hybridfree/eevblog-posts huggingface dataset:
RTD/NTC self heating compensation. - Page 1
Forum section: electronics / general

author: miro123
author_rank: Frequent Contributor
timestamp: August 18, 2024, 10:20:10 am
content: Hello,I was struggling with this subject in the past. During the Measurement meeting 2024 Dr. Pyte briefly mention that he use sqrt(0.5) current to determine the self heating effect. Later on somebody from chat session ask similar question.1. Here are my findings on this subject- Simply switching the test current and waiting for a wile does not work optimal for the most application.- if you want long the changing conditions influence the result - most application measure non constant temperature. E.g after changing the current and wait I see 0.2K difference. Is this self heating error or measured temperature changed over time?- 0.707 ration was good to realize via hardware but not optimal to solve the problem. That said it gives some improvement - I can describe it as pickin up of low hanging fruit solution.2. My best solution so far.I use the following model The thermal probe is represented with thermal resistance and thermal mass.Both parameters are variable over time since everything depend on testing environment , type of materials, fluid and fluid speed. Even simple fluid like air changes over time - Rh% atmospheric pressure, or somebody decide to open window or doorI use the RC electrical equivalent of the probe - Thermal mass is capacitance. Thermal resistance R.I use two test current I1 and I2. I constantly switch them I1, I2 , I1, I2....The temperature change is exponential curve. and I determine the exp function coefficients.The algorithm has two tuning parameters are - 1. I1/I2 ratio 2. Test current switching time.Higher current ratio allow faster and more accurate determine of exp function coefficients, but add HW complexity and HW limitations e.g. extra components, complex circuit, limited SNRI1,I2 chopper time determine in general the BW of my measurements. Some feed forward component can be added to improve the BWMy question is are there any better solution on this subject? How do you determine the self heating effect in your application?Lessons learned - Building something that it works is easy, making work for specific application is difficult but duable, making general purpose measurement equipment seems impossible for me.BR,MIro

author: Andreas
author_rank: Super Contributor
timestamp: August 18, 2024, 09:18:27 pm
content: Hello,my strategies are:- reduce the measurement current as much as possible (dependant on ADC input impedance) (e.g. using 33K NTCs instead of 10K standard value).- further reduction can be done by switching off (e.g. per Port-Pin) during those times where the ADC does no readingSee also 5Vs (switched) in AD587LW cirquit:https://www.eevblog.com/forum/metrology/ad587lw-10v-precision-travel-standard/msg1449488/#msg1449488with best regardsAndreas
Looking for someone in the Phoenix area with either GPSDO or frequency reference - Page 1
Forum section: electronics / general

author: ZGoode
author_rank: Frequent Contributor
timestamp: August 29, 2024, 07:50:36 pm
content: I need to calibrate my 53131A and 33120A since I just upgraded the references in them, but do not have my own frequency reference yet. I am in the process of building my own GPSDO, but in the meantime I am looking for someone with either a frequency reference or GPSDO that would be willing to help me with calibration of these two pieces of equipment.
Please inquire about the error records of the Tektronix oscilloscope - Page 1
Forum section: electronics / general

author: button.ch
author_rank: Contributor
timestamp: August 15, 2024, 12:28:34 am
content: Greetings to everyone,Masters, may I ask a question? How to clear oscilloscope error records about TDS3000 series. Thank you all! Wishing you all the best!
Pinout needed:  Isotemp  OCXO 143-141  - Page 1
Forum section: electronics / general

author: CraigD73
author_rank: Contributor
timestamp: March 28, 2018, 09:33:43 pm
content: Hi, I am looking for a data sheet or the pinout for an Isotemp OCXO 143-141 10Mhz oscillator.A web search turned up mostly conflicting information, seems Isotemp wasn't all the diligent about keeping there pin assignment constant over the various models. I would hate to release the blue smoke trying to figure it out.Thanks,Craig

author: chuckb
author_rank: Frequent Contributor
timestamp: March 28, 2018, 11:09:22 pm
content: I did not have a data sheet but a little searching on _bay provided the attached picture. A data sheet from another seller indicated the top LH pin is the VCO input and the top RH pin is the reference voltage (4V, 4k max load) for the frequency adjustment pot, if needed.Some specs700ma initial current draw at 5VDCCMOS output levelsHope this helps.

author: chuckb
author_rank: Frequent Contributor
timestamp: March 28, 2018, 11:13:19 pm
content: And here's a hidden surprise.

author: Cerebus
author_rank: Super Contributor
timestamp: March 29, 2018, 02:03:50 am
content: I haven't been able to find a datasheet for the 143-141, evidently it's a custom order out of the 143 series. Here's the series datasheet. The 143 follows the 'A" pinout.

author: flash2b
author_rank: Regular Contributor
timestamp: August 15, 2024, 06:26:48 pm
content: Datasheet:OCXO-143-1000.pdf(111.65 kB - downloaded 359 times.)
NEED Calibrate (or compare with calibrated) 7,5d and up DMMs in LA, California - Page 1
Forum section: electronics / general

author: smaultre
author_rank: Regular Contributor
timestamp: August 07, 2024, 06:41:47 am
content: Hello my friends, i just started to collect my home-lab, and i need at least one calibrated DMM. I pick a Keithley 2010for my hobby everyday use.And i want to calibrate it (or compare it with fresh calibrated 8,5d DMM). Who have some time and equip to help with my task? Location is LA, CA.

author: ITArchitect
author_rank: Contributor
timestamp: August 07, 2024, 06:59:18 pm
content: You might be interested in this:https://www.eevblog.com/forum/metrology/usa-cal-club-round-3-1/msg5390003/#msg5390003I've been kicking tires thinking about it as well.

author: Rax
author_rank: Super Contributor
timestamp: August 08, 2024, 11:34:02 pm
content: Enlisting on the US Cal Club is highly recommended (the FX is an outstanding standard, and it being available this way is an amazing opportunity. DO NOT PASS ON IT).Chances are at this time you may not have to wait too long to get the US Cal Club kit either. I had it here twice this far and the level of agreement with my standards has been uncanny.I'd not hesitate to get on that list.
Power Meter/Sensor uncertainty budget.. - Page 1
Forum section: electronics / general

author: moosebiscuit
author_rank: Contributor
timestamp: August 08, 2024, 02:23:41 pm
content: Good morning everybody. I've hit a wall!I cannot for the life of me figure out how to quantify the uncertainty for power measurements utilizing an Agilent E4419B and 8482A Power sensor. I've found some comparable scope's of accreditation that give me a reference for what values I should be getting close to. I have attached the part I'm referencing to this post. With this equipment I don't really know where to start. I've been using a nice range-calculator/budget that's useful for more basic utilities for one standard but I can't seem to figure out how to apply it here. This is what I have so far.- Past calibration certificates for both the 8482A and the Meter, both accredited calibrations with associated MU's.- According to the power meter's specifications, the Zero Set accuracy is +- 50 nW.- Power output is 1.00 mW (0.0 dBm) factory set to +-0.4% traceable to NPL- Power reference accuracy for two years is +-0.5% with my lab environmentals- Resolution of the power meter is .0001- SWR is 1.06 Maximum- With use of 8482A sensor, Zero drift is < +-10nW and measurement noise <110 nWSupplemental Data--From the Power Meter certificates I have power measurements expressed in Watts.From the Power Sensor certificates I have Voltage Reflection Coefficient tests displayed like so:The PHASE column is the measured PHASE(Degree).The MEASURED column is the measured MAGNITUDE.The MAXIMUM column is the specification of MAGNITUDE.The UNCERT column (if it is present) is the uncertainty for MAGNITUDE.As well as calibration factor measurements for the various frequencies, the factor itself, Cal fac uncertainty displayed in %, Refl Coef magnitude and refl coef phase along with this note on the bottom:The CAL FACTOR UNCERTAINTY (if it is present)is stated as an ABSOLUTE uncertainty.The RELATIVE uncertainty can be derived fromthe ABSOLUTE uncertainty by the following equation:RELATIVE CAL FACTOR UNCERTAINTY =100% * (ABSOLUTE CAL FACTOR UNCERTAINTY)/(CAL FACTOR)My questions..1.) Which of this information will need to be applied to an uncertainty budget? How do I quantify everything in the end for use in my CMC?2.) For repeatability testing, since I am quantifying one number for a range (100 kHz to 4.2 GHz, the range of the sensor) how would I go about that exactly? Tips?3.) What am I missing?Thank you kindly.

author: ap
author_rank: Frequent Contributor
timestamp: August 09, 2024, 09:22:38 am
content: Keysight makes available power sensor calculators. You could use this as a starting point.Just search for 'keysight power sensor uncertainty calculator'
Can anyone ID this resistor logo? - Page 1
Forum section: electronics / general

author: appsman
author_rank: Contributor
timestamp: August 07, 2024, 09:26:45 pm
content: I have a quite a few of precision resistors with this logo (see picture). They are all green like this. Some are as tightly spec'd as 0.01%. The logo has me stumped. I think there might be a letter "A" in it. Do anyone know who this maker is/was?

author: laichh
author_rank: Regular Contributor
timestamp: August 08, 2024, 03:17:49 am
content: Could it be Isabellenhütte?https://www.isabellenhuette.de/en/

author: EC8010
author_rank: Frequent Contributor
timestamp: August 08, 2024, 07:52:28 am
content: Probably not a European manufacturer because they would have (correctly) used lower case "k" for kilo. Using upper case "K" for kilo tends to occur in America. With that case colour, it looks like it's trying to be passed off as being made by Mann Components (UK, but bought by Vishay). Mann Components made resistors with tolerances down to 0.002%.

author: appsman
author_rank: Contributor
timestamp: August 08, 2024, 07:24:16 pm
content: If helps, here's another larger part with the same logo.
Were is the voltnut pdf mentioned in Amphour #674 ? - Page 1
Forum section: electronics / general

author: joechina
author_rank: Newbie
timestamp: July 30, 2024, 10:40:54 am
content: Hello guys!Dave mentioned in the amp hour #674 a PDF about voltage standards.I have a hard time findig it. It isn't linked in the podcast shownotes.JoeEdit:https://theamphour.com/674-turtles-as-a-service/It starts at 42min 30sec

author: ch_scr
author_rank: Frequent Contributor
timestamp: July 30, 2024, 12:05:53 pm
content: This onehttps://www.eevblog.com/forum/metrology/bye-bye-eevblog-hello-morphine/
ESI 300 PVB meter/bridge detector - Page 1
Forum section: electronics / general

author: trobbins
author_rank: Frequent Contributor
timestamp: July 27, 2024, 12:43:50 pm
content: A friend's 300 PVB had a non-operational plug-in detector module, which he carefully decapitated to then inspect the internal sealed circuitry. I picked up the 300 PVB a few weeks ago to do some comparison testing of its standard 0.1 to 1M decade precision 0.005% resistors against my HP 34401A, as each reference resistor allows 4-point connection through front panel terminals. Strangely, the detector decided to work again on the day I visited, so perhaps the issue was a poor contact with the 14-pin interface connector, or a chopper relay contact recovered, or the circuitry thought it was better to continue working again than risk more invasive actions.Anyway, I decided to reverse engineer the detector module circuitry as I couldn't identify any schematic or detailed description on-line. The schematic may have some errors, and its layout may be a bit unconventional as I couldn't identify any existing circuit layout to align it to. The chopper relay part had no markings.I also couldn't identify any detailed design descriptions to elaborate on the circuits operation, apart from some early simplistic chopper discussion in transistor manuals and app notes, and 'The Contact Modulator' series by Airpax - so would appreciate any operational insight or similar circuitry references.Attached is schematic, photo of detector internals, and an example measurement scheme of the versatile instrument which was advertised in Electronics Design 1966 by 'For $750 it does the work of 9 devices'.Ciao, Tim

author: trobbins
author_rank: Frequent Contributor
timestamp: July 29, 2024, 01:54:19 am
content: I've been able to identify a closely related detector circuit schematic in ESI's 250DE maintenance manual, which aligns with the 300 PVB detector schematic - so nice to see.As an aside, the mid-1960's 300 PVB reference resistors appeared to be still all within their 0.005% tolerance, based on an un-cal HP 34401A, but supported by transfer measurements on a 10R and 10k reference resistors with a Fluke 8588A and similar test temperature, and accounting for connection offset with the 10R.
Air Data Test Set Calibration - Page 1
Forum section: electronics / general

author: Poroit
author_rank: Frequent Contributor
timestamp: July 26, 2024, 03:19:15 am
content: Has anyone had any experience with Calibrating Druck ADTS Model 405 Air Data Test Sets?

author: mzzj
author_rank: Super Contributor
timestamp: July 26, 2024, 08:08:29 am
content: IIRC there wasn't nothing that special other than having to deal with military/aerospace and needing primary standard level gas pressure balance/dead weight tester.

author: Poroit
author_rank: Frequent Contributor
timestamp: July 27, 2024, 06:25:29 am
content: Do you remember anything about Error and Message Codes?I have been repairing SMPS in a number of these and then checking Controller Stability, Vacuum Leak and Pressure Leak.I have one that is displaying Message 303 after power up."ZERO OFFSET TO LARGE"I was curious as to whether this problem would be resolved with a calibration of the ADTS.

author: mzzj
author_rank: Super Contributor
timestamp: July 27, 2024, 09:11:38 am
content: Quote from: Poroit on July 27, 2024, 06:25:29 amManual would suggest that way. But in this case calibration means adjustment. Unfortunately the available service manual doesn't go into details what the "main calibration" consists of.Units I'm familiar with have passed the calibration(verification) without adjustments.

author: binary01
author_rank: Contributor
timestamp: July 28, 2024, 12:21:48 am
content: We often calibrate (and adjust) ADTS405s.I don't have any currently in the lab with that error to confirm the repair path, but I certainly recall seeing it numerous times in the past. Performing a calibration adjustment to better align the Ps and Pt sensors is worthwhile, and should hopefully correct the error. If the root cause is sensor failure or instability, it may not be succesful or may return after a short time, but we generally find them to have quite reliable resonant sensors (a strong point for Druck).Regards, Liam

author: Poroit
author_rank: Frequent Contributor
timestamp: July 28, 2024, 06:34:40 am
content: Thank you all for your feedback.
HP E4437B - Page 1
Forum section: electronics / general

author: Louis_C
author_rank: Contributor
timestamp: July 26, 2024, 03:14:52 pm
content: Does anyone know how to add the commands to Fluke Met Track 8.3.2 procedures (and sub procedures) to get the HP E4437B to communicate properly on the IEEE? These commands would be similar to how you setup an accredited calibration instructions. The commands would translate the HP E4437B "@" commands to language the Fluke software can understand.
Potential Prema 6040S repairs. - Page 1
Forum section: electronics / general

author: maginnovision
author_rank: Super Contributor
timestamp: July 19, 2024, 06:09:23 pm
content: It's been a while but I managed to get a 6040S. Unfortunately it was shipped from Lithuania to California, USA in nothing but 2 layers of bubble wrap and a trash bag. It sustained quite a bit of damage. Cards bouncing around, cracked boards, damaged connectors and pins, case broken. I got a refund and it seems like seller doesn't want to pay to get it back. I've decided to do a cursory look to see if it's worth my time doing anything with it other than recycling.First issue, minor, is that it is incompatible with the US grid with it being exclusively 220V 50hz. Major issue is lack of schematics. The damage it sustained really isn't small and I don't know where some of these broken connections went. So if anybody has schematics or other technical data it'd be really helpful.The front panel is mostly intact which is the only reason I'm considering it. It doesn't have a gpib board but I could use it without(even if I need to make something to keep it from failing due to gpib) as a standard lab meter.

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: July 19, 2024, 07:01:25 pm
content: Hi maginnovision,Prema doesen't support the Meters anymore,but at least they provide the User-manuals:https://prema.com/index.php/de/service/messgeraetewartungGood luck

author: maginnovision
author_rank: Super Contributor
timestamp: July 19, 2024, 07:55:25 pm
content: Thanks, the website never loaded when I'd try to check. That seems to have what I need. Now to see if I have all the parts I need to move to 120V/60Hz and fix connectors.

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: July 19, 2024, 09:26:41 pm
content: Hi again,...and they got it in english too:https://prema.com/index.php/en/service-en/maintanance-of-measuring-instrumentsThe 6040S-manual contains schematics too. :-)Best regards

author: unseenninja
author_rank: Regular Contributor
timestamp: July 20, 2024, 12:58:02 am
content: That is so sad to see...

author: coromonadalix
author_rank: Super Contributor
timestamp: July 20, 2024, 01:43:37 am
content: yep so sad went thru hell

author: maginnovision
author_rank: Super Contributor
timestamp: July 22, 2024, 01:55:25 am
content: Quote from: coromonadalix on July 20, 2024, 01:43:37 amQuote from: unseenninja on July 20, 2024, 12:58:02 amI was so incredibly disappointed when I saw it in a bag and then I picked it up and heard rattling...I'll have to start with clearing all the shorts from smashed components. I've so far managed to straighten the pins on the cards but I don't have high hopes for the overall project.While I'd like to pretend my German is good I did indeed get the English manual Roehrenonkel, thanks again.

author: unseenninja
author_rank: Regular Contributor
timestamp: July 22, 2024, 09:18:36 am
content: Good luck with the repair, I fear you may need all the luck you can get!
Symmetricom 4370A help please - Firmware, SD Cards etc - Page 1
Forum section: electronics / general

author: stewby55
author_rank: Newbie
timestamp: July 31, 2024, 01:16:10 pm
content: We have some of these, I gather they are quite old, and we only have a user manual for them. Eng info may have long since disappeared.If anyone has engineering info that they could share please, I'd be very grateful.Presently one had failed, there's an SD card fitted which had 3 partitions on it, none of which had a recognisable file structure by the PC.Another SD card (from a working unit and with similarly obscure file structure) was fitted, the Display showed lines going up/down denoting the locking / sync progress until it eventually locked up.When fitting the original card, the display shows a flat line and no eventual freq lock up.We'd like to duplicate the card for this and subsequent units, but it's contents are unreadable.If theres any suggections / info about SW backup to SD or cloning cards, plus menus / engineer modes etc, I'd be very grateful, thanks

author: darkspr1te
author_rank: Frequent Contributor
timestamp: July 31, 2024, 03:52:14 pm
content: It's possible the device can be read by Linux, which is able to back up a sdcard regardless of the file systemyou dont even need to install linux, just download a linux iso file , then using rufus application you write the iso to a usb flash driver and boot the pc to that flash, then using the dd command you can create a backup.darkspr1te
Agilent/Keysight 4155/4156C Performance Verification - Page 1
Forum section: electronics / general

author: moosebiscuit
author_rank: Contributor
timestamp: June 28, 2024, 08:35:00 pm
content: Hello everybody. I'm not very familiar with these units and how they operate, I'm looking to test their functionality in our in-house lab. I'm looking at the last certificate from Keysight and it looks like they just used some standard resistors and a 3458A to perform some voltage/current gain/measurement/offset tests. I have these, but I just can't seem to find anywhere additional guidance on performing these tests. Any assistance would be greatly appreciated! Thanks!

author: moosebiscuit
author_rank: Contributor
timestamp: July 17, 2024, 08:47:21 pm
content: Bump!Is anybody familiar with what it takes to test these models?

author: chilternview
author_rank: Frequent Contributor
timestamp: July 18, 2024, 07:48:37 pm
content: I have both a 4155B and 4156C . There is an Agilent service manual available from Artek Media for the 4155/4156. The official way was to use a performance verification program 'PV4155' - I think it was a HP Basic program on a floppy - but that is not available from Keysight who also no longer offer calibration services for the 4155/6.If you can get hold of the PV4155 program by twisting your local Keysight reps arm, let us know! Sadly I don't hold out much hope though.Other than that, you can obviously manually set the 4155/6 to output voltages/currents from the SMUs and measure with a DVM like a 3458A, or measure voltages/currents from an external source. Without knowing the GPIB commands to set the ADC reference though, you can only verify the performance, not change it.

author: moosebiscuit
author_rank: Contributor
timestamp: July 20, 2024, 03:48:18 am
content: I will give that a shot, thank you so much for taking the time to respond to this! I'll definitely let you know if I get anywhere. Do you know what all is on that service manual before I put money down on it? I was tinkering with it but wasn't confident in my understanding at the time but maybe the manual will help. I'm 99% sure keysight still provides cal services for these, but I might be wrong I might be thinking of a different vendor. Anyways, thanks again!!

author: chilternview
author_rank: Frequent Contributor
timestamp: July 20, 2024, 05:24:58 am
content: Quote from: moosebiscuit on July 20, 2024, 03:48:18 amthe service manual has some info on performance verification procedures and a basic functionality description with block diagrams etc. The thing it's lacking is schematics. Still, it's worth having.
my new avometer - Page 1
Forum section: electronics / general

author: m3vuv
author_rank: Super Contributor
timestamp: January 20, 2022, 09:31:41 pm
content: Hi all,i have just got hold of an avometer 9sx panclimatic,it has a number on the case:6625-99-943-1524,its in an drab olive green case and has ranges upto 3000v,pretty pleased with it as its mint condition with all the probes etc, any idea what date it would be?,and an approx value?,thanks in advance.

author: bob91343
author_rank: Super Contributor
timestamp: January 21, 2022, 01:32:15 am
content: I don't know but my guess is around 1960.

author: EC8010
author_rank: Frequent Contributor
timestamp: July 19, 2024, 07:55:23 am
content: Going rate for AVOs at a recent amateur radio rally was £5. Down from £10 the year before.
Change the recorded sampling rate on the Fluke Connect app? - Page 1
Forum section: electronics / general

author: EEVBubba
author_rank: Newbie
timestamp: July 17, 2024, 10:14:22 pm
content: In a video I watched, the person demonstrated changing the recorded sampling rate in the Fluke Connect app with a little "down-arrow", but in the version I have, no such option seems to exist! (3000 FC)It seems to default to around 3-4 samples per second, which is far too high for what I need.Ideas?P.S. The 377 FC has a completely different functionality when you select the "Info" (!) button. It comes up with sampling rate and duration, but that seems to be referring to the internal memory of the meter, not the app! So weird...FOLLOW UP: I did some testing with my new 377FC and I've got to say the Fluke folks are clearly not communicating internally or externally in any way! Basically, the 377FC is perfectly capable ofindependentlyrecording data, which you can thenlaterdownload with the app! It's like the hardware team and software team didn't communicate in any way and the marketing folks decided to emphasize the Fluke Connect functionality and more or less ignore the stand-alone logging aspect.The manual pays lip-service to the internal recording feature and the Fluke Connect implementation is just weird since you can record the data to your phone with the typical red "record" button, but the "Device Info" screen relates to the internal memory of the 377FC!Anyhoo, you can have your metercompletely disconnectedfrom the Fluke app and simply press the "Inrush/Logging" button to start a session. The one weird caveat is that you must(?) previously set the logging rate on the app, if you want to change it from the default.Weird...
Is this picoAmmeter useless? - Page 1
Forum section: electronics / general

author: watchmaker
author_rank: Unknown
timestamp: July 17, 2024, 11:09:42 am
content: https://www.aliexpress.us/item/3256805868333845.html?Problem for me is the description is in Chinese.Thanks,Dewey

author: EC8010
author_rank: Frequent Contributor
timestamp: July 17, 2024, 11:38:23 am
content: Probably.I've now made quite a few different electrometers, some going down to <1fA. But to learn how to make successful electrometers, you need one working one to use as a reference. Once you've learned how to get leakage currents down, you can make better electrometers than your "reference" one. Why is this relevant? Because when you want to measure little currents you need confidence in your measuring instrument, and if you can't even read the description of the instrument, how can you possibly have confidence?

author: ivo
author_rank: Regular Contributor
timestamp: July 17, 2024, 05:12:16 pm
content: I'd guess the technicalresolutionmight go down to 10pA from the ADC bit depth, but likely any readings down at that absolute level would be junk.
Open Source Fluke Connect equivalents? (basic data is fine...) - Page 1
Forum section: electronics / general

author: EEVBubba
author_rank: Newbie
timestamp: July 16, 2024, 11:21:57 am
content: Just wondering if there are any open source Fluke Connect equivalents?TBH, even just a decoded data stream is fine, I can use Excel!Also, can someone explain the real limitations on Fluke Connect for a hobbyist (will a subscription ever be necessary?)

author: RoGeorge
author_rank: Super Contributor
timestamp: July 16, 2024, 11:46:16 am
content: Try this one (I don't have a Fluke, but I guess it's supported):https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/I remember some Fluke models were also supported by sigrok/pulseview:https://sigrok.org/wiki/Supported_hardware

author: EEVBubba
author_rank: Newbie
timestamp: July 16, 2024, 02:31:56 pm
content: Cool, but I'm not sure if any of those programs would recognize a Fluke Connect protocol (Bluetooth, probably BLE). These modern Fluke DMMs don't have RS232.You can probably "intercept" the data stream with a Bluetooth terminal app, but it's probably not in a useful form!When I get my 377FC, I'll noodle with it and see if the data stream is accessible.
HP 5065A Rubidium Standard Repair/Restauration - Page 1
Forum section: electronics / general

author: pquadrat
author_rank: Regular Contributor
timestamp: July 12, 2024, 05:12:54 pm
content: Hi Everyone,I got a HP 5065A Rubidium Vapor Frequency Standard yesterday, for free. Got it from a calicration lab, which calibrated my EDC MV116 voltage standard, and they wanted to throw this 5065A away.It was not used for some time, hat some dust on it, but no corrosion or mechanical damage.I will follow this threadhttps://www.eevblog.com/forum/metrology/inspecting-aligning-and-testing-an-hp-5065a-rubidium/, replace all 100uF capacitors, and do the checks.It is a late production unit, S/N2740A0xxxx, already with the 10811-60109 Crystal Oscillator.Best, I could not spot any previous repairs, all seems to be original. Corrosion by the 100uF caps is very limited.Some pitures attached:-Peter

author: KE5FX
author_rank: Super Contributor
timestamp: July 12, 2024, 11:50:03 pm
content: Nice save! It's a good idea to replace all of the dry tantalum axial electrolytics -- meaning any that are sealed with rubber rather than glass -- not just the 100 uF parts. Pay particular attention to the 20 uF parts on A11.Most or all of the wet (glass-sealed) axial caps will be OK, but they should still have their ESR checked.

author: edpalmer42
author_rank: Super Contributor
timestamp: July 13, 2024, 12:48:10 am
content: If the capacitors have caused any damage to the traces, inspect the board*very*carefully. On my 5065A one of the traces was so completely destroyed that I didn't realize that there had been a trace there in the first place!It also wouldn't hurt to check the main power supply capacitors. On mine, they rotted away completely a few years after I got the unit. Corby (5065guru) said that it was an unusual occurance, but it's easy to test.Corby knows more about these things than the designers so he'll be a huge source of info.If you haven't already done so, search the forum for all references to 5065A. There's lots of good info and documents right here.Ed

author: pquadrat
author_rank: Regular Contributor
timestamp: July 13, 2024, 08:24:58 am
content: Thanks for all these little details. Of cource I did read Corbys thread, and I will follow his procedure.The 20uF caps are already normal electrolytics, not tantaliums, but original, so HP changed this in later models.With the corrosion, I have a very late unit, so there were 10 years less time to corrode. Overall, nothing looks to bad.Now I am just cleaning everything inside very carefully, should look new inside then.Peter
EZGPIB "include" files? (plus a call for a general EZGPIB topic maybe?) - Page 1
Forum section: electronics / general

author: SanderMTI
author_rank: Contributor
timestamp: July 26, 2024, 08:51:27 pm
content: Dear members,This post may be in the wrong place, if so, someone may/will step in and move it?Those of you who use the late Ulrich Bangert's EZGPIB pascal script compiler already know how immensely useful it is,and also that it has some bugs and things that plain don't work.One of the things which don't work is the "standard" Pascal {$INCLUDE filename} to pull in source code from another file.Has anybody solved this ?I would like to use this mechanism as a way to set up particular meter(s), so that the main application (Datalogger) stays"meter neutral" and just drives outputs and gets data from the meters.Things like setting measurement modes, ranges, autozero, and integration time are too meter specific to be "hard coded" into themain program, which is intended to be "universal".I want to put the meter specific stuff into include files, in other words.I have been writing EZGPIB code for about a year now, so I have come across most of the other issues and have work-aroundsfor them, just ask.More generally, It would be a good thing is someone picked up the torch for EZGPIB now that it is just a relic on the internet.So let us begin here:How many people on this forum use EZGPIB?I know of 2, and a third who asked a question about the syntax for functions a long time ago.Regards,Sander

author: mendip_discovery
author_rank: Super Contributor
timestamp: July 28, 2024, 10:17:22 am
content: This happens to plenty of projects, the person maintaining it passes on and it starts to lag on updates.I would suggest uploading the files to github as that seems to be the working place for group coding projects. I see there are some people still working on it, the files being last updated in 2021.I personally would look at the more modern offerings, such ashttps://github.com/PhilippCo/meas_rpi
Unable To Calibrate 34465A 10VDC Range - Page 1
Forum section: electronics / general

author: EE54
author_rank: Regular Contributor
timestamp: December 25, 2023, 02:46:24 pm
content: Hi everyone, I recently had a friend of my repair a broken 34465A that I bought. He manage to repair it but then it also had a problem where all DC ranges would drift over a few minutes. Problem was traced to a bad ADC buffer amp (OPA827). Now the unit will hold cal and not drift.But another problem arise. For some reason, all DCV ranges will accept new values except for the 10 VDC range. Even when supplying 10 VDC and entering 10.000000VDC exactly, it will still show a 7mV error that just can not be calibrated away.Could it be the 10VDC range has drift so much that it's outside the adjustable range? Could the new replacement buffer IC plays a role?It also has a Cal count of 271, which seems like a lot.

author: laichh
author_rank: Regular Contributor
timestamp: December 26, 2023, 03:52:25 am
content: Hi EE54,Did you perform [ADC and Zero Calibration] as mentioned in the Service Guide page 556 prior to the DC voltage gain calibration adjustment?

author: EE54
author_rank: Regular Contributor
timestamp: December 26, 2023, 06:32:15 am
content: My friend told me he performed all the calibration steps, tho I'm not sure if he used a proper shorting block or just use his 5700A to do the zero cal.

author: ITArchitect
author_rank: Contributor
timestamp: March 11, 2024, 05:18:33 pm
content: Has this issue been resolved? After the zero cal, did you run the auto-cal to compensate for any temperature drift? Curious on what was found or if it's still an issue.

author: EE54
author_rank: Regular Contributor
timestamp: March 21, 2024, 10:48:26 am
content: Hi, this whole thing was put on hold for a bit as I am busy with other projects. I suspects that my friend diy calibration was not adequate, I doubt he used a proper 4-wire short for the zero cal.I’m planning on having it sent to a local cal lab for a proper cal to see if the problem persists. I’ll update in 1-2 weeks.

author: EE54
author_rank: Regular Contributor
timestamp: July 10, 2024, 02:43:39 am
content: Apologies for the extremely late response. I’ve been busy.Finally got around to sending the unit to a proper cal lab.Unit was off in the DCV,DCI, Ohm ranges.After adjustments, the unit is reading DCV correctly again. No strange 7mV offset in the 10VDC range.So it seems a in correct cal was responsible for the strange offset.
Metrology  - Gauging Level of Interest  - Page 1
Forum section: electronics / general

author: BarrowBoy
author_rank: Contributor
timestamp: July 09, 2024, 06:40:09 am
content: Hi Folks,New here, but not new to Metrology, but never been hands on. I mainly focus on DC and LFAC Electrical Power, related Electrical unit's of measurement including Temperature. Dabbled a bit in non-contact temperature. I was actually staggered by the number of posts relating to the subject. Glad we got our own section within the forum. I've got catch up reading to do....lolWas wondering what level of interest fellow forum members had in the subject (especially those based here in Sydney, Australia) but not limited too. I guess that power of a internet these days. Would you be interested in seeing a bit more Metrology content, I know I would.Cheers

author: jonpaul
author_rank: Super Contributor
timestamp: July 09, 2024, 07:08:41 am
content: see also other forums like old VoltNuts, TimeNuts, etc.Jon
Combined LDO/Voltage reference vs discrete - Page 1
Forum section: electronics / general

author: nimish
author_rank: Regular Contributor
timestamp: July 06, 2024, 10:08:29 pm
content: I'm making a breakout for a Hamamatsu micro-spectrometer c12880ma which needs 5V and a buffer + SE->Diff conversion. I'm using OPA2392 for this, which has an Iq of < 3ma.Is there anything good or bad about using, say, an ADR3650 w/ its 70ma sourcing capability vs an LDO + a more general voltage reference?In total, the current draw @ 5V is something like 40ma max including the amps, sensor and a 1MSPS ADC.
E1392:IEEE no listeners - Page 1
Forum section: electronics / general

author: Louis_C
author_rank: Contributor
timestamp: June 28, 2024, 08:08:00 pm
content: Please see attached photo. Here in my company lab, we have a Fluke 5500A and an Agilent 3458A. We are running Fluke Met/Cal Met/Track 8.3.2 on GPIB. When I connect the units together and attach the NI GPIB-USB-HS adapter and try and open Runtime, I get the error you see in the photo. I have NO idea how to solve this issue. Does anyone have an idea as to why this is happening and how to fix it? Thanks!

author: rcjoy
author_rank: Regular Contributor
timestamp: July 03, 2024, 07:58:25 pm
content: Maybe your SRQ line is stuck. Try another GPIB cable.

author: Louis_C
author_rank: Contributor
timestamp: July 04, 2024, 01:20:17 am
content: SRQ has nothing to do with this. Other cables are no help.

author: guenthert
author_rank: Frequent Contributor
timestamp: July 04, 2024, 07:54:29 am
content: Quote from: Louis_C on July 04, 2024, 01:20:17 amYou seem to be very sure of that, so I presume you have done some tests already. It might help us helping you, if you share those and the results. What does work and what doesn't?Given the error message, I''d rather suspect a software error (MetCal not communicating properly with NI's VISA library). Does other GPIB/VISA software communicate successfully with the calibrator and DMM or other instruments on that bus?What does Fluke's support say?

author: mendip_discovery
author_rank: Super Contributor
timestamp: July 04, 2024, 06:38:38 pm
content: Is this a new feature that has developed on a machine that has worked ok in the past or are we talking about a new machine and the first time setting it up?

author: Louis_C
author_rank: Contributor
timestamp: July 06, 2024, 01:34:01 am
content: This is the problem...It's totally random. I upgraded the NIMax software to the latest version(s) Q3 and Q4. Different modules have either Q3 or Q4. Anyway, it just happens. Now, as I stated in my initial post, we are running Fluke Met/Cal Met/Track 8.3.2. OLD as dirt and running on Windows 10 Lenovo Mini's with 8gb ram. I'm starting to think it may be the hardware. The GPIB adapters are from NI so, no chicom junk here.
A vintage 1 Ohm resistance standard - Page 1
Forum section: electronics / general

author: Alex Nikitin
author_rank: Super Contributor
timestamp: June 26, 2024, 01:48:57 am
content: Just couldn't resist buying it. However it measures much better than I've expected for £20 !(The HP3245A used as a 100mA current source and Hioki DM7275 as a voltmeter for the resistance measurement, and the total measurement error could be up to 50ppm).CheersAlex
Symmetricom S200 with GPS interposer fixes Furuno GT-8031 week rollover issue  - Page 1
Forum section: electronics / general

author: tverbeure
author_rank: Regular Contributor
timestamp: June 01, 2024, 06:55:17 am
content: My flea market Symmetricom S200 came with a Furuno GT-8031 GPS module that suffered from the 1024 week rollover. Because of it from some reason, the S200 refuses to lock to the GPS 1PPS signal, even though there's really no reason why it shouldn't. (The date will be wrong, but who cares?)The solution is to send a "@@Gb" command to the GT-8031 module that gives a hint about the current date.There are at least two ways of doing that: Alex Forencich was able to patch the HCS12 microcontroller on his S350 to send this command at boot up. He posted about his solution yesterday:https://febo.com/pipermail/time-nuts_lists.febo.com/2024-May/109101.html.I went the other way and created an interposer PCB with an RP2024-zero that can intercept UART messages to and from the module and modify those messages or insert new ones. I finally got that to work today.The interposer uses an RP2024-zero to intercept, insert, and retransmit messages from and to the GPS module. It has a few connector and resistors, and when not powered by a USB cable, it's powered by a +5V pin on the S200 motherboard.The Furuno GT-8031 plugs in on top of it. I still need to buy the right spacers to make it solid...

author: testpoint1
author_rank: Frequent Contributor
timestamp: June 27, 2024, 02:06:28 am
content: the receiving sensitivity of GT-8031 is quite poor, you may consider change it to GT-8736:https://www.eevblog.com/forum/buysellwanted/the-end-solution-for-motorola-m12-gps-furuno-gt-8736d-129-usd/
Just getting into logging. - Page 1
Forum section: electronics / general

author: mendip_discovery
author_rank: Super Contributor
timestamp: June 22, 2024, 10:13:17 am
content: So the other week I realised the prices of the 34401A have dropped a little since I last looked and ended up buying one from@M0HZHfor not a scary price. It's not calibrated but going by the FW being fairly new and the cal count being over 150 I suspect its been well used. When I get a chance I will take it to work and see how it compares to the 3458A and 34401A I have there.I have since then connected a GPIB adapter and had a play with logging data from@essele10V refs I bought off him a few years ago when I also bought the work 3458A. They have been permanently on so they have been constantly aging.I am using@e61_philproject,https://github.com/PhilippCo/meas_rpito do the logging.Using initially the logging script to get it working I got this graph,This was while the 34401A was still warming up so not the most stable data in the world.I have since had a play with the code as I was getting random moments where for a few seconds the readings would wildly go from the general trend.Since then I have tried to get a good setup, with 20 readings every 2.5 intervals to cover for the 6.5 Digit Slow aka NLPC100. Calculating a mean of the readings and rounding to the 7.5 digits that you get from just using GPIB. I am also recording the Standard Deviation of those 20 readings. I am working on getting the script to use Suncal to calculate the uncertainty for those 20 measurements and give me some error bars. I have another unit logging the temp in the room but I think adding another BME280 to the Pi would be the better way to also log the environment.Standard Dev,As you can see there is some occasional random noise, I will look into improving this later. The wires are PVC and exposed to sunlight and other random projects nearby.10 V Measurement,I am quite pleased with these measurements as I think@essele(https://www.eevblog.com/forum/buysellwanted/fs-(uk)-home-made-ltz1000-10v-references-(aged)/msg4650874/#msg4650874) had this down as 10.000068 VStill to come is to measure the other 10 Ref I have, make a 10 kOhm ref and if possible start logging all 3. This for now is just an excuse to play with GPIB but logging data is also fun.
SOLVED: Fluke 5520a Error - ERROR 399: Fault during DIZ330U - Page 1
Forum section: electronics / general

author: CalibrationGuy
author_rank: Unknown
timestamp: June 20, 2024, 04:29:42 pm
content: I was verifying functionality of a newly acquired 3458a from eBay without any issues yesterday. Meter tested fine. Today, I put the shorting jumper back on and tried to do the 7 day calibrator zeroing routine. Got the following error: "ERROR 399: Fault during DIZ330U". Diagnostic routine stops at same error. Unit was working before 3458a check and removal of shorting jumper between AUX LO AND 20A binding posts. Voltage, current, resistance, and frequency outputs work normally.Any ideas, thoughts?TomG.

author: CalibrationGuy
author_rank: Unknown
timestamp: June 21, 2024, 03:44:52 pm
content: So I can answer my own question in case someone comes across this issue. This calibrator was working perfectly until I removed the copper jumper for the zeroing operation when I was testing the 3458a. I tried several different gauges of copper wire, stranded, single conductor, etc. After some head scratching, I decided to clean the tellurium copper binding posts again, this time really scrubbing the daylights out of them. After replacing the original (also cleaned) copper jumper, the test ran without issue.Moral of the story, check everything at least twice, and when it comes to copper binding posts, they can never be too clean. Hope this helps someone.TomG.
Interfacing the HP3490A with an AR488 - Page 1
Forum section: electronics / general

author: Joel_S
author_rank: Contributor
timestamp: June 20, 2024, 09:12:56 am
content: Hello,I am trying to control an HP3490A DVM from a PC via GPIB with an Arduino-based AR488, using PuTTY as the user interface.So far, two things already work :- When the 3490A is in "talk only" mode, measurement data is received and displayed as expected- When in "addressed" mode, I am able to control the functions of the 3490A (select functions, switch ranges etc ...) as explained in table 3-7, page 3-10 of the 3490A manual.However, when in "addressed" mode, I cannot receive measurement results over the HP-IB. It seems that the 3490A requires the ATN line to be activated, but the AR488 manual doesn't provide any information on how to do that.Any help would be appreciated ... the 3490A is a very nice beast !Thanks,Joel Setton

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: June 20, 2024, 10:15:29 am
content: Hi,why the double-post?https://www.eevblog.com/forum/testgear/interfacing-the-hp3490a-with-ar488/
90° 3006 trimmer adapter / direction changer - Page 1
Forum section: electronics / general

author: gmac34
author_rank: Regular Contributor
timestamp: June 07, 2024, 09:43:01 am
content: Hi, I'm reposting this here as maybe there is more chance the volt nut gang has come across this thing in some precision equipment.I have been working on an old lab scale form Sartorius, 1979 vintage. inside I have found some odd (to me) plastic contraptions that are used to make a couple of trimmer adjustable from the top.They snap on regular 3006p trimmers and allow them to be adjusted when the scale is assembled.Being old brittle plastic they didn't take to well being adjusted and are broken.For now I have solved replacing the trimmer in question with a bodged in 10 turn pot that will then face the hole in the right direction, but it is not ideal.are this thing still made anywhere? I cannot even find the right therm to search them.

author: tooki
author_rank: Super Contributor
timestamp: June 07, 2024, 10:14:25 am
content: It’s a long shot, but have you tried contacting the manufacturer? Contelec no longer makes trimmers, but the company still exists:https://www.contelec.ch/(If they sold their trimmer business to someone else, I’ve been unable to identify who bought it.)

author: mendip_discovery
author_rank: Super Contributor
timestamp: June 09, 2024, 09:29:24 am
content: That looks like a project for 3D printing, SLA or sumsuch to make the gears.
Fluke 5500A testing - Page 1
Forum section: electronics / general

author: Louis_C
author_rank: Contributor
timestamp: June 05, 2024, 11:14:52 pm
content: Hello all. I need to know how force a Fluke 5500A running on Fluke Mettrack 8.3 to go SRQ high and stop responding in the runtime procedure. This is just for testing only. Any info would be greatly appreciated.