hybridfree/eevblog-posts huggingface dataset:
Using a logic pulser - Page 1
Forum section: electronics / testgear

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 02, 2020, 12:27:31 am
content: For troubleshooting 1980s home computers. I have a logic probe and I prefer that to a scope or logic analzyer for vintage computers. The systems are so simple that all you really want to know is if there's a kind of signal or a stuck logic level.However I never used a pulser. I understand it uses a "strong" transistor to force a very short pulse at some higher current level like 100mA to override whatever is driving the line.But the pulse is so short how can I see anything on the probe? Now I see that pulsers go with the probe from the same company with a sync signal of some kind? The probe is synced to the pulser?Not clear.Worse are the eBay listings claiming to sell logic pulsers when they are simply selling logic probes with the word "pulse" on them. This isn't a pulser.And why are these things still so expensive?

author: TK
author_rank: Super Contributor
timestamp: February 02, 2020, 01:46:36 am
content: The HP pulser I tested sends a train of pulses, not a single oneEDIT: Actually it works like oPossum said... single pulse or train of pulses

author: oPossum
author_rank: Super Contributor
timestamp: February 02, 2020, 01:58:15 am
content: Logic probes often have a memory feature that will catch brief pulses. The indicator LED for this may be labeled 'pulse'.The HP 546A pulser I have can do a single pulse when the button is pressed or continuous repeating pulses when the button is held or locked.

author: Shock
author_rank: Super Contributor
timestamp: February 02, 2020, 04:09:29 am
content: Just to clarify, they come as separate tools or as combined logic probe and pulser. You still need two tools though if you want to transmit a pulse and use a probe elsewhere to detect it. At least without using another type of tool such as a logic analyzer or scope etc. It should state clearly if they are both tools in one and you would expect to see a pulse button on a tool that can pulse.On some probes they have pulse or mem mode switch (which may be confusing), mem works like an auto hold on a multimeter and that is how you can detect single pulses if it's too fast to notice. Either that or as mentioned leave the probe in pulse mode and send a burst of pulses from your logic pulser.They are fairly inexpensive unless you want the set of HP tools.

author: Shock
author_rank: Super Contributor
timestamp: February 02, 2020, 04:53:04 am
content: Some references of the HP logic tools which include a few troubleshooting tips.HP journalhttps://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1976-12.pdfOn page 13 it suggests what tool to use on what type of problem.Manualshttp://kripton2035.free.fr/Resources/HP%20545A%20Logic%20Probe%20Manual.pdfhttp://kripton2035.free.fr/Resources/HP%20546A%20Logic%20Pulser%20Manual.pdfhttp://kripton2035.free.fr/Resources/HP%20547A%20Current%20Tracer%20Manual.pdfDemonstration of themhttps://www.youtube.com/playlist?list=PL7K-x1E-x5j_XhmMCJg99_BhLusGDCUgT
Rigol TX1000 - Page 1
Forum section: electronics / testgear

author: NY2KW
author_rank: Regular Contributor
timestamp: January 29, 2020, 04:32:36 pm
content: Is the Rigol TX1000 RF test fixture (up to 1 GHz) a good value? I sold my DSA815 and replaced with a Siglent SVA1032X and soon after found a heavy discounted new TX1000 that can be controlled independent of a Rigol DSA using Rigols PC software. Anything close to its functionality as an educational tool?Jerry
Siglent SHS806 - Page 1
Forum section: electronics / testgear

author: aaronfreakz
author_rank: Newbie
timestamp: January 23, 2020, 06:39:18 am
content: I recently purchased a Siglent SHS806 oscilliscope.I m trying to record the captured waveform and extracting data via usb.However, the data value extracted via USB is does not tally with what was shown on the oscilloscope.I m reading a data from the power supply, measuring 0v-15v.The oscilloscope is reading 0v -15v correctly.I plotted the graph via the CSV fileBut the data recorded to the usb is not in Voltage, 0v-15v (see attached picture Y-Axis), but in some random values (i assuming is in either bits/byte, but unable to determine the conversion).I did see other user getting the data that corresponding to the oscilloscope reading (e.g showing 0v-15v on the data), but it did not post a way/guide to setup the reading on the axis.My oscilloscope firmware is 5.09.01.05Is there some settings that i need to adjust, so that whatever the oscilloscope detected corresponds to the data recorded values, especially on the Y-axis value, as I have been struggling for a few days already.?

author: elektrolitr
author_rank: Contributor
timestamp: January 28, 2020, 09:34:19 am
content: Look at the file headerCH1Time/Point:1msVolt Coef.:200000uvZero Pos:128The conversion looks simple from that-V= (value - Zero Pos)* Volt CoeffUsing the formula, I calculated that value 129 corresponds to 0.2V, 128= 0V and 203=15VLooks plausible to me

author: aaronfreakz
author_rank: Newbie
timestamp: January 29, 2020, 02:15:43 am
content: Quote from: elektrolitr on January 28, 2020, 09:34:19 amThe axis data look more valid right now.Also, are we able to set in the oscilloscope so that it directly shows the value instead of having this data and manually calculate to the final data?Thank you

author: elektrolitr
author_rank: Contributor
timestamp: January 29, 2020, 05:40:44 am
content: Probably no. I don't have the 806, so I just looked through the manual, I don't see any options.Of course, manuals usually are bullshit and only give some clues at best.But it's not that difficult to recalculate, if you already have the data in EXCEL. You only have to write one simple formula and paste it all the way.
MDP-XP Powersuppy malfunction - Page 1
Forum section: electronics / testgear

author: sajjad
author_rank: Newbie
timestamp: January 28, 2020, 10:41:36 am
content: I have recently purchased an MDP-XP Powersuppy, but after few days of use I was powering 60 Watt Car headlight, suddenly power supply restart and start malfunctioning, It doesn't matter what output I set there is 31 volt on output without any current protection and power output function as not working no matter I put in on or off it not stoping the output.
Need acquisition board / pictures of TDS6804B. Who can help? - Page 1
Forum section: electronics / testgear

author: flyte
author_rank: Regular Contributor
timestamp: May 17, 2019, 11:58:14 am
content: Hi all,I'm looking for detailed pictures of a TDS6804B or TDS6604B acquisition board, or a spare board with defects.I have a unit of which someone stripped components, and I would like to repair it.Who can help?Willing to pay a fee for it.Thanks in advance and looking forward to replies!- flyte

author: flyte
author_rank: Regular Contributor
timestamp: January 24, 2020, 10:56:41 pm
content: Just to mention, in case: topic is still actual and I'm still looking for pictures of a TDS6804B acquisition board or some board with defects to buy

author: LazyJack
author_rank: Frequent Contributor
timestamp: January 26, 2020, 11:16:10 am
content: I suggest you contact the TekScopeshttps://groups.io/g/TekScopesgroup.

author: flyte
author_rank: Regular Contributor
timestamp: January 26, 2020, 09:58:14 pm
content: Quote from: LazyJack on January 26, 2020, 11:16:10 amThanks for the suggestion, but if I'm not mistaken this group is for older Tektronix scopes. The TDS6804B is no longer being made, but it's not yet in the classic range I would say. It's a Windows based realtime scope with 8GHz BW and 20GS/s.

author: LazyJack
author_rank: Frequent Contributor
timestamp: January 27, 2020, 02:37:41 pm
content: Well, yeah, originally it was about older scopes, but all kinds of Tek gear is routinely discussed, like the TDS series. The folks there are extremely helpful and I'm pretty sure more then one of them has this scope.
Hantek HT3325?????? - Page 1
Forum section: electronics / testgear

author: Simon_RL
author_rank: Regular Contributor
timestamp: January 26, 2020, 10:50:10 am
content: I have been looking at the Hantek HT3325 on their website.I am guessing this product hasn't been released to market yet as I cannot find it for sale or any reviews. Just wondering if anyone confirm if this is a new product not yet released and if anyone knows the release date?TIA
Female connector for 2mm round Fluke/Agilent etc  probe ? - Page 1
Forum section: electronics / testgear

author: Odd
author_rank: Regular Contributor
timestamp: January 28, 2020, 10:29:02 pm
content: Fluke, Agilent and other's standard probes have a 2mmØ round probe pin.With Saleae logic analyzer, and other, similar products, I got nice small/SMD clips with single pin dupont type connectors.I would like to make myself adapters from the 2mm round pin, to a male/female dupont pin (simply solder the dupont male/female onto the 2mm round female, and shrinkwrap)- Are there any connector pins that are "compatible" with 2mm probes ? - preferably some that can take their full length (1.5cm or so)

author: tooki
author_rank: Super Contributor
timestamp: January 29, 2020, 06:55:00 am
content: Yes. They’re made by test connector companies like Hirschmann, Pomona, Stäubli, etc.Also, companies like Mill-Max make connectors that will fit, though they may not be as deep as you want.With that said, the weight of the probe is likely too much for the SMD clips, and will just yank them off. I’d much sooner suggest making header (“DuPont”) to banana cables. Instead of actual “DuPont” female connectors, which aren’t very durable, use the female contacts for high-density D-sub connectors, or something even better like Mill-Max 0722, 3922, or 0306. I suggest using a thin silicone wire.

author: beanflying
author_rank: Super Contributor
timestamp: January 29, 2020, 07:03:33 am
content: Consider these from Frankie tooeBay auction: #171084548642
EM Test  ESD 30  -  rebuilding ground return cable - Page 1
Forum section: electronics / testgear

author: EE-digger
author_rank: Frequent Contributor
timestamp: January 25, 2020, 02:47:56 pm
content: I just made a high quality, flexible, low inductance replacement ground return lead for a commercial ESD simulator. There's one quandary in my own mind however.Using an old HP logic analyzer cable, I was going to tie all leads and the shield together at both ends. Then I got to thinking ... for the roughly 300MHz energy content of the ESD discharge, we're talking skin depth only.The 20 "encased" analyzer wires would be trapped within a Faraday cage (the braid). Would they even contribute to lower inductance at these frequencies?For now, I ended up cutting off the wires and using only the braid but could re-do the ends if it would give lower inductance.The ESD waveform delivered by simulators is dependent on the return lead. You will see everything from heavy gauge wire to flat ribbon cable (all tied at a plate at each end) used commercially. My braid-only is probably more than ok but my mind will not rest until I figure this out.added - re-titled to added a Test Equipment connection
FS: Datron 4000, 4000A, 4200, 470X and 480X extender cards - Page 1
Forum section: electronics / testgear

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: January 24, 2020, 07:47:47 pm
content: Please excuse the second post outside the Buy/Sell forum, I don't have a feel for which forums the test equipment aficionados scan....I have designed and built an extender card set for the Datron 4XXX series calibrators.It's a two card solution that covers all eight big cards. I have not yet worked out the cable extensions needed for the PA card cables for when the PA card is on the extender. I am going to look at possibly doing a breakout board for extending the cables and probing lines.Photos are attached of the extender card in action with the Digital/CPU card extended. As you can see the extender card flips the Datron card 180 degrees to allow probing of the test points on the card. It also allows direct probing of component pads and leads using the component views in the manual. Each edge connector line has a probe hook for scope or meter probes, all 120 of them!Please PM me if you are interested in purchasing a set.
System Emulator for developing/testing firmware - Page 1
Forum section: electronics / testgear

author: vaidasz
author_rank: Newbie
timestamp: January 23, 2020, 07:01:20 pm
content: Hi guys!How do you develop firmware for systems that lacks some of the auxiliary hardware?I'm writing firmware for custom board that will be incorporated in a bigger analog/digital system. Full system is unfortunately not available yet, but the deadlines are approaching quicklyMaybe you could recommend a way to emulate the whole system so I can test my firmware?System consists of some analog pressure gauges, valves, temperature sensors, heaters and some other boards connected.

author: tv84
author_rank: Super Contributor
timestamp: January 23, 2020, 07:06:25 pm
content: Looks like a chicken-egg paradox...

author: nctnico
author_rank: Super Contributor
timestamp: January 23, 2020, 08:15:12 pm
content: Quote from: vaidasz on January 23, 2020, 07:01:20 pmFunny. I have a similar project with hardware which sits at a customer and is dangerous to operate as well. I created a version (using define / ifdef) which can simulate the hardware in cooperation with relays connected to the outputs (the board senses whether an actuator is connected or not). The behaviour got fine-tuned over time but right now I have a simulation mode which pretty much mimics the real deal and allows me to run all kinds of tests.

author: TerminalJack505
author_rank: Super Contributor
timestamp: January 23, 2020, 08:50:00 pm
content: You might consider using a decoupling design pattern such as the publish-subscribe pattern or bridge pattern. This will allow for multiple implementations of the hardware--a real version and a "virtualized" version, for example.

author: james_s
author_rank: Super Contributor
timestamp: January 23, 2020, 09:15:10 pm
content: Can you build a test rig with pots for the sensors and LEDs for controlled devices?

author: ralphrmartin
author_rank: Frequent Contributor
timestamp: January 24, 2020, 05:28:40 pm
content: This may or may not be a helpful approach, but you could try modelling the system in something like Simulink, after characterising the bits of it that you already have or understand. You could then at least test your controlalgorithmeven if not the detailed code.
Recommend a Good DC Load? - Page 1
Forum section: electronics / testgear

author: bostonman
author_rank: Super Contributor
timestamp: January 23, 2020, 08:54:05 pm
content: I was browsing DC loads and found this: MakerHawk USB Load Tester 150W 200V 20ANot sure if anyone has input about it and/or a similar robust one that's cheaper.
no text - Page 1
Forum section: electronics / testgear

author: daywalkerdha
author_rank: Contributor
timestamp: January 22, 2020, 06:34:19 pm
content: no text

author: Fungus
author_rank: Super Contributor
timestamp: January 22, 2020, 07:07:26 pm
content: Calibration isn't the same as 'adjustment'.Calibration means using the meter to measuring a known value and noting the readings shown on screen, along with amount of error (eg. measure a 5.00000 volt reference and note that the meter says 5.001 on screen). They'll give you a calibration certificate that shows the value "5.001" in the box for that range.Adjustment is what they do at the factory, ie. they connect it to the 5.00000V reference standard then adjust the meter until the reading shown on screen is exactly 5.000.Calibration doesn't require opening up the meter. Adjustment does.

author: Gyro
author_rank: Super Contributor
timestamp: January 22, 2020, 09:11:42 pm
content: RS sell meters with various levels of 'Cal'. Vanilla manufacturer, RS Cal, and UKAS Cal. I've no idea what you get for your money with the RS Cal.https://uk.rs-online.com/web/c/?sra=oss&r=t&searchTerm=fluke+87

author: retrolefty
author_rank: Super Contributor
timestamp: January 22, 2020, 09:26:49 pm
content: The whole calibration Vs adjustment issue is a load of bull used to help keep some firms in the black. A more honest option would be to offer either 1. validation only or 2. adjustment and validation. Calling a validation a calibration is dishonest.

author: tautech
author_rank: Super Contributor
timestamp: January 22, 2020, 09:35:34 pm
content: Quote from: retrolefty on January 22, 2020, 09:26:49 pmOne other word that means the same thing and more commonly used IMO; verification.

author: tooki
author_rank: Super Contributor
timestamp: January 23, 2020, 06:23:33 am
content: Quote from: Fungus on January 22, 2020, 07:07:26 pmMost modern meters that aren’t cheapies, including the 87 V, use “closed box” adjustment accessed via menus. (Though it’s usually called calibration in the service manuals.) Calibration/adjustment via trimpots is hopelessly outdated technology.

author: LazyJack
author_rank: Frequent Contributor
timestamp: January 23, 2020, 07:58:57 am
content: Well, calibration in metrology context has always been "comparing to a known value", so it is correct to call it calibration.

author: tooki
author_rank: Super Contributor
timestamp: January 23, 2020, 01:54:05 pm
content: Yes, and in electronics generically it’s more widely understood to mean adjustment.

author: Fungus
author_rank: Super Contributor
timestamp: January 23, 2020, 07:17:37 pm
content: Quote from: LazyJack on January 23, 2020, 07:58:57 amQuote from: tooki on January 23, 2020, 01:54:05 pmThe stickers on the meter at the the top of this thread indicate the "metrology" definition, ie. The meter was originally purchased along with atraceablepiece of paper full of numbers.

author: blacksheeplogic
author_rank: Frequent Contributor
timestamp: January 23, 2020, 08:05:33 pm
content: Quote from: Fungus on January 23, 2020, 07:17:37 pmYou don't always get the full report, just that it 'passed' (measured values in expected range).
Reading and monitoring high voltages with Oscilloscope - Page 1
Forum section: electronics / testgear

author: vinlove
author_rank: Frequent Contributor
timestamp: January 21, 2020, 01:02:44 pm
content: I have this vintage tube device, and wanting to monitor voltage changes on the smoothing cap. It will rise about up to 600 DCV.And the transformer can put out about 800 ACV.Could I use an Oscilloscope for this task? What spec. of the scope is required?And maybe need some add-on device onto the probes?Or is it not possible? Maybe there are better tools to do it? I am not sure, I don't know much about the type of Oscilloscopes and their capabilities.I have been using a DMM, but thought it would be nice to see the changes of the voltages on the screen with the waves.

author: BravoV
author_rank: Super Contributor
timestamp: January 21, 2020, 01:10:51 pm
content: Use a HV differential probe, an example of the probe in action, the scope was measuring the mains line at 220 VAC that was powering it self.

author: tautech
author_rank: Super Contributor
timestamp: January 21, 2020, 01:30:04 pm
content: It's within the capabilities of a 100:1 probe for sure but be wary of the need of probe voltage derating with higher frequencies.Everyone should have at least one 100:1 probe for safely probing elevated voltages.

author: vinlove
author_rank: Frequent Contributor
timestamp: January 21, 2020, 01:53:23 pm
content: Are those probes expensive? Are they safety guaranteed? I dont want to blow up my scope.

author: tggzzz
author_rank: Super Contributor
timestamp: January 21, 2020, 03:25:27 pm
content: With standard 100:1 probes you have to be careful that the probe's shield is connected to somewhere "safe", since the shieldmust beconnected through the scope to the protective mains earth (PME). You also need to check the probe's voltage derating as a function of frequency.Some Dunning-Kruger candidates disconnect the scope's PME, thus exposing themselves and the scope to lethal voltages if something goes wrong or slips.Never ever float a scope!You haven't said yourobjectives, i.e. what you expect to learn from looking at the voltages. I strongly suspect there are better and safer ways of achieving your objectives - e.g. an appropriately rated voltmeter. Beware of very cheap voltmeters; frequently the rated voltages are a figment of a sales department's imagination.

author: luma
author_rank: Regular Contributor
timestamp: January 22, 2020, 07:24:12 pm
content: Quote from: vinlove on January 21, 2020, 01:53:23 pmI use the Micsig DP10013 differential probe set for poking my probes into higher voltage devices. For $150 you get the ability to poke your probes into 1000V+ while keeping your scope relatively safe from the sorts of issues noted above.

author: tautech
author_rank: Super Contributor
timestamp: January 22, 2020, 08:37:38 pm
content: Quote from: vinlove on January 21, 2020, 01:53:23 pmDefine expensive compared to something like an old CRO or a new DSO ?QuoteIf they have an official CAT rating, for sure they are safe.QuoteThat should be the least of your worries, personal safety is a higher priority IMHO.
Owon XSA1036 spectrum analyzer won't boot - Page 1
Forum section: electronics / testgear

author: swperk
author_rank: Regular Contributor
timestamp: December 21, 2019, 02:09:22 pm
content: I just purchased a brand new Owon XSA1036 spectrum analyzer. It arrived yesterday, and when I powered it up for the first time it got stuck on the splash screen and stayed that way for several minutes until I powered it back down. Restarting it got me the same splash screen and then a blank solid blue screen. Again, after waiting for several minutes, nothing changed. Every time I start it up it does one or the other of these two behaviors.It's the weekend, so I won't be able to contact the distributor until Monday. Just curious if anyone has seen this behavior, if there's some "magic" keypress sequence to force a restart, and/or if it's possible to refresh the firmware with the instrument in this condition.Thanks!

author: alpher
author_rank: Frequent Contributor
timestamp: December 22, 2019, 08:55:54 pm
content: Boy what a coincidence, I just got their XSA1015TG from Arrow, mine wont evenShow the splash screen, backlight lights up and that's that, blank screen.Bummer, will contact Arrow tomorrow, we'll see if they replace it.My guess is that the units were returns and never checked for operation before resale.

author: swperk
author_rank: Regular Contributor
timestamp: December 25, 2019, 04:50:16 am
content: I contacted Lilliput on Monday (Owon’s US tech support). They replied right away with an RMA and a free return shipping label. They received it today and I’ll let the forum know what happens.

author: swperk
author_rank: Regular Contributor
timestamp: January 08, 2020, 04:17:54 am
content: Owon replaced the main board in my XSA1036 and returned it to me by overnight shipping. It works perfectly now. I'm very pleased with Owon's products and their customer service!

author: alpher
author_rank: Frequent Contributor
timestamp: January 22, 2020, 07:41:03 pm
content: Hi, mine took a little longer.Eventually Owon/Liliput send me a replacement what they call "motherboard" for the unit.It took me ~30 min to replace and have to report that it seems to be working fine, finally !There's one issue though, when I turn the tracking gen. output ON the button does not light ?Is that normal behaviour or not, couldn't find anything about it in the manual ?Since I now have a spare "motherboard"unit, would you like a small teardown?
Comet Voltix-150 and Voltix-M High voltage X-Ray generator measurment equipment - Page 1
Forum section: electronics / testgear

author: KiraKiwaKilowatt
author_rank: Newbie
timestamp: January 22, 2020, 02:34:12 pm
content: Hi there,I have this baby at work a Comet Voltix-M and 2 Voltix-150 with the AC and DC probes.My assuming is that is for measuring the voltage (+/-150kV) at the output of a x-ray high voltage generator.Obviously I am working on the field (start-up) and the equipment was apparently picked up along the way. But no one known about it, and a search on the interweb did not help.So If anyone as a digital copy of the manual or can direct me to the website of the manufacturer, or have any information on the maximum input voltage or the IFU that would be great.[ Specified attachment is not available ]
JBC soldering station UI language setting - Page 1
Forum section: electronics / testgear

author: arny
author_rank: Newbie
timestamp: January 22, 2020, 10:11:16 am
content: I got a JBC soldering station model number CD-2SHQE, it came with a Chinese user interface. Is there any chance to change the UI language to English?I checked every menu in the UI and didn’t find a setting for the language.Thank you in advance.
OSCILLOSCOPE LEADER 4081= KENWOOD CS-5135 DOES NOT CHECK THE BRIGHTNESS OF THE T - Page 1
Forum section: electronics / testgear

author: quinoara
author_rank: Contributor
timestamp: January 20, 2020, 02:27:46 am
content: Dear Foristas, I am grateful in advance for some collaboration with this LEADER 4081 analog oscilloscope equal to the KENWOOD CS-5135. With failures with the brightness control, I have the service manual.Initially, when it was turned on, it took time to appear the stroke and when it appeared in 10 or 15 minutes, it did not let the brightness control.Initially, the operating voltages were checked, being all normal, note that when starting the ignition did not show high voltage, the high voltage section was checked and an isolated high-speed diode was found at one of the ends due to oxidation, in the Inten adjust circuit consisting of VR401, coming into operation correctly.The surprise came after armed and covered when a light was heard when a diode or resistance was broken, leaving the oscilloscope with excess brightness in the stroke and without intensity control this does not work.The X74-1490-00 card was checked thoroughly to see if something burst or burned I want to emphasize that no burning smell was felt, everything being in normal condition.Diode by diode, resistance by resistance, transistor by transistor, capacitors all manually with the ohmmeter were checked in detail, making different tests to verify the optimal state of each component, finding everything normal including the pot that controls the Focus intensity and astigmatism.The approach works normal and astigmatism control. It just does not control the brightness or intensity. Attached scheme and photo of the failure presented.I reiterate thanks for any suggestions.

author: shakalnokturn
author_rank: Super Contributor
timestamp: January 20, 2020, 11:36:37 am
content: Quote from: quinoara on January 20, 2020, 02:27:46 amYes, it would help. Did you forget?

author: quinoara
author_rank: Contributor
timestamp: January 22, 2020, 04:26:14 am
content: Download link service manualhttps://we.tl/t-x3dRSxH1ET
Sencore Test Leads - Page 1
Forum section: electronics / testgear

author: Brad808
author_rank: Contributor
timestamp: January 22, 2020, 03:20:18 am
content: Hey guys picked up a sencore ha2500 without test leads. I'll probably have to make my own (or if anyone knows where to get some let me know).Anyone know the construction of:Sencore 39G470 Load & Ringer Test LeadandSencore 39G469 Dynamic Test LeadI'm not so worried about 39G481 B+ Supply Lead since it's a direct lead.Not my pics but this is what they look like:
Sciaky model C.R.O.I. what is it? - Page 1
Forum section: electronics / testgear

author: (*steve*)
author_rank: Regular Contributor
timestamp: January 28, 2020, 01:28:24 pm
content: Here's my latest find for restoration. It looked interesting, but I don't know anything about it.It's 15.5 x 11.5 cm (x 11.5cm deep).Probably made in Australia. Capacitors are a mix of British and Australian made. Contains 2 x 6AM6 tubes and the display tube (so far unidentified). No obvious rectifier...Has someone snapped off banana plugs in the sockets?What the heck does it do?

author: tggzzz
author_rank: Super Contributor
timestamp: January 28, 2020, 02:26:19 pm
content: My guess is that it is a small, special purpose "cathode ray oscilloscope indicator".

author: james_s
author_rank: Super Contributor
timestamp: January 28, 2020, 05:12:00 pm
content: It's obviously an oscilloscope, a rather primitive one though I'd say.

author: (*steve*)
author_rank: Regular Contributor
timestamp: January 29, 2020, 10:17:45 am
content: I guess the tiny display tripped me up. It's the size of a magic eye tube. I can't imagine I'll see a lot of detail :-)Maybe there's some selenium rectifiers hidden inside it.

author: Gyro
author_rank: Super Contributor
timestamp: January 29, 2020, 01:11:47 pm
content: That looks pretty old! That Art Deco decoration around the CRT makes me think early '30s [EDIT: Although 6AM6s would make it late '40s, somebody had a taste for retro!]. When did Australia get 240V AC mains?It looks like an interesting restoration project - internal photos would be nice!If you do manage to get it working, I wouldn't trust the transformer Primary - Secondary insulation to be up to scratch. I would run it off an isolation transformer - to protect the transformer as much as anything. Yes, be prepared for Selenium, probably including the CRT anode supply! (look for a narrow srbp tube).

author: chris_leyson
author_rank: Super Contributor
timestamp: January 29, 2020, 01:30:00 pm
content: It's probably from the 1930s'. Frequency control would set the time base speed and the sync control would be adjusted to get the time base to synchronize or lock to the Y signal, if out of lock the time base would still run just like the auto setting. Before Tektronix invented the triggered time base, injection locked oscillators were used to generate the sweep and the sync control adjusted the amount of injected signal.

author: james_s
author_rank: Super Contributor
timestamp: January 29, 2020, 06:38:30 pm
content: Quote from: Gyro on January 29, 2020, 01:11:47 pmI dunno, I have a 1937 Philco console radio that I use regularly, never occurred to me to worry about the power transformer. Lots of other people running antique radios and other gear without transformer problems. I'd definitely replace any wax or electrolytic capacitors though.
HP 8568B IF Section A4A8 Q10 Part # 1855-0267 Replacement Recommedations - Page 1
Forum section: electronics / testgear

author: Sambo521
author_rank: Newbie
timestamp: January 20, 2020, 08:07:32 pm
content: Have a bad Q10 JFET (HP Part # 1855-0267) that I cant find any specs on and would like to be able to replace the thing.Looks like a 4416 may replace it but without the original specs I'm not sure.Any thoughts or suggestions are welcomed.Thanks
Hack Proskit MT1706 PeakMeter PM 18C , Bside ADM08A - Page 1
Forum section: electronics / testgear

author: rafik23
author_rank: Newbie
timestamp: January 21, 2020, 12:59:54 am
content: After going home i take the multimeter it is a PROSKit MT 1706 and start reading again and again on forums so I decide to teardown it and make an analysis of data stored in eeprom and hack it EEprom from originaly dump appears like thiswe see on its dump no thing extra or strange so i decide to make an excel file to analyse data stored in eepromi take an hexa from editer and past it on data in excel and i see the max range , and all data relative to manufactorI take my old programmer type CH341A and its onboard IC clamp, after more reprise it didnt success reading then i went to solder on PCBand starting reading and modifing data function from 01H to 40H like we see on my older post there is function above 30Hand the result isRANGE Code Func position Hex---------------------------------------600 mVDC 01 08 0360 VAC 0A 08 09600 VAC 0B 08 0A750 VAC 0C 08 0C60 mA DC 29 08 0E 0F mA DC AUTO 11600 mA DC 2A 08 0F60K OHM 17 09 09600 OHM 15 09 0BNCV 22 08 056 VAC 09 08 08HLive 24 08 0DHz 1D 8 0FCont 14 8 1C1000VDC 06 9 00600 VDC 05 9 0160 VDC 04 9 0260 A DC 2E 9 036 VDC 03 9 0460 A AC 30 9 05600mA AC 2C 9 066 M OHMS 19 9 07600KOHMS 18 9 086K OMM 16 9 0A° C 1F 9 0DHfe 21 9 0EDiode 13 9 1C600 mVAC 08 07 AUTO 3360MOHM 1A600MOHMS 1BCap 1C% 1E°F 20600 uA DC 25 0D µADC AUTO6 mA DC 26600 uA AC 27 0E µA AC AUTO6 mA AC 2860 mA AC 2B 10 mA AC AUTO6 A DC 2D 11 A DC AUTO6 A AC 2F 12 A AC AUTO 3660 uA DC 3160 uA ACINFO the function is mentioned in right is the same range in AUTO modeafter this i change max range to 9999 count and over range OL is 10000after this i try to add some button like REL/RS232 and other but nothing hapened when switching.I think for automatic ranging there is something added on data in the header of eepromExample : we seeit not described on DTM0660 datasheetso i add on some range the same range in automode but i discover only Amper range can be in auto mode ( no volt no Ohms )here is structure of 80h and BFh0x80H 00 00 24 01 00 22 1a 19 09 0a 0b 21 0c 31 29 2a 06 05 04 2e 03 30 2c 2b 18 17 16 15 14 1f 1c 1d0xA0H 00 00 00 07 00 00 00 00 00 00 00 00 00 0d 0f 00 00 00 00 00 00 00 00 10 00 00 00 00 13 20 00 1eI have added600mvAC on 600mvDC (not modified but ADDED)60mADC AUTO on 60 mA DC60mADC AUTO on 60 mA DC600µADC AUTO on 60µA DCthat's allany other idea ? or suggestions ?dumps of orginal and modified
Keithley 6167, 10M resistor in parallel with wire? - Page 1
Forum section: electronics / testgear

author: gamalot
author_rank: Super Contributor
timestamp: January 16, 2020, 12:38:04 pm
content: When I opened the case of my Keithley 6167, I was shocked by a 10M ohm resistor crossed two terminals those shorted by a thick bare wire.So I went to the manual of 6167, and yes, the resistors and wires were indeed connected in parallel. I have no idea what the purpose of this is.

author: HighVoltage
author_rank: Super Contributor
timestamp: January 16, 2020, 05:01:23 pm
content: I have seen some weird circuits in older Keithley instruments over the years but not a wire parallel to a 10M resistor. Interesting find and I am not sure why this configured as such.

author: Tomorokoshi
author_rank: Super Contributor
timestamp: January 16, 2020, 05:40:55 pm
content: Perhaps for unit testing partway through the assembly process. At a later stage the wire is added in parallel.

author: Damianos
author_rank: Frequent Contributor
timestamp: January 19, 2020, 11:21:20 am
content: It may be there for other uses. For example as an added protection, for voltage measurements, if you cut the wire.Have you the manual or instruction sheet?
Proskit MT-5211 rotary switch - Page 1
Forum section: electronics / testgear

author: kwinborne
author_rank: Newbie
timestamp: June 02, 2019, 01:09:44 am
content: Hello everyone! My name Kiyle. I am needing a bit of help.My Proskit MT-5211's rotary switch came off in the process of double checking the meters safety, and while I am pleased with the quality, I accidentally pulled off one of the little copper contacts that sit on the rotor.Does anyone have a photograph of the rotary switch contacts? preferably both sides?Thanks!- Kiyle

author: shakalnokturn
author_rank: Super Contributor
timestamp: June 03, 2019, 12:59:38 am
content: Tried searching?https://www.eevblog.com/forum/testgear/inside-of-proskit-mt5211-lcr-meter/

author: leogenic
author_rank: Newbie
timestamp: January 20, 2020, 09:00:11 am
content: I have the same problem, accidentally detached the copper pins and not sure the correct location to put back. Can you please share with me the findings. Thank you.
Looking for software/data -  Airflow Lufttechnik Digital Barometer DB2 - Page 1
Forum section: electronics / testgear

author: nfmax
author_rank: Super Contributor
timestamp: January 19, 2020, 10:20:41 pm
content: I have a battery powered digital barometer DB2 from Airflow GmbH. This has a serial output for data logging, but the output format is proprietary/undocumented. Unfortunately, I no longer have the original logging software, which was called 'MWelk' If anyone out there has one of these instruments, and a copy of the software (or documentation on the data format) they could provide me with I would be most grateful(prompted because the weather forecast for tomorrow shows the pressure here exceeding 1050 mBar for the first time since 1957!)
Siglent SPD3303X-E binding post spacing fixed? - Page 1
Forum section: electronics / testgear

author: petert
author_rank: Regular Contributor
timestamp: January 19, 2020, 09:25:49 pm
content: Hi,I am aware of the following post, but I wonder if the binding post spacing is fixed in people having bought the Siglent SPD3303X-E recently.https://www.eevblog.com/forum/testgear/siglent-spd3303x-binding-post-issue/msg2504730/?topicseen#msg2504730

author: tv84
author_rank: Super Contributor
timestamp: January 19, 2020, 09:28:45 pm
content: If you are aware, why don't you ask in that thread?

author: petert
author_rank: Regular Contributor
timestamp: January 19, 2020, 09:46:49 pm
content: After a while, people usually consider a thread to be closed due to time that passed.QuoteBut ok, I'll do.
Need a recommendation for test fixture components **Solved** - Page 1
Forum section: electronics / testgear

author: t1d
author_rank: Super Contributor
timestamp: January 19, 2020, 04:41:35 am
content: I am building a DIY Curve Tracer. I need quick disconnect fixtures for individual Discretes, BJTs and MOSFETs... So, two pole and three pole... That will clamp down on the DUT pins... Using levers, or push buttons... I would rather stay away from screw clamps... Panel mount. Specific model numbers would be great.The WAGO line looks good, but the clamps are for wires and I am concerned that they will not close adequately on the thin component pins. And, where to buy them... Mouser doesn't seem to have them???I have thought about DIYing this... Three conductive springs with a cap across the top and individual signal wires underneath... Push the cap back to cause the springs to flex open. Insert the legs of the DUT. Release to clamp.But, are there conductive springs that would accept solder and not introduce excessive resistance? If so, do they have a specific name? Retailer?Suggestions, please and thank you.

author: t1d
author_rank: Super Contributor
timestamp: January 19, 2020, 08:02:13 am
content: I came up with a simple solution that is compact, cheap and easily sourced... A 16 Pin ZIF. Here's my layout. It allows two components to be compared, or matched.
B3603 Buck Module Alternative - Page 1
Forum section: electronics / testgear

author: picandmix
author_rank: Frequent Contributor
timestamp: November 29, 2019, 04:25:53 pm
content: Hi,Looking to knock up another simple psu like the existing B3603 module reviewed by Rick Law in this forum some years ago.Seems the B3603 is still available from China for around £7 /$10 but wondered if some of the newer modules around the same price would be a better buy ?Unable to find any details of what chips these newer ones use or any reviews of them.Any suggestions for a suitable alternative or worth the wait for a B3603 from China..?

author: flywheelz
author_rank: Regular Contributor
timestamp: January 18, 2020, 11:47:46 pm
content: Hi, did you end up getting the newer 5a supply? It seems to not able to count capacity. The B3603 seems like a better choice imo.

author: nardev
author_rank: Unknown
timestamp: January 19, 2020, 12:14:56 am
content: Price range?I had DPS3005 even before any PSU. Was very fine. Though i had some nice meanwell with it.
RIGOL DS1054Z Battery Power  - Page 1
Forum section: electronics / testgear

author: roger101
author_rank: Newbie
timestamp: January 18, 2020, 01:45:57 pm
content: Hi all. New to this forum. Was looking at the teardown of the RIGOL DS1054Z on youtube and Dave suggested tat there might be space for a battery solution in the PSU compartment. Has anyone done this already?Ideally, I'd like to power the thing from a Makita 18v 6ah battery. I've always got these knocking around in the field and have bought some battery holder units from someone who 3D prints them. So if the DC side of the unit was less than 18V, this might be doable, with a seperate connector. Not ideal for everyone, but would suit my requirements OK.Does anyone know what the DC side voltage is? I Should point out that I haven't bought the RIGOL yet, otherwise I would have looked myself.Also, been looking at the DS1202Z-E instead of the 1054, as I don't need 4 ch and the 200MHz bandwidth is more useful. Anyone tried one out.Cheers

author: ebastler
author_rank: Super Contributor
timestamp: January 18, 2020, 02:03:27 pm
content: Some prior experiences and discussions can be found here:https://www.eevblog.com/forum/testgear/battery-pack-for-rigol-ds1054z/msg717702/#msg717702https://www.eevblog.com/forum/testgear/made-a-battery-for-my-ds1054z-20hr-batt-life/msg887061/#msg887061(The forum's search function does work resonably well. Just be sure to search from the home page if you want to search the whole forum. If you are already looking at a sub-forum, the search will be limited to that one. Alternatively, use Google with the "site:eevblog.com" qualifier.Edit: Youcanselect "search the whole forum" from a dropdown menu next to the search field, even when starting a search from within a sub-forum or topic. The search just defaults to the smaller scope. I have been bitten a few times by overlooking that default setting, and have hence made it a habit to start searching from the home page...)

author: roger101
author_rank: Newbie
timestamp: January 18, 2020, 03:30:38 pm
content: Thanking you. I did a brief search, but not too hard. Excellent stuff
Atlas Peak LCR45 reports low values - Page 1
Forum section: electronics / testgear

author: wwoofbum
author_rank: Newbie
timestamp: January 17, 2020, 08:53:11 pm
content: I recently received an Atlas Peak LCR45. Doing some initial investigation of various passive components I find resistance and capacitance values consistent with the values specified by the component manufacturers, but consistently low values for inductance. Testing 18 commercial inductors with values from 150 uH to 1000uH, and two litz wire wound ferrite core coils, I get errors from -9% to -36%. All inductance measurements were made by the meter at its 200kHz frequency. The trend is for generally smaller error as nominal (and measured) inductance increases.I have also conducted the procedure for probe compensation, with no change in outcome.I am by no means experienced with inductance measurement, so it is possible that I am, somehow, doing it wrong.Is there a means by which I could conduct a test that would show, more conclusively, that the meter is not correctly reporting inductance? Is this something I should take up with the manufacturer of the meter?Your advice will be appreciated.

author: tautech
author_rank: Super Contributor
timestamp: January 18, 2020, 07:47:48 am
content: Quote from: wwoofbum on January 17, 2020, 08:53:11 pmNew or used ?Quote from: wwoofbum on January 17, 2020, 08:53:11 pmFirst thing that comes to mind is what was the manufacturers test frequency for the commercial inductors ?Their datasheets will give clues.

author: PTR_1275
author_rank: Frequent Contributor
timestamp: January 18, 2020, 09:03:56 am
content: Most of our power inductors at work are specified at 1kHz despite being used at frequencies up to 200kHz.What are the part numbers of the inductors you’re testing?

author: wwoofbum
author_rank: Newbie
timestamp: January 18, 2020, 02:47:43 pm
content: Perhaps this is merely a cautionary tale about buying stuff from China. In further investigation, I prepared a tank circuit with a (nominally) 100 uH inductor, and a 0.088 uF capacitor (nominally 0.1 uF, also from China). Oscilloscope reported a resonant frequency of roughly 59 kHz which, calculation suggests, indicates a value of about 82 uH for the inductor. Testing of this same inductor with the LCR45 gave 78 uH, significantly less error (relative to its measured, not nominal value) than the 9-20% deviation reported above (and given the potential error of the capacitor, not all that far from the 1% error specification for the LCR45 at that value).I suppose that I should not be surprised, given my tendency to buy stuff off ebay, thatallof the inductors I have in my kit measure below their nominal value. In life (I'm retired, now) I was a cook. In one memorable incident, I purchased an inexpensive "1 cup measure" that was manufactured in China. It had all the proper markings on its clear plastic: 1/4c, 1/2c, 3/4c, 1c, and marks at 1, 2, 3, 4, 5, 6, 7, 8 ounces. Unfortunately the actual volume at the 1 cup mark, compared with other, more reliable measures, was somewhere above 9 fluid ounces.
DP832 overvoltage protection issue - Page 1
Forum section: electronics / testgear

author: Redeeman
author_rank: Contributor
timestamp: January 16, 2020, 08:40:58 pm
content: I have a DP832 with model hacked into DP832A (though i highly doubt this influences anything)I notice that when setting the OVP to for example 12.1v, if i then go back and ramp the voltage up very quickly, the voltage shoots significantly above 12.1v before the output is turned off. I havent measured how much or how long, but I had a 12v fan connected, and it was enough that i was able to hear it spin up to a significantly higher RPM for a moment.This is a bit surprising, wouldnt it be completely sensible to expect the OVP to not even allow the user interface to set a higher voltage to begin with? am I missing something?

author: thm_w
author_rank: Super Contributor
timestamp: January 16, 2020, 11:07:20 pm
content: I believe it is software controlled, so it can be very slow to respond.Code seems non-optimal if its letting you set it above the OVP level, but there may be reasons for that. The RD6006 I have behaves similarly, and apparently many other supplies.https://www.eevblog.com/forum/testgear/rigol-dp832-ovp-overshooting-with-huge-delay/

author: Redeeman
author_rank: Contributor
timestamp: January 17, 2020, 06:26:30 pm
content: would be interesting to know what (if any) reasons there are for the software to allow setting of higher output than OVP is set to. I really can not see a reason

author: RoGeorge
author_rank: Super Contributor
timestamp: January 17, 2020, 06:49:14 pm
content: The software does not want to allow over voltage to happen, but this is the best it can do.To detect over-voltage, it first need to measure the voltage. Most probably it's not made at a single ADC measurement, but a few reads are averaged over a period of time for a better resolution (oversampling). Then, there are many other things that need to be run by a single processor, not only the OVP subroutine, so the subroutine that compares the voltage needs to wait it's turn to be run.All these takes time, and by the time the software decides to shut down the output, the output voltage might have already overshoot a lot.

author: TurboTom
author_rank: Super Contributor
timestamp: January 17, 2020, 07:11:05 pm
content: Quote from: Redeeman on January 17, 2020, 06:26:30 pmImagine you want to constant-current charge a battery (reverse current blocking diode required and threshold voltage considered) and you'ld like to use the voltage limit to terminate the charging process. This would required initially setting a higher output voltage, otherwise the limit voltage would never be reached since the PSU would switch over to constant voltage mode before.There may be other application where being able to set a higher output voltage than the limit, and being permitted to enable the output, makes absolute sense.... just my two cents...