hybridfree/eevblog-posts huggingface dataset:
Siglent SDS1102CNL - Page 1
Forum section: electronics / testgear

author: cosmicray
author_rank: Frequent Contributor
timestamp: December 26, 2014, 08:49:39 pm
content: New member, new poster, etc. Just received a Siglent SDS1102CNL a few days back. This is my first experience with a DSO.One thing that jumped out at me is the level of 'chatter' displayed at the top of bottom of the square wave test signal. Is this normal on a DSO of this type ? The chatter seems to be the same height regardless of how much I expand the vertical.s/w vers 5.01.01.11h/w vers 11-62-3.5unit was drop shipped from a warehouse in Ohio (presumably a factory depot)

author: tautech
author_rank: Super Contributor
timestamp: December 27, 2014, 12:00:40 am
content: Welcome to the forum.This is quite normal in the SDS1000 series.The displayed waveform can be "cleaned up" for veiwing pleasure in a number of ways.PersistanceAverageingBandwidth limit filterI understand as it is your first DSO it appears alarming but most DSO's do this to some degree.It is the nature of the beast.Some of the chatter is noise, some enviromental, some internal.Our Dave did a video on DSO noise, see if you can find it.As time has gone by I have learnt to ignore it and just use the scope and this would be my advice long term.Better to concentrate on safe and proper use and application of the features your DSO can provide.Spend some time here:https://www.eevblog.com/forum/beginners/oscilloscope-training-class-(long)/and here:https://www.youtube.com/w2aewBut you can "tune" it out if you must.
HP / Agilent 08672-60187 Attenuator - Page 1
Forum section: electronics / testgear

author: Rick
author_rank: Frequent Contributor
timestamp: December 23, 2014, 12:42:33 am
content: Hi,I have purchased that attenuator on ebay and it was advertised as a 10 dB attenuator but it only halves the amplitudes.Does anybody have the exact attenuation value of that device?Apparently it came out of an HP 8672A synthesized signal generator.Thank you in advance.

author: larry42
author_rank: Regular Contributor
timestamp: December 23, 2014, 12:52:23 am
content: Are you measuring with 50ohm source and load impedance? To test if the attenuator is OK, measure the DC resistance through and each leg to ground, that should allow you to calculate the resistance values.

author: larry42
author_rank: Regular Contributor
timestamp: December 23, 2014, 08:59:55 am
content: Hmm, What is the center to centre resistance?

author: PA0PBZ
author_rank: Super Contributor
timestamp: December 23, 2014, 05:57:46 pm
content: QuoteThat all makes sense for a 6 dB 50 ohm attenuator
Tagarno microscope useless for board inspection in my view - Page 1
Forum section: electronics / testgear

author: Bob S
author_rank: Contributor
timestamp: December 24, 2014, 01:40:12 am
content: I was looking into the Tagarno microscope that Dave has and learned from Tagarno that there is no height adjustment so if your board has components that are too tall to focus you cant without putting the stand on some books or extending the camera off the bench and hand holding the board (yes, THERE solutions). This does not sound like a well thought out microscope for $4500.00++ Very disappointing. If anyone knows of a similar but more usable unit, please let me know.

author: rx8pilot
author_rank: Super Contributor
timestamp: December 24, 2014, 02:17:05 am
content: It looks like a solid travel range on the website? What are you talking about? How tall is your PCB?

author: Bob S
author_rank: Contributor
timestamp: December 24, 2014, 03:20:39 am
content: Some double sided boards can have tall capacitors, transformer, heatsinks etc on one side and a lot of SMDs on the other. The demos on the web are with single sided looking boards lying flat on the bench. What if you need to hold the board at an angle to side inspect? Just going by what I see and what the company has told me.If there is a published specification for the usable focus range, I would like to see it.
Rigol DG1022 vs DG1022A material differences - Page 1
Forum section: electronics / testgear

author: dadler
author_rank: Unknown
timestamp: December 26, 2014, 09:37:12 am
content: Note: I have done copious searching and have not located relevant information on this topic (unless you consider archived posts recommending "do a search" relevant information).Link to spec sheet:http://www.tequipment.net/assets/1/26/Documents/Rigol/DG1022A/dg1022a_doc_9.pdfQuestions:- Beyond the raw numbers in the specs, are there substantive differences between these models (DG1022 vs DG1022a)?I consider substantive differences to be things of the sort:any noteworthy changes to the internals?any changes affecting reliability/longevity?screen quality?fan noise?etc?- The DG1022 is still on the Rigol website, but it seems it's been around for a while now--and I have seen mention here and there that it may or may not be discontinued at some time in the past or future. I suppose this is all guesswork, but is this essentially an orphaned product? Or maybe there are still NOS units on the shelf? Asked another way: is this product (DG1022) still being manufactured?- The $120 price premium is small in absolute terms, but large in relative cost. Does +5MHz sinusoidal, +2MHz pulse, +350kHz triangle indeed warrant a 30% price premium, or is there another story here? Were these units priced differently earlier on?Thanks in advance for any direction.
NI USB 6008 - Page 1
Forum section: electronics / testgear

author: fostersimported
author_rank: Newbie
timestamp: December 21, 2014, 08:14:51 pm
content: I have gotten hold of a NI USB-600.Is there any other software other than LabView that i can use with it?Thanks in advance.

author: jeremy
author_rank: Super Contributor
timestamp: December 21, 2014, 08:19:45 pm
content: Yep, you can use the daqmx drivers with C/vb.net/C#/Python.
Hantek1062B  or Siglent SHS806  handheld DSO - Page 1
Forum section: electronics / testgear

author: Cauf
author_rank: Newbie
timestamp: December 22, 2014, 10:25:38 am
content: HiCan anybody give advice ( review) on one of these ?Which one to buy , as they have about the same specs.Reading good about the Hantek but don't find much on the Siglent.ThxPatrick
I think my DS1054z is broken :-( - Page 1
Forum section: electronics / testgear

author: JJalling
author_rank: Unknown
timestamp: December 20, 2014, 10:44:36 am
content: Hi all,I was about to use my Rigol DS1054z this morning, but when I turn it on, it is stuck at the bootscreen.After a while, the LEDs behind the CH1-4, MATH & REF buttons turn on.Oh man, my vacation has just begun :-(Has anyone experienced similar behavior from their scope?BR Jonas

author: kwass
author_rank: Frequent Contributor
timestamp: December 20, 2014, 04:14:51 pm
content: I haven't had any problems with my DS1054z but what you describe sounds somewhat similar to what other people have described after updating to the beta version of the firmware released (then withdrawn) a few weeks ago. Mostly they're talking about keyboard lockups but possibly you're experiencing some other type of lockup. They found that booting with the firmware on a USB stick got them going again. Read through the posts in the middle section (the page I linked to +/- a few pages) of this thread for more details:https://www.eevblog.com/forum/blog/eevblog-683-rigol-ds1000z-ds2000-oscilloscope-jitter-problems/495/Not sure that this will help, but I don't think it can hurt.

author: JJalling
author_rank: Unknown
timestamp: December 20, 2014, 08:33:33 pm
content: Hi Kwass,Thanks for the input. I don't think i can downgrade my scope. The Power-on + help trick doesn't work.BR Jonas

author: leppie
author_rank: Frequent Contributor
timestamp: December 20, 2014, 08:50:27 pm
content: Like kwass said, this sounds like the beta FW. Normally a power cycle or 2 fixes it. I have the same issue.

author: JJalling
author_rank: Unknown
timestamp: December 21, 2014, 10:01:36 am
content: I fixed it by upgrading the firmware via. usb.Thanks.BR Jonas

author: nixfu
author_rank: Unknown
timestamp: December 21, 2014, 10:47:12 am
content: Beta/Experimental FIRMWARE is much much much more risky than installing a beta piece of software that is easily re-installed, replaced, restored etc.

author: JJalling
author_rank: Unknown
timestamp: December 22, 2014, 04:39:04 am
content: I'm not sure what the intention of you message is, but I'm not trying to recommend people to upgrade their firmware!I have never upgraded the firmware on my scope before.Like I said before, my scope wouldn't turn on, so I contacted the shop I bought it from, and asked if they had any solution to my problem. They sent me a firmware file along with a guide on how to install it, and asked me to try it out, before returning my scope - it fixed my problem.But no. If it ain't broke, don't fix it.Br Jonas
UNI-T UT61E capacitance measurement inaccuracies ? - Page 1
Forum section: electronics / testgear

author: warrior_
author_rank: Newbie
timestamp: December 20, 2014, 06:10:40 pm
content: Yesterday i received my new UT61e from ebay and the capacitance measurement gives two different values on the same cap with autorange and manual ?Also the idle value with nothing connected on auto reads around 0.286 nF ?1000 uF 12V on auto reads 0.9108 mFon manual (2 presses) reads 0.881 mFim confused its seams like my caps are bad and good at the same timeI have a youtube video of the measurement , can anybody explain what is going on ?https://www.youtube.com/watch?v=XKrToVdBgbo&feature=youtu.be

author: torr032
author_rank: Regular Contributor
timestamp: December 20, 2014, 06:34:27 pm
content: Yes I saw on taobao, buyers are complaining something about capacitance with this new model with improved input protection. On old model it should be 60 pf ghost capacitance no leads connected, on new one it is higher around 300 pf.Where did you bought it, if it is from ebay can you tell from what seller?

author: warrior_
author_rank: Newbie
timestamp: December 20, 2014, 07:16:14 pm
content: Yes its the new model, i bought from geiliable-store.Is there any fix or hack for this and what is causing the fluctuationsthis is the new pcb layout

author: PA4TIM
author_rank: Super Contributor
timestamp: December 20, 2014, 07:31:30 pm
content: A multimeter is no LCR meter. Most multimeter charge a cap with DC and measure the time it takes. Try it again but short the cap before the measurement. If it holds charge from the first measurement the second one will be wrong.Besides that it also gets fooled by ESR. Increasing ESR and decreasing capacitance can cancel each other out so the cap looks good but is not.But hey, better as nothing and do not expect to much, it is a Unit-T

author: Wytnucls
author_rank: Super Contributor
timestamp: December 21, 2014, 08:11:24 am
content: By pressing 'Manual' twice, you end up on a higher range, with a shorter charging cycle and less accuracy.Protection is still to a low standard. No spark gaps or MOVs, no fusible resistor and same old 250V fuses.

author: PA4TIM
author_rank: Super Contributor
timestamp: December 21, 2014, 08:37:43 am
content: http://www.pa4tim.nl/?p=3331At the bottom of this page I made about cap testing is the result of a test on several bad caps measured in several ways by a tv repairman and in several ways by me.

author: warrior_
author_rank: Newbie
timestamp: December 21, 2014, 10:35:57 am
content: These are capacitance specs for UT61e.Can somebody confirm that the new version UT61e is out of spec ?

author: Wytnucls
author_rank: Super Contributor
timestamp: December 21, 2014, 12:51:59 pm
content: Brand new electrolytic caps can be 20% out on capacitance, so get an LCR meter if you want the true value, measured at 120 Hz, like the datasheet says.
ManualsPlus going out of business - Page 1
Forum section: electronics / testgear

author: motocoder
author_rank: Unknown
timestamp: December 21, 2014, 04:57:41 am
content: I got a letter from Manuals Plus saying there are closing down and are accepting reasonable offers for their existing stock of manuals. If you've got some old test equipment for which you'd like a printed manual, it might be worth checking there.http://www.manualsplus.com/I have no relation with this company other than I bought a manual from them once.
rf signal generator question - Page 1
Forum section: electronics / testgear

author: croyleje
author_rank: Regular Contributor
timestamp: December 20, 2014, 02:33:53 am
content: hello everyone,i just have a simple question i don't know much about RF but i need to align an IF filter and the directions say to input a 10MHz signal. i don't have an RF signal generator but i do have a function generator that goes to 10MHz would that work? i understand there wouldn't be any of the harmonics, but i think i can also get access to a function gen that has AM modulation also any thoughts on weather the function generator would work in place of a RF signal gen?thanks for the input,Jason

author: w2aew
author_rank: Super Contributor
timestamp: December 20, 2014, 02:50:49 am
content: Quote from: croyleje on December 20, 2014, 02:33:53 amYes, in general it will work fine. RF signal generators are usually higher performance than function generators (lower phase noise, less harmonic content, wider output amplitude control range, wider frequency coverage, etc.). But, for simple IF alignment tasks, a simple function generator will often work perfectly well.

author: croyleje
author_rank: Regular Contributor
timestamp: December 20, 2014, 02:56:14 am
content: thank you w2aew my thinking was it would but just wanted to run it past someone with more RF experience then me. a cheap RF sig gen is basically just outputting a sine wave anyway but wasn't sure if the harmonics would effect the alignment or not.thanks again,Jason
help me choose, BM857 vs UT71D - Page 1
Forum section: electronics / testgear

author: argg
author_rank: Contributor
timestamp: December 19, 2014, 04:59:17 pm
content: I currently have a Protek 505 and a Hewlett Packard 974A and they have been serving me flawlessly for many years. However I am in need of one with a high count and after browsing through the excellent Multimeter spreadsheethttps://www.eevblog.com/forum/testgear/multimeter-spreadsheet/I narrowed down my search to Brymen BM857 and Uni-T UT71D, both within my budget.They are two different animals, the Brymen looks old fashioned but as I read here the brand has a very good reputation for quality. On the other hand the Uni-T is a modern MM with all bells & whistles plus dual display but Uni-T as brand is occasionally scoffed because of quality issues.Which one would you choose? precision and longevity are my prioritiesthanks

author: PedroDaGr8
author_rank: Super Contributor
timestamp: December 19, 2014, 05:13:07 pm
content: Hands down the BM857, not even a second thought. I had a greenlee rebadged BM859 (the BM857 big brother) before and the internals are DAMN good. Fluke level of quality.I'm a big fan of Uni-T for what they are. Cheap, affordable, and decent quality at a good price point. The BM857 blows all of these out of the water, its safe, high high build quality, true precision, etc. It's not even a ball park comparison.

author: Lightages
author_rank: Unknown
timestamp: December 19, 2014, 06:04:12 pm
content: The only way to recommend the UT71D over the BM857 (you should get the new verison BTW, BM857s which has the updated design to meet current safety specs) is if you can't spend more money and want the PC connection and software. The UT71D comes with this as standard whereas the BM875s has it as an extra cost option of around $50.Other than that, the BM857s is a giant leap in built quality, safety, and reliability.

author: argg
author_rank: Contributor
timestamp: December 19, 2014, 06:47:38 pm
content: thank you guys, you make my choice easier

author: retiredcaps
author_rank: Super Contributor
timestamp: December 19, 2014, 07:53:43 pm
content: Martin did a review on the UT71DDave did a video on the Brymenhttp://www.eevblog.com/2013/02/28/eevblog-432-brymen-multimeters/

author: argg
author_rank: Contributor
timestamp: December 19, 2014, 08:08:12 pm
content: Quote from: retiredcaps on December 19, 2014, 07:53:43 pmyes, I have seen this and Dave's reaction to the silly backlight is reallyI read somewhere they have fixed it since then, can't remember where. Hopefully so otherwise the backlight is totally useless.Thanks for the UT71D links, I'll have a look on these too

author: Wytnucls
author_rank: Super Contributor
timestamp: December 19, 2014, 08:11:28 pm
content: Martin also did a review of the Amprobe AM-160, similar the Brymen BM857:
Hioki 3805-50 - Page 1
Forum section: electronics / testgear

author: HighResolution
author_rank: Contributor
timestamp: December 19, 2014, 10:25:25 pm
content: Hello all,I am an Electrical Engineering student who is looking to get some decent entry level gear for hobby level use. First thing I am looking at picking up is a DMM and am looking at the $200 range and I'm hoping to get something of good quality that will potentially last me a long time.I have been looking at the very useful spreadsheet and saw two DMM's with very similar price and specs/features and they are the Agilent U1242B and the Hioki 3805-50. Now the Agilent has good reviews but I could not find any feedback for the Hioki.I was hoping that someone had some experience with it and could share it here. I would also appreciate other comments/suggestions which would help me choose between these two DMM's.Thank you

author: retiredcaps
author_rank: Super Contributor
timestamp: December 19, 2014, 10:45:47 pm
content: Quote from: HighResolution on December 19, 2014, 10:25:25 pmThe 3804-50 might be close enough to give you a rough idea?https://www.eevblog.com/forum/reviews/hioki-3804-50-multimeter-teardown/BTW, be prepared for a flood of opinions from people with a $200 budget.

author: zaoka
author_rank: Frequent Contributor
timestamp: December 19, 2014, 10:48:15 pm
content: Get new version of HIOKI meter, they are much better design and superior quality.

author: HighResolution
author_rank: Contributor
timestamp: December 19, 2014, 11:13:24 pm
content: Quote from: retiredcaps on December 19, 2014, 10:45:47 pmThanks for that, I didn't think of searching for similar models. And I welcome any suggestions as I have very little knowledge on this subject.Quote from: zaoka on December 19, 2014, 10:48:15 pmThanks. I guess I will not be getting the 3805-50. I have looked at the newer DT4253 but the Agilent seems to have better specs/features for a similar price.

author: zaoka
author_rank: Frequent Contributor
timestamp: December 20, 2014, 01:14:34 am
content: I owned both HIOKI meters and did teardown on both. New HIOKI is way better from 3804-50... its way faster, has latched continuity (Agilent does not have), and quality is way better.What specs are you missing with DT4253?

author: HighResolution
author_rank: Contributor
timestamp: December 20, 2014, 01:37:42 am
content: Quote from: zaoka on December 20, 2014, 01:14:34 amNothing specific, the Agilent just has higher count and better accuracy for a similar price. I'm just trying to get the best meter in the $200 price range.Thanks for helping me out by the way.
Antique Meters - Page 1
Forum section: electronics / testgear

author: David_AVD
author_rank: Super Contributor
timestamp: December 17, 2014, 02:55:41 am
content: I got these meters (and a few other bits) from a fellow Aussie.Way before my time but great pieces.

author: tautech
author_rank: Super Contributor
timestamp: December 17, 2014, 03:16:04 am
content: Isn't the fob watch style one delightfull.Got a few AVO's when I was repairing CRO's especially for their 2.5 & 3 KV ranges.

author: radhaz
author_rank: Regular Contributor
timestamp: December 17, 2014, 03:17:05 am
content: Great stuff. Any plans on a tear down?

author: David_AVD
author_rank: Super Contributor
timestamp: December 17, 2014, 04:13:01 am
content: I love the fob watch style one too. Almost a work of art!The previous owner didn't want them any more, so I put my hand up to stop them going to the tip.No plans for a tear down just yet. Will have to see about that when I get some free time.

author: rstoer
author_rank: Regular Contributor
timestamp: December 17, 2014, 12:58:33 pm
content: What's the CAT rating on that watch fob meter?

author: macboy
author_rank: Super Contributor
timestamp: December 17, 2014, 01:20:36 pm
content: Quote from: rstoer on December 17, 2014, 12:58:33 pmI think that would be CAT 0. Nil. Nada.

author: anachrocomputer
author_rank: Regular Contributor
timestamp: December 17, 2014, 02:00:37 pm
content: My grandfather was chief engineer at a hospital in Colchester (Essex, UK). He had a meter like that fob-watch one, which I recall in my dad's garage in the 1970s. Wish I knew what happened to it! But it's a bit scary having 120V DC on that prong, right next to the metal case. Yikes! How do you hold that thing safely?

author: KD0RC
author_rank: Regular Contributor
timestamp: December 18, 2014, 11:45:34 pm
content: I think that the 'B' refersto a B battery which is 120 V. They were 3 or 4 inches long and maybe an inch square. They were used as the plate supply for radios. I can't imagine that they would have been able to supply much current, so probably not all that dangerous. I would not stick my tongue across it, however...
Tektronix 2245A oscilloscope - battery problem, or not. - Page 1
Forum section: electronics / testgear

author: tubeamptech
author_rank: Newbie
timestamp: December 18, 2014, 09:47:11 pm
content: Hello,I have a Tektronix 2245A oscilloscope, which I use in my repair shop. Back in 2007, I lost the signal trace, and the LED's went out. Found out the back up battery had died, I replaced it, and everything has been fine until now. Now I have the same symptom, so I put a new battery in, a Panasonic 3V, BR2/3A. I fired it up, it went through the self cal routine, and at the end it reported a possible battery failure. Does anyone have any idea's as to why that would be? The old battery, and the new battery are all measuring above 3 V. I thought I would change it, just in case the original had lost capacity. The only thing I can think is I have a connection problem somewhere, or there is a cap that's gone bad or leaky in the battery circuit.
SainSmart DDS120 Repair? - Page 1
Forum section: electronics / testgear

author: NotANewbie
author_rank: Contributor
timestamp: December 17, 2014, 06:59:38 pm
content: Despite warnings I bought this thing, and it worked fine until it stopped working.It looks like the issue is it is not isolated from the USB power ground, which is connected to the AC ground,and so is my soldering iron, so when I touched the soldering iron to some charged caps, it blew up the device.It now does not work. The computer recognizes it, the square wave test works, but the software complains.So should I just throw it in the trash can? Or possible can one replace the USB interface chip on it to fix it?
TDS-380 timing compensation failure - Page 1
Forum section: electronics / testgear

author: c4757p
author_rank: Super Contributor
timestamp: December 17, 2014, 11:00:42 pm
content: I suppose I'll probably have to ask this elsewhere, but perhaps somebody here is familiar with these scopes. I tried to run the timing compensation cal procedure on my Tek TDS-380 - when I do so, it fails the sequence without explaining what the problem was. This is, to my knowledge, a perfectly functioning scope otherwise, and the manual doesn't really give any information on what exactly this procedure evendoes, let alone what might be at fault if it fails.The technical reference manual specifies that a square wave must be provided, negative-going, 1 kHz, 200mVpp, with a rise time no longer than 10ns:This is what I fed it:The rise time iswayunder 10ns, and everything else matches the specification. There's a bit of sloppiness about 13ns after the edge - couldthatbe enough to make it decide it doesn't like the waveform? Or is there something else amiss? Could the rise betoofast? (Shouldn't be hard to whack a cap into the pulsegen if that's the case...) The rest of the waveform looks perfectly clean...

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 18, 2014, 12:05:16 am
content: That's a positive-going edge...Tim

author: c4757p
author_rank: Super Contributor
timestamp: December 18, 2014, 12:49:25 am
content: It's a negative-going waveform in that the square wave starts at ground and drops to -0.2V rather than going up to +0.2V. I'm just triggering on the rising edge (like they did)...

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 18, 2014, 12:59:11 pm
content: Ah, I see...Would guess the blip is from a capacitive reflection followed by, perhaps, a not quite ideal source match? Beats me if it's important though.Tim

author: c4757p
author_rank: Super Contributor
timestamp: December 18, 2014, 01:46:48 pm
content: Assuming rough estimates of vf=2/3 and length=1m it roughly matches with a multiple of the cable length, so that makes sense. I could probably put a tiny, SMD trimmer in there to tweak Z0 if necessary, though I think I'll search around for someone more familiar with this scope's cal routines first. Seems like it's rather picky, if that is the problem...
6671A power supply slow to current regulate - Page 1
Forum section: electronics / testgear

author: m121212
author_rank: Newbie
timestamp: December 19, 2014, 06:42:49 pm
content: Ok, weird thing! I take an Agilent (or HP or Keysight) 6671A power supply and short circuit the output terminals. I set the current limit to 2A, and the voltage limit to something, say 5V for example.When I enable the supply by pressing the Output On/Off button, I expect the supply to quickly go into current limit and regulate to 2A.What actually happens is in the attached screenshot!! Big spike (ok, output caps), but then very slow to regulate down to 2A! Screenshot attached (I hope).Maybe it has something to do with the output on/off you ask? Well, I tried leaving the output on, and using an external switch instead. Same behavior!Does it depend on the current? Same thing for 10A.By now you're thinking, maybe the supply is busted? Me too! So, I went out and bought another 6671A. Hooked it up, did the test, same BLOODY behavior!What is going on here?

author: HalfSpace
author_rank: Regular Contributor
timestamp: December 19, 2014, 10:35:11 pm
content: Hi m121212,Check the remote sensing on the back of the 6671A. It should have wire links between the output terminals and the S+ and S-. It may require remote sensing (4 wire sensing) at the point where measuring the short circuit current too get a faster response in CC mode.Here is a link to the operation guide.http://literature.cdn.keysight.com/litweb/pdf/5964-8267.pdfHalfSpace
Hioki 3256-50  - Page 1
Forum section: electronics / testgear

author: torr032
author_rank: Regular Contributor
timestamp: December 11, 2014, 07:34:20 pm
content: Here in my country locally I have a chance to buy this meter for fairly cheap, almost brand new. I can't find many infos on the net about him I know Hioki has it discontinued but it can still be ordered from taobao and it costs 4X the price of ut61e.Does anyone have this meter, I wonder is the continuity latched or unlatched and what is the burden voltage? I don't care it is not TRMS so far I really did not need this feature. I will use it mostly for electronics.

author: torr032
author_rank: Regular Contributor
timestamp: December 14, 2014, 12:01:39 am
content: Quote from: mojo-chan on December 12, 2014, 03:05:31 pmDo you have this dmm? Could you confirm is continuity latched, does it overshoot, burden voltage and so on?I know the specs but I am asking about the things that are not documented.I have a ut61e and I am looking for a dmm that would correct ut61e flaws.

author: electr_peter
author_rank: Unknown
timestamp: December 17, 2014, 05:08:34 pm
content: According to manual, Hioki 3256-50 has reasonable accuracy for hobbyist (0.5%+2 basic DC) and some nice functions, like auto hold and bar graph. I like red shutter protection for V/mA/A banana sockets. Fuses seems to be decent as well.Hioki is a good brand. If it fits your needs and budget, go for it.
Agilent DSOX 2000 Aliasing - Page 1
Forum section: electronics / testgear

author: KD0RC
author_rank: Regular Contributor
timestamp: December 17, 2014, 12:42:25 am
content: I discovered a way to get my Agilent DSOX 2022A to alias on a 10 MHz signal. I made a short video showing the effect. This only happens when the scope in in FFT mode, so I am wondering if this is a bug, or inherent in getting FFT to work.@EEVBLOG - Dave, maybe you could do an EEVBlab on whether your DSOX 3000 series scope shows the same behavior. I would also be interested in your opinion as to whether this is a bug, or a necessary artifact to create the FFT display.@W2AEW - Alan, do the TEK scopes do this as well?Here is a link to the YouTube video.http://youtu.be/JcvckkCutJUComments welcome!Len

author: MarkL
author_rank: Unknown
timestamp: December 17, 2014, 01:28:19 am
content: The Agilent scopes do random decimation to reduce the possibility of aliasing. However, it turns it off while doing FFT and some of the other math functions so that they operate normally without this added noise.It's been discussed on Agilent/Keysight's forum:http://www.keysight.com/owc_discussions/thread.jspa?messageID=108399(which then refers back to some posts here on the eevblog).

author: KD0RC
author_rank: Regular Contributor
timestamp: December 17, 2014, 02:54:34 am
content: Thanks Mark. I should have guessed that I would not be the first to find this...Len
Duspol voltmeter - Page 1
Forum section: electronics / testgear

author: markm6164
author_rank: Contributor
timestamp: December 16, 2014, 08:56:57 pm
content: I have just completed training for new Hybrid vehicles. The two required tools, required as standard, to test the system are the Fluke 1503 and the Duspol Lc volt meter. The fluke I understand but what's special about the Duspol? What's your opinion on it? All the meters they could of chosen why this? Also the li-ion high voltage battery pack can be 350v and the Duspol requires two hands to use and is bulky in the hand. I'm sure there could of been a better choice?

author: 128er
author_rank: Regular Contributor
timestamp: December 16, 2014, 10:13:59 pm
content: Hi markm6141,I don't know much about the requirements for hybrid cars. But one big difference between the two devices is the input impedance. The Fluke has 3 MOhm input impedance and there seems to be no LoZ function. Most of these Duspol type meters have fairly low input impedance. 175 kOhm for the Duspol LC. Good to reduce "ghost voltages" and to avoid false readings.That was the first thing that came to my mind. And with the switches on the Duspol you can even lower the input impedance more. You can discharge capacitors with that, or reduce ghost voltages even more.
VNA calibration: "open" standard? - Page 1
Forum section: electronics / testgear

author: dext0rb
author_rank: Contributor
timestamp: December 17, 2014, 01:22:40 am
content: Hi all,Been watching VNA videos on YouTube; hoping to own one someday.During one calibration step, the user connects an "open" standard to the VNA.What makes this more ideal than just leaving the cable end unconnected?My guess: entirely isolates the signal from the return, eliminating any capacitive coupling between tip and return.Whats the real answer? Thanks!

author: skipjackrc4
author_rank: Regular Contributor
timestamp: December 17, 2014, 02:15:01 am
content: When a connector is mated with another connector, the pin geometry changes slightly, which will alter its electrical parameters. This is especially true when using microprobes instead of cable ends.Also, the "open" standard of a cal kit will be supplied with calibration files that tell the VNA what the value of capacitance across the open is. This is necessary because it's not a perfect open--there is still some reactance there. If you were to calibrate assuming that the open was perfect, you'll get inaccurate results. The same is true with a shorted load, except the inductance is more important. Because cables change from one to another, you can't assume the value of capacitance will be constant between them unless you use a pre-measured standard.

author: Bud
author_rank: Super Contributor
timestamp: December 17, 2014, 02:28:36 am
content: Calibration standards are called so because they have known parameters. The Open standard does not eliminate fringing capacitance but rather has it well defined, and that known value is entered into the VNA so when the VNA measures some voltage during Open calibration step it knows this voltage is caused by that much of fringing capacitance.

author: dext0rb
author_rank: Contributor
timestamp: December 17, 2014, 04:10:41 pm
content: Ahhh, makes sense now. Thanks!
Charge Measurement using keithley 616 electrometer - Page 1
Forum section: electronics / testgear

author: anjan
author_rank: Newbie
timestamp: December 15, 2014, 11:57:01 pm
content: Hi,Can you tell me how to measure charge from keithley 616 electrometer ? I mean the step by step procedure and precautions to follow.ThanksAnjan
Ucurrent - Page 1
Forum section: electronics / testgear

author: billg
author_rank: Newbie
timestamp: December 16, 2014, 05:27:42 am
content: I was thinking of getting a u Current for testing both flame rectification (uA) and ionization current (nA). My question is that since half of the cycle is going to be in flame rectification mode and the other half ionization, how will it react to over range in nA setting ?

author: TriodeTiger
author_rank: Regular Contributor
timestamp: December 16, 2014, 05:43:43 am
content: If the battery voltage is increased to 5.5V (maximum) the range for nA will become ~0-2250nA, as the highest value (1mV/xyz) would be at 2.25V, because of the virtual ground (?) - so it can't go much over-range, but if it's below 2.2uA..

author: MLXXXp
author_rank: Frequent Contributor
timestamp: December 16, 2014, 06:50:17 pm
content: If you go out of range, the output voltage will pin at close to + or - half the supply voltage.If you're wondering about how safe it is to go over-range, here's a post with some (very conservative) calculations I did a while back:https://www.eevblog.com/forum/crowd-funded-projects/current-gold-on-kickstarter/msg375819/#msg375819If the uCurrent is always on, or you add some protection diodes for power off, the safe ranges increase:https://www.eevblog.com/forum/crowd-funded-projects/current-gold-on-kickstarter/msg376311/#msg376311The protection diodes, and modifications that I made to shift the virtual ground, which may be useful for your situation, are described here:https://www.eevblog.com/forum/crowd-funded-projects/current-gold-on-kickstarter/msg448208/#msg448208

author: billg
author_rank: Newbie
timestamp: December 16, 2014, 08:08:30 pm
content: Thanks for the replies, MLXXXp this is just the what I needed:)
Rigol wmf file format - Page 1
Forum section: electronics / testgear

author: aroby
author_rank: Regular Contributor
timestamp: December 15, 2014, 10:14:53 pm
content: I'm trying to get the wfm_viewer application (http://meteleskublesku.cz/wfm_view/) working with my DS2072A. It kind of works, but complains that the trigger mode is not recognized. I have also tried the Python code (https://github.com/mabl/pyRigolWFM/blob/master/wfmutil.py) that was sourced from the parser for wfm_viewer, but that can't process my file - seems that the header on the file has changed signficantly.Has anyone come across documentation for the wfm format Rigol are using or have a working parser for the DS2072A?Anthony
Maynuo M9710 and RS232 cable for PC connection - Page 1
Forum section: electronics / testgear

author: MarTim66
author_rank: Newbie
timestamp: December 15, 2014, 02:52:47 pm
content: Hi there!Today I get Maynuo M9710 tester. I need this for mobile power banks and USB chargers.The device didn't come with RS232 cable to the computer. I need it with the USB plug. So, what do I need to know that I can buy the right cable? I don't have time now to order Maynuo's own (expensive) cable.Does it work with any RS232 cable with the USB male plug? Can the device be damaged because the wrong cable?I'm a bit noobie in these hardware issues.

author: mij59
author_rank: Frequent Contributor
timestamp: December 15, 2014, 03:43:17 pm
content: Hi,The Maynuo M9710 has no RS232 input, and the in and output of the interface cable are isolated.You will need a usb to RS232 converter and e.g. an Adum1201 isolator.

author: HighVoltage
author_rank: Super Contributor
timestamp: December 15, 2014, 05:31:33 pm
content: You should get the original cable that is offered for the instrument.It is low cost and works very well.
Hantek 6022BE red light blinking - Page 1
Forum section: electronics / testgear

author: edcree
author_rank: Newbie
timestamp: December 15, 2014, 10:43:32 am
content: Hi, I'm new to this forum and this is my first post. Have just bought a Hantek 6022BE and it all seems to be working OK on Windows XP. I noticed that there is a red light next to the probe connectors, that keeps blinking. Is this normal? There is no mention of this light in the manual. Not sure if this topic has been raised before - Thanks in advance for any information. Cheers
DS1054Z warrenty - Page 1
Forum section: electronics / testgear

author: electros6
author_rank: Regular Contributor
timestamp: December 15, 2014, 05:54:18 am
content: Hi guys ,I recently purchase rigol DS1054Z and it comes with 3 years warranty. I like to hack it to unlock all features. does the warranty covers even after the hack.

author: nanofrog
author_rank: Super Contributor
timestamp: December 15, 2014, 06:12:53 am
content: As long as it's able to communicate over USB and execute the right SCPI command (:SYSTem:OPTion:UNINSTall), it the software hacks can be undone prior to sending it in for warranty service.
TEK 2465A/2455A/2445A ULTRA HQ PDF USER MANUAL - Page 1
Forum section: electronics / testgear

author: macbreak
author_rank: Contributor
timestamp: December 15, 2014, 02:05:14 am
content: I bought this manual ages ago, so I thought I'd share this with you. I almostguaranteeyou that you won't find a better quality scan of the user guide (I searched in all the nooks and crannies on the net for weeks, and only found rubbish scans), bar paying for it:https://mega.co.nz/#!s9FBnLgR!k2uFITu9DY5ICHjstCyshxYQOiPOoP-oY9791Uc0D70Please feel free to share around and mirror it - the net needs a good copyEnjoy
DP811A ( DP800 ) SCPI Command Calibration for PC - Page 1
Forum section: electronics / testgear

author: cidak
author_rank: Unknown
timestamp: October 31, 2014, 10:45:44 pm
content: Hi everyone, I'm the owner of DP811A, I installed the v1.11 firmware.I made the calibration of the V-DAC and the I-DAC output voltages and now all wrong.I tried for three days to redo the settings, to no avail. Then I read here on the forums that the 11.1 have a bug.Now I have an old iron box unusable paid 750 Euros.Someone can 'help me to solve this problem?I contacted RIGOL EU Engineer Mr Thomas told me that I should not touch the calibration and now so I have no warranty and I have to send them by paying the repair.To me this does not seem fair, I did not do the problem, but they did their damage with a firmware bug.Someone SCPI commands for calibration, or any other solution to seat the power supply?THANKS!

author: TooOldForThis
author_rank: Regular Contributor
timestamp: December 02, 2014, 02:33:36 am
content: Hello cidak,Use the SCPI calibration instructions postedHereThey should work on the DP811A too. But the DP811A has different calibration points. Use the cal points in the document I attached.

author: TooOldForThis
author_rank: Regular Contributor
timestamp: December 02, 2014, 02:45:26 am
content: The DP811A can output 10.5Amps. So unless you have a real brute for a DMM, you'll have to measure the upper current ranges by measuring the voltage across a low impedance power resister attached between the + and - terminals.

author: cidak
author_rank: Unknown
timestamp: December 14, 2014, 03:50:49 pm
content: Thank you very much for providing information on how to calibratetheDP811APower Supplies.I for one appreciate this very much, and I'm sure everyone else here does also.
Red Pitaya scope/sig gen/spec analyzer Who's got one? - Page 1
Forum section: electronics / testgear

author: SNGLinks
author_rank: Regular Contributor
timestamp: November 26, 2014, 04:13:58 pm
content: http://redpitaya.com/?skip_intro=noStocked by RS.Who's got one and what do people think of it?Here is the spec:https://www.dropbox.com/s/b2pxkwj1ljzyw71/Red_Pitaya_HW_Specs_V1.1.1.pdfAshley

author: zimmerman255
author_rank: Newbie
timestamp: December 15, 2014, 06:31:38 pm
content: Hey, i have one.I really like it! I bought it because i'm making prototypes for my startup and i have small lab. It was much more cheaper for me to get all the instruments(oscilloscope, spectrum analizer, signal generator) seperatley. Im using it to debug my circuits.My first contact with red Pitaya was in school. We use it at our practical work!There are GPIOs, fast analog in and outputs available. I find it beneficial because i can modify the code and create my own custom apps and when new instruments come up, i can just install them for free on my Red Pitaya. I heard that LCR meter is quite good.I think it's a great platform for people that don't need ultra wide bandwith oscilloscopes.
Rigol DS1054Z - Function Generator? FFT? - Page 1
Forum section: electronics / testgear

author: K3mHtH
author_rank: Regular Contributor
timestamp: December 13, 2014, 06:25:16 am
content: Hey guys,I'm looking at getting a digital 'scope, and looking into the Rigol DS1054Z because it meets my budget. I'm finding the Rigol site a bit scant on details and the manual to be pretty useless. I'm wondering if someone can tell me, does the DS1054Z include the function generator and FFT view? I'd love for that feature, I repair a lot of guitar amps and it would be great to run a sine wave or white-noise through the amp using only 1 piece of test equipment.I also know the DS1054Z can be easily hacked into an DS1104Z, would that model include those features?Thanks guys,

author: extide
author_rank: Regular Contributor
timestamp: December 13, 2014, 04:45:38 pm
content: Not sure about fft, but I think all models include it. Function gen is only on -s models, the cheapest of which is the 1074z-s. You cannot hack-enable the function gen.

author: Creep
author_rank: Regular Contributor
timestamp: December 13, 2014, 07:40:16 pm
content: I can confirm that the DS1054Z has FFT. And like mentioned earlier, it does not have a signal generator.

author: K3mHtH
author_rank: Regular Contributor
timestamp: December 14, 2014, 06:55:19 am
content: Thanks for the clarification guys, it's a shame about the function generator.. but I'm probably asking for too much at that price.

author: kripton2035
author_rank: Super Contributor
timestamp: December 14, 2014, 07:58:55 am
content: it's not that difficult to build a small sinus generator for audio, and also a white noise generatoryou can get xr2206 chinese copies to do the sinus for some $then get the ds1054z without the function generator, the tool in itself deserves it
Anything better than Tenma 72-7745 for ~USD100 ? - Page 1
Forum section: electronics / testgear

author: pfm
author_rank: Regular Contributor
timestamp: December 16, 2014, 07:23:13 pm
content: Have narrowed it down to a Tenma 72-7745. My primary requirements are -TrueRMSAC Current greater than 2ALogging (rs232, usb, blutooth, .. anything)around USD100.http://www.farnell.com/datasheets/1692905.pdfHow do the Instek GDM-397/461 compare to this ? Does one have better accuracy and build quality than the other ? Or does one have better data logging/viewing capabilities than the other ?http://www.gwinstek.com/en/product/productdetail.aspx?pid=39&mid=80&id=204Any other worth considering ? If its a good meter then it doesn't have to be "handheld". I am ok with any other form factor also.Please advise.Thanks!

author: retiredcaps
author_rank: Super Contributor
timestamp: December 16, 2014, 08:51:39 pm
content: Quote from: pfm on December 16, 2014, 07:23:13 pmTenma is a rebranded Uni-T (edit: UT60E).http://uni-trend.com/UT60E.htmlQuoteAgain another rebranded Uni-T UT61E. There is lots of discussion and videos about this meter.If you are going to buy Uni-T, you will likely get better prices on ebay direct from China based sellers vs the big name distributors.

author: retiredcaps
author_rank: Super Contributor
timestamp: December 16, 2014, 09:51:50 pm
content: Todd did a review of the Tenma 72-7745 (UT60E)

author: Lightages
author_rank: Unknown
timestamp: December 16, 2014, 10:30:57 pm
content: Get the Uni-T UT61E if you want a better deal than the Tenma. It can be had for $55 and lower on ebay shipped to your door. If you can spend $120, then consider a Uni-T UT71B. It has more features and also does TRMS AC+DC. The UT61E only does TRMS AC.Neither of these, nor your selections, have very good input protection but are fine for electronics and bench use.If you want another option, there is the UT139C which does TRMS AC and is built safely, but does not have logging. Then you can buy a Digitek DT4000ZC that has logging, but is not built with very good input protection and does not do TRMS.http://www.ebay.com/itm/Uni-T-UT139C-True-RMS-Digital-Multimeter-with-Temperature-NCV-Backlight-/171213085325http://www.ebay.com/itm/Digitek-DT-4000ZC-TekPower-TP4000ZC-Data-Logging-Multimeter-with-Temperature-/200912705694Both of these for well under $100 delivered to your door. The seller is a member here who is very well respected. His name here is iloveelectronics.If you want a one, do it all, safe and accurate meter with logging, TRMS AC+DC too, then you need to spend quite a bit more.If you can spend $200