hybridfree/eevblog-posts huggingface dataset:
Uni Trend UT-70D multimeter calibration - Page 1
Forum section: electronics / testgear

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 12, 2014, 02:27:32 pm
content: Hello Guys, I managed to make my multimeter working again.!https://www.eevblog.com/forum/testgear/uni-trend-ut70d-dead-(or-similar)/msg455510/#msg455510Does anyone know how to perform a calibration of this DMM ? I saw a way how to adjust UT-71D but found nothing about UT-70D.I may use a proper equipment for that (meaning standard and calibrated bench multimeter)....Thanks in advance

author: Lightages
author_rank: Unknown
timestamp: July 12, 2014, 11:11:58 pm
content: Try emailing Uni-Trend. They responded to me.

author: Warhawk
author_rank: Frequent Contributor
timestamp: July 13, 2014, 06:24:29 pm
content: Quote from: Lightages on July 12, 2014, 11:11:58 pmDid you use "info@uni-trend.com" ?Few years ago I tried to reach them and got this:"You feed back in the electric capacity files position stochasticdemonstration's question, does not have the problem which the software canrevise, the UT70 software is transmits the function, beyond controlprecision and demonstration.In avonmeter's some grades of positions, demonstrated stochastically thedigit does not affect the function survey, is normal, including fluke sometables, for instance is the stochastic demonstration digit or demonstratesol in the electric capacity files position, this is the field permission,the UT70D customer feeds back the electric capacity files stochasticdemonstration question is normal, informs the customer not to need to worry."But anyway, it is worth the try.

author: Lightages
author_rank: Unknown
timestamp: July 14, 2014, 01:50:10 am
content: qadb003@uni-trend.com.cn is who I got a response from. Who did I send the original email to? info@uni-trend.com

author: Warhawk
author_rank: Frequent Contributor
timestamp: August 18, 2014, 11:11:49 am
content: Quote from: Lightages on July 14, 2014, 01:50:10 amHowever with no success. The mail does not exist any more and info@uni-trend.com is not responsive.

author: Wytnucls
author_rank: Super Contributor
timestamp: August 18, 2014, 11:44:02 am
content: Try the one in Dongguan:
Racal-Dana 1992 QuickFix Stuck Key - Page 1
Forum section: electronics / testgear

author: rastro
author_rank: Frequent Contributor
timestamp: August 04, 2014, 03:23:01 pm
content: This is a quick fix NO-Solder solution for those stuck/mushy keys on the Racal counters.I saw some great forum threads on resolving marginal/broken keys on the Racal counters.However I could not go through the process of replacing (soldering) all those keys.Here's what worked for me.OVERVIEW:Use a Tack-Switch'S flexible metal switch contact as the main component to replace the failed "rubber" contact.Part of the Racal switch base needs to be insulated with tape.The Racal key/plunger needs to be extended to make contact with the replacement "flex tack switch contact".I used a pellet of instaMorph* to extend the key plunger because it was handy and had the right dimensions.* Any similar size bead will probably work.PROCEDURE:01) Disassemble a tack switch - usually cut 4 plastic wields with razor. Use only the flex metal switch contact.02) Remove problem key cap & plunger by carefully pulling out with serrated pliers & needle nose.03) Clean out any rubber debris from the Racal switch base.04) Use a thin piece of (thin)tape to cover bottom 20%-30% of switch base - tedious part.05) Remove all of old rubber contact from Racal key plunger.06) Set Racal unit on its back so replacement components will drop into the key housing.07) Place "flex tack switch contact" with "dome" up (outer ridge sits on bottom of housing & tape)...08) Place istaMorph pellet (or comparable part) on top of tack switch contact.09) Slowly install key plunge being sure to center pellet before snapping into place.10) Reinstall key-cap.TROUBLESHOOTING:A) Switch always on:- Tape coverage on the bottom contact of key housing allowing bottom ridge of flex tack switch to contact bottom side housing contact.B) Switch clicks but does not activate.- Tape covering too much of center contact.C) Switch not clicking or activating- "flex tack switch contact" installed upside down.- Dimensions of pellet (extension) not providing adequate contact.RegardsRastro

author: saturation
author_rank: Super Contributor
timestamp: August 17, 2014, 11:05:11 am
content: Thanks, can't hurt to try another method beyond a full overhaul.

author: rastro
author_rank: Frequent Contributor
timestamp: August 17, 2014, 12:43:43 pm
content: Hello saturation,I found the modified key's engage ~95% of the time. It's not perfect but will get you past the problem keys without a complete tear-down. I originally had to do this mod because I couldn't get a recently acquired counter to run due to a key that was stuck in on position. The mod got me to the point where I could functionally check the rest of the counter.I think some improvements could be explored with the plunger. Maybe a softer or more flexible material pressing against the metal flex plate???Anyway good luck - let me know how it works out.
Rigol oscilloscope remote control using NI-Visa - Page 1
Forum section: electronics / testgear

author: martinLink
author_rank: Newbie
timestamp: August 16, 2014, 05:38:54 pm
content: Recently I was developing code for Rigol DS1074Z oscilloscope remote control using National Instruments Visa from C program level. I noticed that it is not easy to find information how to setup a C/C++ project and link all necessary library files.That is why I have prepared this shorttutorial how to use NI-Visa in 5 simple steps:http://linkbone.com/rigol-oscilloscope-remote-control-visa-scpi/I hope this tutorial will be useful for those who are developing test automation setups. It includes example how to enable Rigol pass/fail signal test shown on picture below via remote SCPI commands.If something is not clear or requires additional explanation please let me know. All comments are welcome

author: Melt-O-Tronic
author_rank: Frequent Contributor
timestamp: August 17, 2014, 04:43:12 pm
content: Thank you for that!
MOVED: A few left: HP 6216A (0-25V) supplies on eBay - Page 1
Forum section: electronics / testgear

author: GeoffS
author_rank: Unknown
timestamp: August 17, 2014, 07:16:25 am
content: This topic has been moved toBuy/Sell/Wanted.https://www.eevblog.com/forum/index.php?topic=35285.0
Rigol DS2072 RS232 Event Table - Page 1
Forum section: electronics / testgear

author: Circlotron
author_rank: Super Contributor
timestamp: August 17, 2014, 03:01:22 am
content: Hi all. Just trying to track down a problem with my chip programmer. Got the scope RS232 Event Table showing and when I monitor about 1K bytes of data, instead of filling up the event table it only uses the top 3 or 4 lines in what looks almost like a first in first out basis. I want it to fill up and then go through line by line and compare the recorded bytes with what they should be. What am I doing wrong?

author: Circlotron
author_rank: Super Contributor
timestamp: August 17, 2014, 03:30:51 am
content: Okay, think I've got it. Set to 2 sec/cm and longest memory depth, record the data burst in one screen, then stretch it out so that one or two bytes fill the screen then turn on the event table and Bob's your uncle.

author: Mark_O
author_rank: Frequent Contributor
timestamp: August 17, 2014, 03:54:53 am
content: Quote from: Circlotron on August 17, 2014, 03:30:51 amOK, that's all well and good. But who's my aunt?
DS2072 screen pointer R1 ? - Page 1
Forum section: electronics / testgear

author: Circlotron
author_rank: Super Contributor
timestamp: August 16, 2014, 05:41:42 am
content: Was messing around with scope the other day and later on I noticed it had this R1 pointer on the LHS. What is that so I can turn it off again? See pic.

author: JDubU
author_rank: Frequent Contributor
timestamp: August 16, 2014, 05:49:01 am
content: Press the "Ref" button (located between the two vertical scale knobs).Press the "Channel" button (top button of the right hand vertical screen menu).Uncheck "Ref1" in pop up menu.

author: Circlotron
author_rank: Super Contributor
timestamp: August 17, 2014, 02:55:21 am
content: So easy!Thanks!
Hantek DSO8000E and 1000E series-IP51-Hacking-200MHz free   - Page 1
Forum section: electronics / testgear

author: henry
author_rank: Newbie
timestamp: August 12, 2014, 09:39:30 am
content: My FLUKE199 damaged last month. I got a new handheld oscilloscope from China. Model is DSO8072E.It looks very nice. I opened it today. I want to share some photos.If possible, I want it hack it to 200MHz.

author: limpid
author_rank: Contributor
timestamp: August 12, 2014, 11:54:12 pm
content: it is interesting, but I would like to know what different between this and Hantek another 1000B series?

author: tinhead
author_rank: Super Contributor
timestamp: August 13, 2014, 09:06:51 am
content: hmm

author: commongrounder
author_rank: Frequent Contributor
timestamp: August 13, 2014, 12:55:24 pm
content: The case looks much sturdier than the regular 1000 series scopes, plus the IP51 rating gives good dust protection and some moisture protection. I think they would do well to release a version of this with isolated inputs. That would put it more in line with a Fluke scopemeter. I also noticed in the photos that the multimeter section has real high current interruption fuses, instead of the cop-out 20mm glass fuses. I wonder if this series has a true electrical cat. rating. Interesting.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: August 15, 2014, 01:51:24 pm
content: The color scheme makes me think of an old Linksys wireless router. Really really surprised to see those large HRC fuses in there. A very pleasant surprise.

author: tinhead
author_rank: Super Contributor
timestamp: August 16, 2014, 11:00:33 am
content: i have no fucking idea who "Henry" is, but this are all my pictures, posted already herehttps://www.eevblog.com/forum/testgear/hantek-dso1000e-dso8000e-handhelds-teardown-and-ip51-test/msg475863/#msg475863with pictures on my onedrivehttps://onedrive.live.com/?cid=c4ddf72e6eea3826&id=C4DDF72E6EEA3826%21168#cid=C4DDF72E6EEA3826&id=C4DDF72E6EEA3826%21580The only thing "Henry" did was to photoshop (add) two extra BNC s'I did send him PN, but no answer. I have no idea if he is simply an idiot, a kid or'small sized'Hantek dealer/employee.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: August 16, 2014, 11:25:54 am
content: Probably a spammer or "spammer" trying to build reputation. I'm curious though, where are those BNCs added? I don't see that.

author: Bored@Work
author_rank: Super Contributor
timestamp: August 16, 2014, 11:27:29 am
content: Quote from: tinhead on August 16, 2014, 11:00:33 amThen lets ask a moderator to delete the posting and probably "henry", too.

author: Andy Watson
author_rank: Super Contributor
timestamp: August 16, 2014, 11:35:33 am
content: Quote from: nitro2k01 on August 16, 2014, 11:25:54 amFourth picture - the four inputs in a line. The middle two don't have shadows!

author: GeoffS
author_rank: Unknown
timestamp: August 16, 2014, 01:12:45 pm
content: Despite his flag saying he's from the USA, 'henry' is from China.Interestingly, he's been registered on the forum for two and a half years, a slow spammer.
HP 8568A Fan Noise - Page 1
Forum section: electronics / testgear

author: George_Race
author_rank: Regular Contributor
timestamp: August 15, 2014, 06:27:51 pm
content: Does anyone have any suggestions for replacement of the two 110 VAC fans that are in the 8568A?They need to be at least 50 CFM, that is what the original noisy one are.A higher CFM probably would not be a bad idea, but I am looking for quiet as possible.George
Fluke 183 display needed - Page 1
Forum section: electronics / testgear

author: torr032
author_rank: Regular Contributor
timestamp: July 13, 2014, 01:00:25 am
content: Display on my Fluke 183 is completely cracked, does anyone maybe have one spare or know where I could find it?Fluke 183 pics:http://postimg.org/image/lv1pr0nfd/

author: mzacharias
author_rank: Frequent Contributor
timestamp: July 13, 2014, 01:43:59 am
content: Well, if you cannot find the Fluke part, the display from a Tektronix TX-1 would be the same part... The Tektronix TX-1 and TX-3 models were re-branded as the Fluke 183 and 185 models.

author: WVL_KsZeN
author_rank: Regular Contributor
timestamp: July 13, 2014, 08:18:20 am
content: I've got a display from a 185 lying around (the 185 itself is borked, it gives nocal when booting). It's yours if you want it for the shipping cost.

author: torr032
author_rank: Regular Contributor
timestamp: July 13, 2014, 04:47:55 pm
content: Yeah I know its Tektronix TX-1, but I am unable to find any.WVL_KsZeN thanks for your help, I sent you a message.

author: WVL_KsZeN
author_rank: Regular Contributor
timestamp: July 15, 2014, 08:00:37 pm
content: A new screen is on it's way! Please post a picture of your fixed meter :-)

author: torr032
author_rank: Regular Contributor
timestamp: July 16, 2014, 03:56:57 pm
content: Thank you very much my friend, I can't believe in this wack world there are still ppl like youSure I will post a pics here.

author: torr032
author_rank: Regular Contributor
timestamp: August 15, 2014, 12:08:41 am
content: Display came today, thank you very much Werner for your gesture I really appreciate that. When I find the instrument I will post the pics, he is now mysteriously gone

author: WVL_KsZeN
author_rank: Regular Contributor
timestamp: August 15, 2014, 07:05:58 am
content: Can't believe it almost took a month to arrive

author: torr032
author_rank: Regular Contributor
timestamp: August 15, 2014, 10:40:12 am
content: Quote from: WVL_KsZeN on August 15, 2014, 07:05:58 amIt happens from time to time, sometimes even two months can passed.
Fluke 332b score - Page 1
Forum section: electronics / testgear

author: PaulAm
author_rank: Frequent Contributor
timestamp: August 15, 2014, 02:30:15 am
content: I've been looking on and off for a year or so for a deal on a Fluke voltage standard. The other week I ran across a BIN on ebay with a make offer on a Fluke 332b that was advertised as "not working, for parts". The description said that sometimes it would output a voltage and then go to zero. What the heck, I gave the guy a low ball offer and it was accepted. Showed up the other day and, indeed, it produced output at some settings and then nothing after turning up the voltage. A not so close inspection showed the Voltage Limit control turned almost all of the way counterclockwise, so it would trip at a very low output. Disabling it by turning the vernier clockwise and setting the limit switch to 1000V as detailed in the manual resulted in a fully functional 332b. Well, almost fully functional. Two of the decimal point lamps are burned out.Gotta love sellers who don't know how to operate what they're selling.Now I have to get the dang thing verified or calibrated. The only meter I have that reads to microvolt resolution is an hp 3456a and I know that one is off.
Is the probe or the scope that has the impedance? - Page 1
Forum section: electronics / testgear

author: asgard20032
author_rank: Regular Contributor
timestamp: August 11, 2014, 04:34:16 pm
content: When we take a 1M probe, does this mean the probe is made for a scope at 1M, or does it mean the probe has 1M?In other word, is it the probe+cable or the scope that do all the impedance?

author: c4757p
author_rank: Super Contributor
timestamp: August 11, 2014, 04:53:28 pm
content: Typical oscilloscopes have an input impedance of 1 megohm in parallel with 10-22pF of capacitance - that's in the scope. Whether the probealsohas this input impedance depends on the probe. Is there a specific one you're asking about?

author: w2aew
author_rank: Super Contributor
timestamp: August 11, 2014, 04:57:02 pm
content: Quote from: asgard20032 on August 11, 2014, 04:34:16 pmMost sub 300-500MHz scopes have a 1Mohm input impedance. The 300-500MHz BW and higher BW usually will have a switchable 50 ohm termination as well.10x passive probes are designed to work with the 1Mohm input impedance of the scope. The probe has a 9Mohm series input resistor, making the total DC impedance at the probe input equal to 10Mohm. If the probe is switchable to 1x, then the input impedance at the probe tip will basically be the scope's 1Mohm impedance (but with a sizable shunt capacitance - 100pF or more).When you start looking at active probes, then they will be specified with their own input impedance.

author: jimmc
author_rank: Frequent Contributor
timestamp: August 12, 2014, 08:58:42 pm
content: You might like to read this primer on 'scope probes from Tektronixdocuments.rs-components.com/EITC/UK/electronics/abc.pdf.In particular Fig 3-6 on page 24 shows how badly a 10M probe can load a circuit at high frequencies, it's not just the capacitive reactance that's the problem.Jim

author: Sailor
author_rank: Regular Contributor
timestamp: August 14, 2014, 09:21:37 am
content: There was a *really* good article in Silicon Chip on scope probes. October 2009, page 16-23. "The Secret World of Oscilloscope Probes", by Doug Ford. Very much worth hunting down and reading.

author: Mechatrommer
author_rank: Super Contributor
timestamp: August 14, 2014, 10:44:05 am
content: Quote from: asgard20032 on August 11, 2014, 04:34:16 pmwhat do you care? you should only care whats the voltage limit a probe+scope can take, ie its attenuation factor. the rest is taken care by the little trimpot adjustment in the probe body aka "frequency respond compensation". with 1/10X probe you'll have 10Mohm impedance combined, with 1/100X probe you'll have 100Mohm impedance combine, given the dso input is 1Mohm... so what?

author: HighVoltage
author_rank: Super Contributor
timestamp: August 14, 2014, 06:42:29 pm
content: Quote from: jimmc on August 12, 2014, 08:58:42 pmWhat a nice document.Thank you!

author: Unknown
author_rank: Unknown
timestamp: August 15, 2014, 12:44:31 am
content: Quote from: Sailor on August 14, 2014, 09:21:37 amIt's available on his website -link to page.
Extech EX330 low battery indication - Page 1
Forum section: electronics / testgear

author: davidxy01
author_rank: Newbie
timestamp: August 14, 2014, 07:38:06 pm
content: Hi all!I thought I quickly share a problem I run into today. Yesterday my Extech DMM run low on battery and the low battery icon came on. I didn't have new ones to hand at this point, so I finnished some basic continuity checking with the low battery, shouldn't be a big deal. Today I switched out the old batteries because it didn't came on anymore and I thought the batteries are too low now. However after replacing the batteries still no change, the only thing working was the Non-Contact Voltage Detector.So I opened the thing and found a very neat modification which has taken place on the wipers of the rotary knob (see attachments). Looks like the small wiper clamp isn't able to handle the current drawn from the battery during low battery operation and molded itself into the plastic casing. Luckily it molded deep enough to cut the connection to the battery.Yeah they state in the manual to replace the batteries when the indication appear, however it shouldn't destroy itself as a "EEVblog DMM Shootout Winner" if you don't react immediately.btw: I already fixed it with some epoxy to fill up the holes and reinserted the wiper clamp.

author: retiredcaps
author_rank: Super Contributor
timestamp: August 14, 2014, 07:48:12 pm
content: Hmm, interesting. Thanks for sharing that tidbit with us.PS. I often put very low/near dead 9V batteries into my Fluke 70 series (2000 hour life on a 9V) as they can suck out a bit more juice and maintain accurate readings.

author: SeanB
author_rank: Super Contributor
timestamp: August 14, 2014, 07:50:26 pm
content: Wonder just how much current you have to draw to get the plastic to melt. Might be a good thing to add some lubricant to ensure a better contact and keep the contact surfaces clean and non-oxidised.
Rigol oscilloscope - Page 1
Forum section: electronics / testgear

author: Electronicreator
author_rank: Newbie
timestamp: August 13, 2014, 07:46:55 pm
content: Hello guys, I wanted to know if somebody have used the Rigol MSO11047Z and if it is any good.I also wanted to know your advices for a good and cheap(<1500$) mixed signal oscilloscope.Do you think that for microcontroller/FPGA project that involves an audio DAC, 100mhz of bandwidth will be enough for the oscilloscope?

author: DanielS
author_rank: Frequent Contributor
timestamp: August 13, 2014, 08:55:22 pm
content: For the analog part of audio stuff, even 1MHz would be enough but you might want to look at equipment with higher vertical resolution if you want to look at fine variations in output signal. For the digital part, that would depend on how fast your digital stuff is going to be.If you do eight-channel, 24bits, 192kbps, you will have a serial bit rate of about 40Mbps. You need two edges per cycle so in the worst case where the bitstream is 101010101... you get a 20MHz fundamental. You ideally want at least the first three harmonics to get reasonably sharp edges and that brings you to 100MHz.If you are going to use external DDR memory running at 100MHz, then a 100MHz scope is going to be too slow to see clear signals since a large chunk of the signal's energy content will be beyond 200MHz. It will make edges look awfully sloppy assuming you can still see them at all.

author: Electronicreator
author_rank: Newbie
timestamp: August 13, 2014, 10:17:30 pm
content: Ok, I will keep that in mind
DS4000 series hack - Page 1
Forum section: electronics / testgear

author: cksa
author_rank: Regular Contributor
timestamp: August 13, 2014, 10:39:24 am
content: I wonder if the DS4012 can be "upgraded" to a DS4052? O0

author: Gunb
author_rank: Regular Contributor
timestamp: August 13, 2014, 11:44:55 am
content: already done month ago.sleep well
Sencore SG165 stereo analyzer questions - Page 1
Forum section: electronics / testgear

author: xwarp
author_rank: Frequent Contributor
timestamp: August 13, 2014, 02:23:45 am
content: I think I am missing something or thinking too hard.....or maybe I'm getting old and don't remember shit...In any case, I am working on this Sencore Stereo analyzer.The particular area of concern at the moment involves the MPX board, specifically, the 19khz multivibrator section.Attached is a portion of the schematic and shots of the scope at various points, and a screen shot of what the service manual shows for those points.I can't attest to the correctness of the manual.The top waveform of the scope screen shot is 38khz that is being coupled into the 19khz via c213 and c214.The bottom waveform is at various points.The first scope picture is at tp13 which is supposed to be a 19khz 12v p-p waveform.The second is at the node of r27 and r28.The third is at the node of r31 and r32, which is supposed to be a 19khz 1.1v p-p sine wave.Am I missing something here?I've changed out the 20uf caps as the old were out of tolerance and who knows what the ESR was on them as I didn't even bother to measure that.
thermal camera reviews at CITA forums - Page 1
Forum section: electronics / testgear

author: ixfd64
author_rank: Frequent Contributor
timestamp: August 12, 2014, 10:59:53 pm
content: Has anyone seen this forum?http://cita.org.au/forumdisplay.php?f=16It's mainly for people in the thermography industry, but there are a lot of useful reviews for various brands of thermal cameras.

author: Fraser
author_rank: Super Contributor
timestamp: August 12, 2014, 11:52:19 pm
content: An interesting site. ThanksIt is good to see side by side comparisons of the cameras images and the effects of enhancements such as the Testo Super Resolution option.Aurora
Testo Thermal Camera Hidden Menu access ? - Page 1
Forum section: electronics / testgear

author: Fraser
author_rank: Super Contributor
timestamp: August 12, 2014, 01:38:11 am
content: Does anyone know how to access the hidden menu's on a 800 series Testo thermal camera please ?My specific model is the 880-1 built in 2009. Response by Personal Message if preferred.The camera is also sold under the Electrophysics (Sofridar) brand with the same model number.Any other model 'secrets' also welcomedMany ThanksAurora

author: ixfd64
author_rank: Frequent Contributor
timestamp: August 12, 2014, 08:29:48 pm
content: I don't own a Testo camera, but I'm also interested in what could come out of this.
BNC DC blocking Cap - Page 1
Forum section: electronics / testgear

author: luky315
author_rank: Regular Contributor
timestamp: August 12, 2014, 11:13:05 am
content: I am looking for a decent DC blocking cap for noise measurements. The Pomona 5297 with a 1nF blocking cap is ok for measurements >30MHz, but I am also interested in the lower range so ~100nF would be great. But I can't find something in this range. Have I overlooked something?

author: ovnr
author_rank: Frequent Contributor
timestamp: August 12, 2014, 04:01:38 pm
content: Well, make your own then? If you only use it for your <30 MHz needs, it doesn't need to be overly special.Grab one of the ridiculously overpricedPomona BNC boxesand solder a high-quality cap in between the center pins. Poof, you're done.Part of me does wonder why you're not just enabling AC coupling mode on your scope or whatever, though.
VC99 handheld multimeter schematic - Page 1
Forum section: electronics / testgear

author: akis
author_rank: Frequent Contributor
timestamp: August 12, 2014, 07:09:04 pm
content: I noticed my handheld multimeter is a bit off when it comes to DC voltage measurement. I have opened it and it has a dozen trimmers. I do not know which one is responsible for the DC voltage measurement, so I am not touching anything. Doing a search on the net has not produced a schematic or a "calibration procedure".I need the schematic or ideas how to fix it. I do not want to hear "throw this crap out and buy a proper multimeter".

author: omgfire
author_rank: Regular Contributor
timestamp: August 13, 2014, 05:33:27 am
content: http://www.ic-fortune.com/upload/Download/FS9922-DMM4-DS-11_EN_63291.pdf

author: johansen
author_rank: Super Contributor
timestamp: August 13, 2014, 07:23:16 am
content: i should know this off the top of my head, because i just did this with mine. i think its either number 4,5 or 6, i can't recall, i do recall it was a rather wide range, it took a bit of effort to get it within a millivolt from my 1.0186volt weston cell.

author: akis
author_rank: Frequent Contributor
timestamp: August 13, 2014, 07:32:32 am
content: Thanks for the schematic and info, will read through the PDF now to see which trimmer it is.Edit: looking at the suggested schematic it appears VR1 adjusts the ref voltage so I used just that to set the true DC voltage. Hopefully it has not affected anything else.
HP 3478A Noise on Output - Page 1
Forum section: electronics / testgear

author: schopi68
author_rank: Regular Contributor
timestamp: August 11, 2014, 09:34:57 am
content: While doing some measurements on a 20 mV 10 MHz sine signal with an Oscilloscope in parallel to my HP 3478A i saw that the scope triggered out of sync to the sine signal sporadically.I could isolate this to my hp 3478A. The Multimeter seems to send some noise out of it's measurement port (i think it was around 10-20 mVpp). It looks like typical digital noise produced by internal digital circuits/clocks.The noise seems to be independed of the input mode selected.I am wondering if this is normal behaviour for 3478A or is it worth to do some more investigation on this?Can somebody else observe this too?(All the measurements done with this 3478A are completely fine and in spec).

author: David Hess
author_rank: Super Contributor
timestamp: August 11, 2014, 07:44:35 pm
content: I tried to measure this but most of what I saw was 60 Hz interference. It is not unusual for digital multimeters to affect the circuit they are measuring via charge pumping.I would not rule out some kind of ground loop problem. The multimeter's inputs are galvanically isolated however there is still capacitive coupling.

author: alexwhittemore
author_rank: Frequent Contributor
timestamp: August 11, 2014, 11:36:59 pm
content: I've definitely measured before what I thought might be noise coming out of the meter input, but found that it was external interference coming in through unshielded sections of my probing setup. In particular, I was using a BNC to coax connector on the meter to a BNC-probe tip adapter, but the noise was coupling in on banana power wires connected elsewhere.

author: schopi68
author_rank: Regular Contributor
timestamp: August 12, 2014, 07:54:56 am
content: Yesterday i did some more measuring on this observation. In my setup i can get a very clear signal. This is the screenshot i've made:I am very shure that this is coming out of the input. My observations are:The signal goes away when the unit is powered offthe signal goes away when switched from the front to the rear connector (then it can be measured on the rear side)The signal does not change while switching through the meter ranges or modes. It is not related to the measuring speed. Only when the internal relais are switching some small glitches can be observed.The signal does not change when i change my probing setup. Only some (mainly 50 Hz) interference will be added. The best result could be obtained by using a banana to BNC adapter and a straight coax BNC cable that is connected directly to the scope input. Different cable lenghts didn't change anything, in my setup i used a 50cm cable.Using a probe adapter to connect the divider probe directly into the banana to BNC adapter gave some more 50 Hz interference.The level of the disturbing signal is always the same.
HP8924C Communications Service Monitor - Page 1
Forum section: electronics / testgear

author: TELCO
author_rank: Contributor
timestamp: August 10, 2014, 10:42:31 pm
content: Hello all. I am the proud owner of an HP8924C Communications Service Monitor and being in the two way radio business I absolutely love the beast, the only issue I see is that it is a true bench queen (60 pounds to carry around). I am wondering if there any others here in the EEVBlog using this pig that can share some of their experiences with it, good or bad. Thanks

author: KJDS
author_rank: Super Contributor
timestamp: August 11, 2014, 08:01:33 am
content: It's about the only one that I've never used.I'm very familiar with the Marconi 2955, A and RI'm even more familiar with the 2945I've had numerous Anritsu MT8801 series, which once you work out how to use the things are good, btu it takes a while. Orange LED for ON, Green LED for standby is just one of their peculiarities.

author: TELCO
author_rank: Contributor
timestamp: August 11, 2014, 02:34:28 pm
content: I have never used a Marconi or Anritsu. I am truly thinking about buying a Motorola R2600 or R2660 just because of the weight issue, that way I can lug it around to the repeater sites and such. But it is my understanding that the Motorola's are not as accurate as the HP's, do you have any input on this? I love my 8924C specially the SA/TG to tune duplexers and filters, mine is 100 watts so no problems with keying up into it. Thank you for the reply.
MSO-1104Z-S 3ch Analog, 16ch Digital - Page 1
Forum section: electronics / testgear

author: FrankT
author_rank: Regular Contributor
timestamp: August 14, 2014, 09:58:24 pm
content: I got my MSO-1104Z-S last night. I only had a few minutes to play with it.Pressed the Ch1 button - 1 Channel.Pressed the Ch2 button - 2 Channels.Pressed the Ch3 button - 3 Channels.Pressed the Ch4 button - 4 Channels.Pressed the LA button - Channel 4 turns off, the display says Channel 4 disabled, and the LA lights up. So I only have 3 analog channels and the digital channels simultaneously.I hope I just have to RTM .

author: John South
author_rank: Contributor
timestamp: August 15, 2014, 02:29:31 am
content: Hi Frank - Your unit is actually functioning ok.The MSO version of the DS1000Z must be sharing some resources with the DSO channels so if using 8 logic channels then you have 3 DSO channels , if using 16 then you have 2. See the attached from the manual.I see you are from Australia - if this is an issue and you purchased from Emona or other local reseller please contact me.Thanks

author: Electro Fan
author_rank: Super Contributor
timestamp: August 15, 2014, 03:00:29 am
content: The note indicates this might only apply to the 1000 series; anyone with a MSO2000 see this note in the manual?

author: John South
author_rank: Contributor
timestamp: August 15, 2014, 03:15:50 am
content: Hi Electrofan - MSO2000 series has 2 ch DSO , 16 ch Logic at the same time.Probably been mentioned before but one thing to note is that if you are doing a decode on serial bus you can use any of the digital channels to trigger and also decode.

author: Mark_O
author_rank: Frequent Contributor
timestamp: August 15, 2014, 05:29:33 am
content: Quote from: John South on August 15, 2014, 02:29:31 amJohn, thanks a lot for that information! I was initially going to make a rude and unprofessional comment. Instead I'll just say I find that extremely surprising, given the way that Rigol is marketing the MSO1000z models:"xx MHz Bandwidth,1GSa/s sample rate, 4 analog channelsand16 digital channels MSO"Note it says AND, not OR. That borders on false advertising. It's certainly deceptive. No where in any of the promotional materials does it mention that "little tidbit". And I find it odd that the info you clipped is a Note in the Quick Start section of Chapter 1 (easily overlooked). It's not mentioned at all in Chapter 7, which describes all the details of the digital channels.Not finding this out until after a purchase would not tend to make one a happy camper. And since the existing sample memory is being reallocated, all you're really getting for your additional $250 is a 16-bit digital latching front-end, passive logic cable, and some flying leads.(I see now buried on the new Spec Sheet, it does reveal... "Number of Channels MSO1XX4Z/1XX4Z-S: 1,2 analog-channel + 16-digital-channelDS1XX4Z/1XX4Z-S: 4-analog-channel", which in itself isn't even accurate, since it omits the 4-analog mode on the MSO.)Oh, and I found their current marketing picture on their website... (4+16channels, which isfalse. It's 2+16, or 3+8, or 4+0.)
HP3458a: RAM TEST 1 HIGH after NVRAM replacement - Page 1
Forum section: electronics / testgear

author: fedora_88
author_rank: Newbie
timestamp: April 05, 2014, 04:34:48 pm
content: Hi everyone,today I replaced the 2 NVRAMs (DS1235Y-150 -> DS1230Y-150) of my HP3458a preventive, because they were datacode '89. The unit was in working condition before (Self test passed, correct readings in all ranges).After soldering in the two new RAMs (datacode 5/2013) the unit starts with "RAM TEST 1 HIGH" and only react to the Shift- and the Resetbutton. But after a reset it still shows "RAM TEST 1 HIGH" and don't boot any further.I already read the thread from the user "eurofox" in this forum and some topics in the voltnuts newsgroup but I can't find a soloution for my problem.Is it possible that the new RAMs are damaged? Or do I have to do some "special procedure" to fill the new RAMs. The unit still has firmware rev. 3. Will it help to upgrade to rev. 8 or 9? Is there any place I can download them (6 eeproms-version)?I was able to readout the content of the original DS1235 chips. Do you think it will help to burn this into the new RAMs? And yes, I will use sockets next time.Thanks in advance for your helpThomasPS:I replaced the CAL_RAM (DS1220Y) a couple of days before, but unfortunately the old chip had gone bad before, so I could not rescue the original calibration. After the change to a new DS1220Y I made a CAL with 10V/10k (only 0,005%) just to make sure it works properly. Maybe I will sent it in to agilent for "final calibration" after everything is working properly again.

author: Dr. Frank
author_rank: Super Contributor
timestamp: April 06, 2014, 06:55:01 am
content: Those two 32kB RAMs contain the working RAM memory for the 68000 µP and also instrument setup variables.If you replace both RAMs, you will get an error only on first power up; the instrument will then initialize the setup variables and their checksums, and afterwards everything is fine.No further action is needed.You should put all the RAMs on precision sockets right now, .. then you could plug in the old RAMs, which should still work, and determine, if the new RAMs are defective, or something else on the PCB.Inspect your soldering on the HIGH byte RAM.Yes, an update to 8 or 9 will definitely remove several bugs.There's obviously no practical difference between 8 and 9.And no, the content of version 9 is not on the net.That would be illegal, as agilent still makes money with upgrades on this instrument, still being in series production. (180$ for 6 EPROM version)Frank

author: dr equipment
author_rank: Newbie
timestamp: August 11, 2014, 02:18:15 pm
content: Hi,I have the same problem. You can fix it? Any sugestion?Thanks
ATTEN ATF20B Experiences? - Page 1
Forum section: electronics / testgear

author: UnEntitled
author_rank: Newbie
timestamp: August 09, 2014, 04:34:12 pm
content: Caught my eye with it's low price. I do need a function gen and was wondering if this one was worth it.

author: nctnico
author_rank: Super Contributor
timestamp: August 09, 2014, 04:44:33 pm
content: I have been eyeballing this function gen. as well but in the end I bought a Siglent SDG1010 which is a much better buy IMHO.

author: janoc
author_rank: Super Contributor
timestamp: August 09, 2014, 04:49:03 pm
content: Haven't used that particular generator, but Atten isn't known for qualityIf their test gear is of the same quality as the hot air gun I have from them (the same Dave reviewed on the blog), then you really get what you pay for - it will probably work, but I wouldn't rely on it for serious work or that it doesn't fail in the most inopportune moment.And that generator isn't all that cheap neither. If you are really cash strapped, I would look on eBay for a used one from a major brand or try to get one of the Rigol sig gens instead.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 11, 2014, 06:15:53 am
content: Quote from: UnEntitled on August 09, 2014, 04:34:12 pmI was looking at this one when I needed a low cost generator last year, but after having a closer look at one I quickly decided against it and got a Siglent SDG1020 instead. Yes, the Atten is cheap but that's about all that is positive.The USB port is non-functional as its not connected to anything internally. They just put it in as it gives people the impression they could put a USB drive in it.Really, just put in a few bucks more and get a Siglent SDG1000 instead.
do 384 x 288 thermal sensors cost less than 320 x 240 ones? - Page 1
Forum section: electronics / testgear

author: ixfd64
author_rank: Frequent Contributor
timestamp: August 02, 2014, 07:52:35 pm
content: I've noticed there are some lesser-known brands of 384 x 288 thermal cameras that cost less than the 320 x 240 cameras from better-known brands despite having 44% more resolution.For example, here are the cheapest 320 x 240 cameras from the three best-known companies, not including the hacked E4's:The FLIR E8 normally costs $5,995 (currently on sale for $3,995)The Fluke Ti32 is on sale at TEquipment.NET for $7,039.96The Testo 885-1 is on sale at TEquipment.NET for $7,815.75In comparison, here are the prices of three 384 x 288 cameras from less popular companies:TheTherm-App deviceonly costs $1,600 (currently on sale for $999)TheGeneral Tools GTi50starts at $4,784.13The HT Instruments THT70 costs $4,995 at TEquipment.NETSo I'm wondering: are 384 x 288 thermal sensors cheaper to produce than 320 x 240 ones? If so, then why do companies like FLIR and Fluke not switch to these sensors?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 02, 2014, 08:01:46 pm
content: Quote from: ixfd64 on August 02, 2014, 07:52:35 pmIt's just a case of there being very few players in the market - the small fry have to sell cheaper just to get noticed.There is no doubt that the manufacturing cost of the sensor+lens used in the Ex is much lower than other sensors as it doesn't have the conventional expensive hermetically sealed package.

author: ixfd64
author_rank: Frequent Contributor
timestamp: August 03, 2014, 10:21:25 pm
content: Yeah, I figured that was the case. Do you know if the lesser-known brands are any good? It's damn near impossible to find reviews for cameras other those from those three companies.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 03, 2014, 10:33:44 pm
content: Quote from: ixfd64 on August 03, 2014, 10:21:25 pmI doubt there's much difference, assuming they meet their specs - I suspect a lot of the performance comes down to how well they are factory calibrated rather than sensor differences.

author: ixfd64
author_rank: Frequent Contributor
timestamp: August 09, 2014, 05:35:22 pm
content: Last year, I was asking if anyone had experience with the General Tools thermal imagers. I did some research and discovered that General Tools does not actually manufacture the Predator cameras. Rather, they are made by a Chinese OEM calledSATunder the HotFind series. SAT manufactures the same hardware for several different companies, hence why they are all nearly identical:ThePTI seriesfrom Process SensorsThePredator seriesfrom General ToolsTheIC080 seriesfrom TrotecHereis a review of the Trotec camera; I'd imagine the other ones would be very similar.
Scope voltage, probe voltage, can someone explain me how it work? - Page 1
Forum section: electronics / testgear

author: asgard20032
author_rank: Regular Contributor
timestamp: August 08, 2014, 03:56:12 pm
content: If my probe say it can support up to 10kv, does it mean that I can apply like 9kv to it, or shall I also refer to scope specification? (considering its a probe that match impedance of scope)Im a little lost when I look at scope specification, never sure if it talk about scope or probe voltage limit, which one i should refer when for input voltage without broking thing up...

author: KedasProbe
author_rank: Frequent Contributor
timestamp: August 08, 2014, 05:09:53 pm
content: The properties of your probe are the properties of your probe, they don't know which scope you have.You have to check what the max. voltage of your scope is, multiply that with the probe ratio and you will know what the max. voltage is the scope can handle with that probe.But if for example you calculate 2000V and the probes max. is 600V then it's 600V you have to stay below the max. specification of your probe AND your scope.

author: bktemp
author_rank: Super Contributor
timestamp: August 08, 2014, 05:42:00 pm
content: When switching to AC coupling on the scope, the max voltage is limited by the scope regardless of the division factor of the probe, because a probe is basically a series resistor. When switching to ac coupling, the coupling capacitor in the scope sees the full input voltage.

author: David Hess
author_rank: Super Contributor
timestamp: August 08, 2014, 06:52:03 pm
content: Quote from: bktemp on August 08, 2014, 05:42:00 pmThis depends on how the probe is designed. Many high voltage probes include an internal resistive shunt at the oscilloscope end which prevents this problem. You can determine this by checking the specified input resistance of the probe; a x100 probe with a 100 MOhm input lacks the shunt but a x100 probe with a lower input resistance like 10 MOhm or 50 MOhm includes it.
Is a Rigol MSO4014 identical with MSO4054 hardware wise? - Page 1
Forum section: electronics / testgear

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 31, 2014, 09:33:38 am
content: Are both scopes identical in hardware?Has it been tested that the patched version really can measure up to 500MHz?

author: pascal_sweden
author_rank: Super Contributor
timestamp: August 04, 2014, 12:41:41 pm
content: I like to re-activate this post, as I have not received any feedback yet.Basically I want to verify if the MSO4014 would be the cheapest possible option to get a scope which can be hacked to the most expensive scope from Rigol out there (except the DS6000 series of course).What are the negative things about the MSO4000 series? Will they deliver a new major SW update this year to fix all these issues?

author: salvix
author_rank: Newbie
timestamp: August 07, 2014, 03:32:57 pm
content: Quote from: pascal_sweden on January 31, 2014, 09:33:38 amYes. Yes.

author: Mark_O
author_rank: Frequent Contributor
timestamp: August 08, 2014, 08:05:04 am
content: Quote from: pascal_sweden on August 04, 2014, 12:41:41 pmCost, and bugs.QuoteThere's no one here who can answer that question, and Rigol isn't saying. But it's pretty safe to assume, based on prior history, that the answer to that is "no". They've had plenty of time with the 4000 to address anything they think is worth their efforts, and issues still remain. Now some of those issues may be of no importance to you, but others may be critical, and void the large investment in $$$ the 4000 requires.
Rigol DS2000 ,  failures and RMA reports - Page 1
Forum section: electronics / testgear

author: Teneyes
author_rank: Frequent Contributor
timestamp: December 15, 2013, 11:52:35 am
content: Hello All Rigol Owners, this Blog is for owners who have had failures of their DS2000 andRigol has issued a RMA.For me I have had 2 failures:.1. Some of My DSO front panel push button failed and Rigol sent me a different repaired DS2000, they reported a circuit board had burn traces and a replacement board would take months ( high demand at that time.)2. After hearing of heatsink retaining clips coming lose, I shook my DSO and the clips were rattling inside, I fished them out and sent the DSO to Rigol, it was a quick return only 2 days at Rigol and Rigol paid shipping both ways. Excellent service.Note the tool in the picture. I think manufacturing has corrected this flaw.It would nice to hear of other problems owners have had

author: Marc M.
author_rank: Regular Contributor
timestamp: December 17, 2013, 08:13:46 am
content: I posted about an issue with my DS2072 in late November which is causing spurious garbage on both channels with nothing connected to the inputs. OP is here:https://www.eevblog.com/forum/testgear/rigol-ds2072-is-dying!!Since that posting the problem has degenerated to the point I can't get it to clear up even after an hour of being powered up.I initially contacted TEquipment on Dec.10th regarding the issue. I received a reply back the following day indicating warranty issues were handled by Rigol NA and provided contact info.I e-mailed Rigol NA thru their website on Dec. 11th explaining the issue. I received a reply the next day from Rigol NA requesting some additional information, primarily the S/N of the defective unit. This was sent to Rigol on the following day Dec. 13th. At this time I also asked about Rigol picking up the shipping both ways as they did not offer to pay it.I received the RMA number from Rigol NA on Dec. 16th. They explained that Rigol only offers to pay all shipping within 30 days from date of purchase but made an exception and also sent a return shipping label via FedEx.I've got car issues this week so I won't get it shipped out until next week. I'll update this when I get it back.

author: savageautomate
author_rank: Unknown
timestamp: July 23, 2014, 03:50:50 pm
content: I just notice the heatsink clip rattling around in my DS2072. I have contacted Rigol support for RMA. I'll report back my support experience.

author: savageautomate
author_rank: Unknown
timestamp: August 07, 2014, 08:36:55 pm
content: Status update ... Unit sent in for RMA repair. Rigol would not pay for shipment to their repair center. Hopefully it comes back in one piece.