this is.