hybridfree/eevblog-posts huggingface dataset:
How to test a cable with a VC60B+ - Page 1
Forum section: electronics / testgear

author: Dude McGee
author_rank: Newbie
timestamp: April 20, 2018, 10:49:26 am
content: Hello,I've purchased a VC60B+ a few days ago, which is an insulation tester branded under different names (Victor, Vici, and others).It came with a Chinese manual which I can't read. On the net you find these manuals:https://core-electronics.com.au/attachments/VC60B+%20User%20Manual%20(English).pdfhttp://www.analogti.com/document/VC60B.pdfhttp://micromir-nn.ru/insulation/VC60B.pdfThe sentence which confuses me is this:"6、When measuring cable, connect G Terminal to the protection loop."Normally, you have to connect L and E, the two outmost terminals, in order to measure the isolation resistance. For which purpose should I have to use G? And, should G be connected to the earth conductor of the cable? And, what could be the possibly adverse effect if I don't comply to this rule?The biggest problem with such a low-cost device is probably that you don't receive a proper and responsibly written manual in a good language, at least neither in German nor in English. These translations from Chinese to whatever are between totally useless or at least dangerously confusing... So, to get an advice from an experienced electrician would be great! I'm just a beginner and mere amateur...Thanks a lot beforehand,have a good time,Hartmut

author: Maxlor
author_rank: Frequent Contributor
timestamp: April 20, 2018, 11:19:08 am
content: Have a look at the manual for this Fluke insulation tester:https://www.distrelec.ch/Web/Downloads/nu/al/FLUKE-1550C-1555_eng_manual.pdf(Section "Guard Terminal Use" on the 30th page, labelled page 12.)It explains the use of the Guard terminal quite well.

author: Dude McGee
author_rank: Newbie
timestamp: April 20, 2018, 01:35:08 pm
content: That brings me one step further, thanks! So, to my understanding, I would neither enhance accuracy nor safety when connecting a standard household cable's ground wire to G. I assume that the cable type shown in this chapter is something different than the cables you typically use in home environments.
MSO1074Z Troubleshooting bad LA channel - Page 1
Forum section: electronics / testgear

author: qwertymodo
author_rank: Contributor
timestamp: March 07, 2018, 11:44:05 pm
content: I've had my MSO1074Z for a couple of years now and have been really happy with it, but the last couple of weeks, I've been using the logic analyzer to debug what I thought was a problem with my rusty verilog, but it turns out, channel 3 of my logic analyzer is badBasically, I have a signal that should be a simple 50% square wave, but instead of seeing a square wave, I just see a tiny pulse on what should have been the posedge. Sometimes I don't even get that. I've tried swapping lead clips, even the whole lead wire, attaching that lead to different signals, and attaching multiple leads to the same signal, and everything seems to point to it being a problem with the channel. When I swap lead clips/wires, the problem remains on channel 3, and the channel 3 clips/wires work fine on other channels. When I hook up to other signals I see the same behavior. When I hook up multiple channels to the same signal on the device, the other channels display it properly. Every once in awhile, it does seem to start working properly, but only briefly. I've attached a screenshot which demonstrates channel 3 and 6 both connected to the same signal pin, with 6 properly displaying the square wave and 3 showing the issue. I've updated the firmware to the latest (4.4.3.2, which displays as 4.4.SP3) and ran a self calibration, no change. Any thoughts on further troubleshooting?

author: 2A03
author_rank: Contributor
timestamp: March 09, 2018, 12:10:37 pm
content: Try changing the threshold voltage of LA.

author: qwertymodo
author_rank: Contributor
timestamp: March 19, 2018, 09:33:44 pm
content: I tried that, no difference. And it's only on that one channel. All of the other channels work just fine on that same signal for all of the threshold values I tested.

author: Tangent_Tracker
author_rank: Regular Contributor
timestamp: April 19, 2018, 01:14:25 pm
content: Did you get to the bottom of this without returning?
Problem with TEK THS720 - Page 1
Forum section: electronics / testgear

author: mmoss111
author_rank: Newbie
timestamp: April 19, 2018, 09:02:34 pm
content: I think that the measured input resistance to channel 1 should be 1 megohm with no probe connected. I get 50K to 200K ohms and can not calibrate the probe.I have heard that a coax cable from the connector to the board developes some kind of problem perhaps a partial short or some kind of leakage. Does this cable often go bad like this? Can it be replaced with some RG174U or mike cable or some other type of shielded cable?
DS2102E (Not A) unlock - Page 1
Forum section: electronics / testgear

author: Salrus
author_rank: Newbie
timestamp: April 19, 2018, 08:05:06 pm
content: Hi,I have a DS2102E I would like to unlock and I have tried DS2000A unlocker (won't read the custom firmware file) and riglol keygen and it responds License Unavailable any advice from anyoneSalrusEditI figured it out by using a German program to dump the memory to get the private key
General Electric DPI-620 calibrator repair video - Page 1
Forum section: electronics / testgear

author: PA4TIM
author_rank: Super Contributor
timestamp: April 19, 2018, 06:24:09 am
content: This instrument had a missing power supply input connector, a problem with the power button , a battery problem and someone had been inside it and killed the antenna. I repaired the antenna, modified the powerbutton, rebuild the solder pads of the power supply connector and fooled the BMS to get it out of sleep mode.Not something you see everyday, these calibrators are pretty expensive and the problems are fun to repair.https://youtu.be/nFQxVm6fIdg
Peaktech 4350 Clamp Meter - Page 1
Forum section: electronics / testgear

author: Spike101
author_rank: Contributor
timestamp: February 04, 2015, 08:37:59 pm
content: Hi everyone,I was thinking about getting a DC clamp meter, and i stumbled on this Peaktech 4350 (see herehttp://www.peaktech.de/productdetail/kategorie/echteffektiv-stromzangenmessgeraete/produkt/peaktech-4350.html). Is it any good? It's rather cheap (about 65 Euros) but has a nice resolution of 1mA for up to 5A. I can't find any reviews or opinions about that thing on the net, but i guess it's some OEM device, so there's probably enough out there but i don't know what to search for.thanks for any opinions

author: omgfire
author_rank: Regular Contributor
timestamp: February 04, 2015, 10:15:43 pm
content: Quote from: Spike101 on February 04, 2015, 08:37:59 pmWith claimed accuracy +/- 2,5 % +30 dgt. It is 60mA window for 0mA.Uni-T UT210E has better claims for €30.

author: Spike101
author_rank: Contributor
timestamp: February 05, 2015, 07:33:21 am
content: Ah nice, thanks for the suggestion. Looks like the better option. I'll see if I can find this one!

author: omgfire
author_rank: Regular Contributor
timestamp: February 05, 2015, 08:53:51 am
content: Here is a review of Uni-T UT210Ehttps://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/

author: SvenL
author_rank: Newbie
timestamp: April 18, 2018, 10:43:03 am
content: I have such a unit in use!It seems to be quite accurate compared to the Rhode&Schwarz multimeter at the company. In DC current measurements it differs slightly about 1-2 mA in the lower measurement range.As with any DC clamp meter, zeroing the device before measurement is important.I would recommend that clamp meter from my point of view!Sven

author: mcinque
author_rank: Unknown
timestamp: April 18, 2018, 09:01:42 pm
content: Personally I would avoid Peaktech for any instrument: they are only rebranded and overpriced items without any single added value. You can get the same from the original manufacturer for less price.Also, their support was quite useless to me: I asked them why I should choose their PSUs instead Manson's: since they are the same units I asked only if they request to Manson different components for their units or if there is any difference between them but they felt literally offended by my request and quit the conversation.For me, Peaktech is "don't touch it even with a 6ft. pole."

author: Performa01
author_rank: Super Contributor
timestamp: April 19, 2018, 03:22:27 am
content: Quote from: mcinque on April 18, 2018, 09:01:42 pmFully agree. Why would anyone pay a premium for a rebadge that absolutely adds no benefit, not even prestige, since it's done by a low-reputation C-brand?
Oscilloscope for power measurements - Page 1
Forum section: electronics / testgear

author: drtube
author_rank: Contributor
timestamp: April 18, 2018, 10:53:30 pm
content: Hello everyone!!I am looking for an oscilloscope capable of multiplying two signals and showing the result as an extra signal/trace. The main purpose is power measurements of DC motors, non-linear loads, etcThe main idea is to set the third trace as:3rd signal: Ch1xCh2 (to see power waveform)and3rd signal: Avg(Ch1xCh2) (to see average power of the load)Typically, the voltage is a square wave between 65 and 200 volts peak and the frequency is between 50 to 500 Hz. The current is between 1 and 5 amps of different types of waves, same frequency.I have the Tektronix P6042 current probe (still working good!!!) so if the oscilloscope has a 50 ohm input, better. I'm quite low on budget, what would you recommend? I saw rigol MSO series but they start at $ 2000 min.Thanks in advanceDrTube

author: llkiwi2006
author_rank: Regular Contributor
timestamp: April 18, 2018, 11:11:55 pm
content: Use a 50 ohm through terminator, and any scope you want. Pretty much any scope is capable of doing multiplication. Use the forum search feature to find all the past discussions on scope recommendations. If you only want to spend $350-$500, the rigol ds1054z is a pretty popular choice, and the new sds1104x-e is also worth considering.

author: drtube
author_rank: Contributor
timestamp: April 19, 2018, 02:55:51 am
content: Thanks for the answer! I think I'll go with DS1054Z, it can perform 2 layers of calculation (i.e. Intg(CH1XCH2)), while Siglent cannot.Do you know if some of these entry level scopes feature more deep calculations? I mean arbitrary math expressions, mixing channels, math functions, constants, etcRegards,DrTube

author: Performa01
author_rank: Super Contributor
timestamp: April 19, 2018, 03:07:43 am
content: Quote from: drtube on April 19, 2018, 02:55:51 amIf you're looking for high-end features like (really) advanced math and full use of a HD screen with multiple view ports on a budget scope, there aren't many choices left:https://www.picotech.com/oscilloscope/2000/picoscope-2000-overviewBTW, street prices are usually lower than what is shown on this web site.

author: JPortici
author_rank: Super Contributor
timestamp: April 19, 2018, 06:14:14 am
content: ^ true, although you will need special care as max Vin is +/-50V.For a 10x probe this means up to 500V peak, but you risk damaging the instrument and whatever is connected to it in a moment of distraction.
Tektronix  222 Display Rotated - Page 1
Forum section: electronics / testgear

author: teconomy
author_rank: Newbie
timestamp: April 18, 2018, 03:09:54 pm
content: Hello, I have a Tektronix 222 scope in great condition except the display is rotated. See attached photos.I have it pulled apart and have the service manual and have tried all the adjustments that I can find but none will correct the issue.Any thoughts?Thank you

author: Rolo
author_rank: Regular Contributor
timestamp: April 18, 2018, 04:33:11 pm
content: This is a CRT so the coil packet could be out of position. I'm no expert but you can look if it can move and try turning it, beware of VERY HIGH voltage inside.

author: teconomy
author_rank: Newbie
timestamp: April 18, 2018, 04:56:05 pm
content: Hi and thank you for your reply,I tried to gently turn the base but it appears that it does not rotate. I am reluctant to apply too much torque in fear of breaking it.Thanks again!

author: ArcticGeek
author_rank: Regular Contributor
timestamp: April 18, 2018, 06:58:29 pm
content: I don't know much if anything about the 222 scope, but I would agree that it sure looks like the deflection yoke is rotated. There is usually a clamp somewhere on the yoke that needs to be loosed before it can be rotated - did you loosen the clamp?

author: edavid
author_rank: Super Contributor
timestamp: April 18, 2018, 07:33:37 pm
content: Quote from: ArcticGeek on April 18, 2018, 06:58:29 pmIt's an electrostatic deflection CRT, so there's no yoke.OP, what happens when you try to adjust HORIZ ALIGN and VERT ALIGN?

author: james_s
author_rank: Super Contributor
timestamp: April 18, 2018, 07:50:37 pm
content: Many scopes have a trace rotation coil, if this does then it may have become disconnected or whatever drives it has failed.

author: teconomy
author_rank: Newbie
timestamp: April 18, 2018, 08:47:47 pm
content: I just added an other photo of the interior of the scope.

author: teconomy
author_rank: Newbie
timestamp: April 18, 2018, 09:09:50 pm
content: When I adjust the HORIZ ALIGN and VERT ALIGN they appear to operate correctly in that they slide the display on the x an y axis respectively. They along with all of the other adjustment pots all appear to work fine however none of them address the issue of rotation.Thx

author: duak
author_rank: Super Contributor
timestamp: April 18, 2018, 11:56:38 pm
content: I downloaded a copy of the manual from Tek wiki:http://proxy.w140.com/tekwiki/wiki/222I see on page 3-7 in the last paragraph the 222 uses electronic trace rotation. I could imagine that too much of the X is being fed into the Y thus causing a major rotation or lozenging.I don't seem to see any schematics in the above manual so I can't offer any advice other that to check the values of all resistors near the Horizontal and Vertical align trimpots.Cheers,

author: james_s
author_rank: Super Contributor
timestamp: April 18, 2018, 11:59:46 pm
content: That sure is a neat little scope, I wish I had one.
Instek GDS-300 - Page 1
Forum section: electronics / testgear

author: haggy38
author_rank: Contributor
timestamp: April 19, 2018, 12:30:25 am
content: Hi guys,Looking for a portable scope, I find this one GW Instek GDS 300 series, it seems nice and sufficient for what I need, vintage audio restoration, small electronic projects, Rc and pinball machines.Any reviews so far? I know its not fluke but for $800 looks okGustavo

author: lypse
author_rank: Contributor
timestamp: April 19, 2018, 12:42:28 am
content: Please note that is is only CAT II, that is similar to most bench scopes.I have not seen any Flukes rated that low :|

author: haggy38
author_rank: Contributor
timestamp: April 19, 2018, 01:18:13 am
content: Agreed, but don't need more than that, hope any member here got it already an share some experience. Pretty sure is in the same level as Siglent, Hantek, etcGustavo

author: wraper
author_rank: Unknown
timestamp: April 19, 2018, 01:23:10 am
content: You may also look at Micsig scopes, they are pretty decent if you want portable.Quote from: lypse on April 19, 2018, 12:42:28 amIt is certainly rated higher than bench scopes (CAT II 600VRMS, CAT III 300VRMS). Bench scopes usually are rated for something like CAT I 300VRMS

author: haggy38
author_rank: Contributor
timestamp: April 19, 2018, 01:44:16 am
content: Thanks for your reply, I really like its touchscreen and can use meter and oscilloscope at the same time, Micsig look interesting too.Gustavo

author: lypse
author_rank: Contributor
timestamp: April 19, 2018, 02:31:48 am
content: Quote from: wraper on April 19, 2018, 01:23:10 amBut the scope is "only" CAT II 300VRMS, so granted still higher than many bench scopes, and thus not rated for measuring at distribution panels or fixed installations.Also, I think the flukes have isolated channels.. this one requires differential probes... it may be, that can be considered enough to use the probes rating instead then.Btw, I think there is a promotion going for them if you are in USA.http://www.gwinstek.com/en-US/Page/ECEDHA_Education_Promotion

author: haggy38
author_rank: Contributor
timestamp: April 19, 2018, 03:20:39 am
content: Wow thanks, I will put the trigger on the GDS 207!!
Recommend an AC/DC power meter - Page 1
Forum section: electronics / testgear

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: March 17, 2018, 01:08:47 am
content: I've been looking to buy a power meter for some time now but they seem to be very rare for some reason.I want either a handheld or bench meter to accurately measure AC and DC power with other features as a bonus.Been having a hard time finding something suitable for my needs. Maybe someone can help me out.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 17, 2018, 01:16:27 am
content: What are your requirements?

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: March 17, 2018, 01:30:36 am
content: Quote from: joeqsmith on March 17, 2018, 01:16:27 amI am on the market for a bench multimeter so if I can find one with a power function and graphing capabilities I'd be sold if the price is right (1500$ or less)

author: joeqsmith
author_rank: Super Contributor
timestamp: March 17, 2018, 01:40:08 am
content: That's it, just DC and AC for $1500. So we can assume 1Vpeak max, DC to 1Hz and 0 - 1fA, with a single channel is good enough for your needs. I think I would save the$1500 and just get a couple of meters and calculate it.

author: drummerdimitri
author_rank: Frequent Contributor
timestamp: April 18, 2018, 08:45:36 pm
content: Quote from: joeqsmith on March 17, 2018, 01:40:08 amI will be measuring mostly DC power but AC mains power as well.I need at least 300V, 1KHz, single channel, 10A etc.Also, a 4 wire measurement would be ideal to avoid incorrect power measurements due to voltage drop.I like the Metrahit Energy DMM but is only works in 3 wire config...
Calibrating a HP 431C power meter - Page 1
Forum section: electronics / testgear

author: LazyJack
author_rank: Frequent Contributor
timestamp: April 18, 2018, 07:47:59 pm
content: Hi,I recently scored a nice HP 431C power meter with cable and 8478B thermistor. (And also a 11527A adaptor, which is not required for this setup.)I cleaned it, and seem to work fine, I can zero it, reads about right, but i have no idea how accurate it is. There is about 0.5 dB difference between the meter on my 8640B, and the power meter, but the signal gen's level meter is far from precision equipment.The 431C was last calibrated some 20 years ago. The manual calls for the 8402B calibrator to calibrate it. Which is usually available on eBay, but would be uneconomical to get it because of the shipping cost. And that still doesn't calibrate the thermistor.Anyway, do you have any idea on how I could calibrate or at least verify the accuracy of this meter? The sensor reads from 100MHz, so I can't just do an RMS measurement. Although, I do have a HP 3406A sampling voltmeter, which in theory can calibrate with its own calibrator, but that has not been calibrated for a long time, and I had to do repairs in it anyway. I do have 300MHz scope, but that is not precision equipment, either.I don't have an other power meter or a calibrated power RF source.

author: LazyJack
author_rank: Frequent Contributor
timestamp: April 18, 2018, 08:04:20 pm
content: Well, the RMS measurement on the scope (Tek 2440) and the 431C agree, so this indicates that the sig gen's level meter is showing a bit low.But the original question still stands, is there a DIY way to calibrate this old power meter?

author: Tony_G
author_rank: Super Contributor
timestamp: April 18, 2018, 08:08:48 pm
content: That sensor can read from 10MHz to 18GHz - The issue you're going to run into is that the sensor has a calibration table that changes as frequency changes so you really need to characterize it over at least the frequency range you're interested in. I don't think there is any shortcut to that unless you have a source that you already know its values and uncertainties over that range.You might want to see if your national standards lab will do a thermistor mount calibration (but then you're back at the 431C calibration as it is a DC substitution meter and it'll introduce errors).Hopefully some others have better suggestions for you.TonyG

author: LazyJack
author_rank: Frequent Contributor
timestamp: April 18, 2018, 08:29:09 pm
content: Thanks. I do have the cal factor table for the sensor, but of course, that is probably not valid anymore. Since the whole instrument cost 35 bucks, I don't think taking it to a cal lab is worth it. Probably I'll look around if I can do some comparison with a good power meter, that should be sufficient for my needs.
Measuring signals in high noise environment  - Page 1
Forum section: electronics / testgear

author: Crazy_Engineer
author_rank: Contributor
timestamp: April 18, 2018, 06:18:18 pm
content: How do you accurately measure signals when there is a lot of EMF in the work area? I am currently using my DS1054Z to try to measure signals on a project that involves relays. Unfortunately switching the relays produce so much emf that my o-scope reads a few volts if theunconnectedprobes are anywhere near the board.

author: Kleinstein
author_rank: Super Contributor
timestamp: April 18, 2018, 06:36:58 pm
content: As long as the signal to measure things get much better when the probe is connected. It is normal for the high impedance probe to pic up quite some signal from the environment, usually mainly 50/60 Hz mains frequency.It might be with adding free-wheeling diodes if the relays are DC. Or snubbers if AC. Normally Relays don'T produce so much EMF trouble. Difficult are things like an arc lamp or arc-welding.

author: Crazy_Engineer
author_rank: Contributor
timestamp: April 18, 2018, 08:07:02 pm
content: The relays have flyback diodes, and the probes are set to their lowest impedance. Perhaps wrapping the probes in conductive tape will shield them from the EMF?

author: CopperCone
author_rank: Super Contributor
timestamp: April 18, 2018, 08:24:44 pm
content: try removing the bayonet tip/hook from the probe, and disconnecting the ground wire. Do you still get pickup?
R&S FPC1500 Spectrum Vector Analyzer - Page 1
Forum section: electronics / testgear

author: simone.pignatti
author_rank: Frequent Contributor
timestamp: March 26, 2018, 02:18:54 pm
content: As I said in a different topic, "mark my words"Here is a new spectrum analyzer with integrated single port VNA. from the brochure it seems the technology is the same of the upcoming Siglent.Quote from the R&S document: "vector network analyzer that utilizes an integrated VSWR bridge to achieve one-port vector network analysis, with a Smith chart display available. Having an integrated VSWR bridge means there is no need to mount/dismount an external bridge during test operation."It seems that many users will have a new toy to play with, including radio enthusiasts .To activate the VNA you will need option K42.brochure latest release:https://www.batterfly.com/PDF/rohde-schwarz/fpc1500/FPC_bro_en_5214-7112-12_v0400.pdf

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 16, 2018, 03:54:04 pm
content: https://www.testequity.com/products/34885/#tabgroupwell do i have to copy paste?Quote"Affordable"

author: simone.pignatti
author_rank: Frequent Contributor
timestamp: April 17, 2018, 06:34:54 pm
content: We have now the unit for few days and we are testing it with antennas and filters. The unit works very smoothly and it jump from one mode to the other very quickly. Have shown it to few customers, one of them developing DAB antennas and they were really happy with the result. I can see the best configuration is FPC1500 + preamplifier + VNA . At this stage we give the unit with a free TekBox kit of 44 pieces of the most common 50 Ohm coaxial adapters.Today we had a training session at the office together with the oscilloscope RTE1000 , very impressive. One picture from today.In case you are based in Italy and what to set a demo feel free to contact me!

author: bozidarms
author_rank: Regular Contributor
timestamp: April 17, 2018, 08:22:29 pm
content: FPC1500Spectral purity SSB phase noise: Carrier offset30kHz!!!<–88dBc(1Hz),–92dBc(1Hz)(typ.)SSA3000X: <-98dBc/Hz@1 GHz,10kHzoffsetSVA1000X:-99 dBc/Hz@1 GHz10 kHzComment is not necessary!

author: simone.pignatti
author_rank: Frequent Contributor
timestamp: April 17, 2018, 08:28:45 pm
content: SSA3000X doesn’t do VNASVA1000X on the paper looks good and we will have it soon. Then we can compare.
Hitachi V-209 OScope battery powered - Page 1
Forum section: electronics / testgear

author: sarel.wagner
author_rank: Regular Contributor
timestamp: April 16, 2018, 03:54:32 pm
content: Got this oscope recently to be my dedicated signal tracer (XY) analyser. It is battery (NiCad) and mains powered. The scope was in perfect condition, excep for the internal batteries. So this happened today:Old NiCad packNew 4000mAh cells, NiMH, can be charged by the built in charger.Soldering the cells together, using desolder braid, after a cleaning, fluxing I and tinnig first. The metal did not even feel hot directly after soldering.Tools used.Packaging.Tight fit.And running on the new pack....

author: Diabolo
author_rank: Regular Contributor
timestamp: April 16, 2018, 04:40:17 pm
content: Hello,You replaced an NI-CD battery pack with an NI-MH battery pack.How is the load and the load detection full ?Regards,Diabolo

author: sarel.wagner
author_rank: Regular Contributor
timestamp: April 16, 2018, 04:53:59 pm
content: It uses the build in charger for that. The two cell chemistries are close as far as voltage are concerned. See Dave’s video here:
SDS2304X control via VXI11 - Page 1
Forum section: electronics / testgear

author: mehrdadg
author_rank: Newbie
timestamp: April 15, 2018, 01:19:25 pm
content: HI allI recently purchased SDS2304X scope and for the life of me I can't figure out how to control this instrument via lan. I have tried every suggestion from the MFG'er, googling, etc. and still having issues.If I install the EasyScopeX by itself, I can make the connection without any problem.When I install NI runtime executable, still no issue.When I install full blown NI-Visa, then everything stops working (100% followed instruction). two other instruments show up properly (SSA3032X and SDG2042X).if I uninstall the full NI-Visa (full version), then I can get the EasyScopeX to work again.However, when I try to use Python to program this device remotely, I can't connect to it.I am wondering if I made a wrong choice on buying the 4 channel scope! my 2 channel Rigol works just fine:(thanksMG

author: tautech
author_rank: Super Contributor
timestamp: April 15, 2018, 08:28:37 pm
content: Welcome to the forum.Please check you have the latest firmware installed: 1.2.2.2R10https://www.siglentamerica.com/service-and-support/firmware-software/digital-oscilloscopes/#sds2000x-seriesHere's some app notes for LAN connectivity:https://www.siglentamerica.com/application-notes/sds2000x-series/
Keysight parts ordering, what am I not seeing? - Page 1
Forum section: electronics / testgear

author: CJay
author_rank: Super Contributor
timestamp: April 24, 2018, 10:44:36 am
content: I've just scored a *really* clean Agilent U1731B LCR meter on eBay but it's missing the stand (no drama at all, it was clearly stated in the listing) so off I went to Keysight's website, registered and WTF, even though I can find the parts, prices in Sterling, Find A Part is only for the US?I can't seem to find out how to order parts direct, I have a horrible feeling I'm going to end up paying a huge distributor markup so how do I order parts in the UK direct or could some kind soul who has a Keysight account please volunteer to order it for me (costs covered etc.)?

author: mbless
author_rank: Regular Contributor
timestamp: April 24, 2018, 06:13:49 pm
content: What exactly is the problem? Can you add the part to the cart? Can you click the "Checkout" button?I just went through this process (for US), and you have to request additional access to buy parts.

author: CJay
author_rank: Super Contributor
timestamp: April 25, 2018, 10:01:48 am
content: I can't even see a cart, I'll look further for any extra access necessary though.Find A Part does seem to suggest it's US only though?

author: mbless
author_rank: Regular Contributor
timestamp: April 25, 2018, 02:27:18 pm
content: I'm not sure about it being US only. Note that if your order is less than $50USD there is a $20USD processing/shipping fee. I only need to order a couple of $2 parts so maybe we can work something out.

author: CJay
author_rank: Super Contributor
timestamp: April 25, 2018, 02:38:15 pm
content: Then I'd be paying Keysight the mark up, ugh..I need the tilting stand for the meter which is only ~$3.50I understand why it's necessary to add the handling charge but wow, what a PITA if all i need is one really cheap part.

author: mbless
author_rank: Regular Contributor
timestamp: April 25, 2018, 02:54:26 pm
content: Agreed. I'm trying to find a compatible replacement knob through Digikey to avoid the ridiculous price. If that fails, maybe I'll buy from Keysight...
EIP 5xx Frequency counters? - Page 1
Forum section: electronics / testgear

author: Stray Electron
author_rank: Super Contributor
timestamp: April 13, 2018, 05:42:48 pm
content: Can anyone explain the difference between the 5xxA and the 5xxB counters? Also does anyone have a list of the circuit cards used in the various models? Finally, on some models, EIP offered an option 12, "Improved Sensitivity Guaranteed". Does anyone know what was involved with that? My manual mentions it under the options but it's not mentioned anywhere else that I can find. Even the sensitivity specifications fail to mention it.

author: HighPrecision
author_rank: Unknown
timestamp: April 14, 2018, 08:34:56 pm
content: Quote from: Stray Electron on April 13, 2018, 05:42:48 pmx=5 for 18/20 GHz modelsx=8 for 26.5 GHz models53x/53xB: lowest price units, missing some functions of higher models (i.e. freq. limits)54x/54xA/54xB: standard units57x/57xB: as 54x with source locking circuits added58x/58xB/58xC/59xx: Pulse counters (different HW)25B/28B: as 54xB models in small case and band 3 power meter standard'A' models exists only for 545/5485xx(A) <> 5xxB major differences are upgraded CPU (double clock), new firmware structure, new EEPROM for cal data, GPIB interface standard (no opt.08) and others.Quote53x/54x and 57x use similar cards, differences are related to CCN numbers of production history, small or big modifications on components. 'B' models have a totally different CPU card and major mods on some other.in the 'B' transition from older models there is a big confusion, new CPU card is installed in some old models, in example: 545A CCN 2209, it's also confirmed by the CCN 2209 manual.Yes, exist a list of cards P/N related to CCN numbers.QuoteI know that the lowest price 53x/53xB counters have a standardminimumguaranteed sensitivity on band 3 lower than others models, 5dB less, and the Opt.12 upgrade this at the same level of 54xx/57xx models.

author: Stray Electron
author_rank: Super Contributor
timestamp: April 14, 2018, 09:01:34 pm
content: Thanks. That's exactly the kind of information that I was looking for.
HP 437B Power meter analog movement stuck - Page 1
Forum section: electronics / testgear

author: EE-digger
author_rank: Frequent Contributor
timestamp: April 13, 2018, 10:54:00 pm
content: I have a near perfect 437B which I'm thinking of selling, having upgrade recently.The only problem is the darned analog meter. Is there an easy way to un-stick it? I haven't looked closely but does it get stuck on its own zero adjustment post? (if it has one).Thanks.
Looking for some decent input protection schematic - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: April 13, 2018, 08:02:43 am
content: Hi!I`m gonna make diy voltmeter&milliommeter just for funAnd I`m looking now for some decent input protection schematicAny ideas?also it may be interesting for peoples who wants to upgrade cheap DDMs

author: WhichEnt2
author_rank: Regular Contributor
timestamp: April 13, 2018, 10:43:50 am
content: You can check Fluke's 83_85_87smeng0500.pdf doc (83, 85, 87 service manual) which contains a lot of schematics, ever with signal flows for every mode. It also have a short description about protection circuits in "theory of operation" section.
TDS520A NVRAM Backup - Page 1
Forum section: electronics / testgear

author: pianoman
author_rank: Newbie
timestamp: April 12, 2018, 03:38:09 am
content: I recently found out that my two NVRAM chips on my TDS520A oscilloscope are corrupt. Does anyone have image files for these devices that they can send to me or point me to a lace where I can find them.Thanks

author: fenugrec
author_rank: Frequent Contributor
timestamp: April 12, 2018, 03:30:30 pm
content: userstrickalready replied to you on the Tek forums ?

author: pianoman
author_rank: Newbie
timestamp: April 12, 2018, 11:35:27 pm
content: Got it Thanks. I am still looking for the Timekeeper image file so if anyone has and image file for the DS1486 for the TDS520A I would greatly appreciate it.
Power source KPS3005D - Page 1
Forum section: electronics / testgear

author: elebot
author_rank: Contributor
timestamp: April 12, 2018, 05:37:24 pm
content: I have recently bought this Chinese power source on eBay and thought it would be useful to share some info.It is a fairly standard 150W switch mode power supply providing 30V / 5A (actually goes a little bit higher 32V / 5.1A), with "digital control".In Europe it is being sold for about 40 Euros on eBay delivered and for example in Germany they have local stock so no problems with customs and quick delivery (in my case anyway).There are several other models in this line offering higher power and/or serial interface. Unfortunately by omitting the serial interface they introduced issue of missing grounding which leads to a somewhat erratic behaviour straight out of the box...This is (together with the fix) documented on these videos (not mine):Below are some pictures of the internals and complete schematic. As you can see almost half of the box is empty :-)Looks like standard PC power supply based on TL494.There is no PFC (in Europe from 80W should be).There is no real output power switch. The CPU just disables/enables the control IC. Which together with the big filtering capacitors leads to "soft start" and stop (depending on the set current limit).Personally I would prefer to internally let it run all the time and use for MOSFET to switch the output (like for exmaple in Manson NSP3630).But other similar PSUs (e.g. Manson SSP-7080) does it the same way so I guess why not.Control/ergonomoics could be better (in general the FW could be better). For example to set the current limit you have to press "A/V" twice, set the value with the encoder and push enter.The meters have resolution of 10mV and 1mA, the same applies for setting steps. The refresh rate is fast (which I like :-)).There is a thermally (NTC, controlled by the CPU) controlled fan inside. Its hysteresis seems 45C on and 40C off. I would expect/prefer higher and bigger difference - this way the fan can go frequently on and off.Interestingly enough the schema seems to be ready for contious FAN control using PWM (even galvanically isolated) but in my case it is just being switched on (60% duty cycle from 12V) and off.The CV/CC control is standard (analog control loop, CPU just provides the control voltage using PWM). But the CV/CC indication (CV/CC LED control on the front panel) is purelly done in SW by the CPU.The whole power supply is controlled by STM8 micro (12b ADC/DACc, 16b PWM). Internally there is a programming header and the FW is not locked.Attached is also the FW I was able to read from it (would be glad if anybody could decompile or at least disassemble).
Where to buy Milivolt power supply 100mv to 1v+ - Page 1
Forum section: electronics / testgear

author: sn4k3
author_rank: Frequent Contributor
timestamp: April 16, 2018, 05:17:08 pm
content: Hello,I have search under the stores i know and who ship to my country but i can't find any PSU capable of:Type: Variable power supply with good precisionVoltage range: 100mv to 1v, 2v or moreSteps: 10mv would be best but 100mv is ok for the needsCurrent: 10mA to 1A or more would be coolShip from EuropeSome power supplies says 0V to xV but we all know it only start to work at 1V or more, even if they are programmable...There are any easy to get buck converter capable of this?

author: nctnico
author_rank: Super Contributor
timestamp: April 16, 2018, 06:48:05 pm
content: I don't know where you get the impression power supplies start to work from 1V. Any decent bench power supply works from 0V and your 100mV steps aren't a problem at all. Look at GW Instek's GPE-X323 for example for a good value for money PSUhttp://www.gwinstek.com/en-us/products/DC_Power_Supply/Multiple_Channel_DC_Power_Supplies/GPE-X323. This PSU can be set to 10mV / 1mA readback resolution.If money is less of a problem then Keysight has the 36312 or 36313 models to choose from which offer a much higher precision. A cheaper alternative if you are willing to buy used is the Agilent 66311B (and associated models) which gets near source meter territory for very little money. The downside is that these are noisy due to the fan.

author: sn4k3
author_rank: Frequent Contributor
timestamp: April 16, 2018, 08:33:53 pm
content: Quote from: nctnico on April 16, 2018, 06:48:05 pmI know is not all but i have seen some like that, the cheaper ones, i forget to say that power supply is not for me and person is looking for something cheap, not for professional work, so a simple buck or module can do the job. The DPS china modules are capable of that? Or the Korad KA3005P ?

author: nctnico
author_rank: Super Contributor
timestamp: April 16, 2018, 08:39:59 pm
content: I think an Agilent 66311B will be the best precision for money. Switching converters quickly have tens of mV of ripple especially the cheap ones.

author: Synthtech
author_rank: Regular Contributor
timestamp: April 17, 2018, 08:42:16 am
content: Look for a second hand Advantest R6142 or R6144, they should do what you are looking for.

author: xani
author_rank: Frequent Contributor
timestamp: April 17, 2018, 09:51:59 am
content: My Korad can do it and it is basically a bunch of KA3005P glued together.You might want to get KA3305P instead, it is very similar price but gives you 2+1 power suppliels
Take it apart! - Page 1
Forum section: electronics / testgear

author: colorado.rob
author_rank: Frequent Contributor
timestamp: April 11, 2018, 05:11:35 pm
content: The US FTC just re-affirmed that those warranty void stickers are meaningless in the US of A.FTC Staff Warns Companies that it is Illegal to Condition Warranty Coverage on the Use of Specified Parts or Servicesexamples of questionable provisions:This warranty does not apply if this product . . . has had the warranty seal on the  altered, defaced, or removed.

author: Bob Sava
author_rank: Regular Contributor
timestamp: April 11, 2018, 07:19:36 pm
content: Opening a case to just make sure that there are no loose connections, cold solder joints, solder balls or strands of wires should not void the warranty.

author: bd139
author_rank: Super Contributor
timestamp: April 11, 2018, 07:26:32 pm
content: Yep. Same with Sanyo Eneloop charger. If I’d shaken it the solder blim would have dislodged and blown it up.I open everything first.
SSA3032x bandwidth bug at around 1.03, 2.07 and 3.12 GHz? - Page 1
Forum section: electronics / testgear

author: rfspezi
author_rank: Regular Contributor
timestamp: April 11, 2018, 05:40:15 pm
content: I just noticed, that there is something strange going on at 3.12 Ghz on my SSA3032x when switching from a lower BW to 3 MHz BW.Find attached a screenshot comparing the same 3.12 GHz source at 0.1, 1 an 3 MHz BW.Also attached is the initial sweep where i discovered the "bug"?!When you let the source sweep across that frequency range, you see a lot of different variants of distortions - but only when BW is set to 3 MHz.Similar Problem at around 1.03 and 2.07 GHz!

author: rf-loop
author_rank: Super Contributor
timestamp: April 11, 2018, 08:11:05 pm
content: Quote from: rfspezi on April 11, 2018, 05:40:15 pmThe title is wrong or least alternative trumpth. Bug is: You have forced it working out of specs and then you claim with question mark it do not work right.Who have promised there is 3MHz RBW? No one. Just turn off this 3MHz RBW and your selfmade "bug" is repaired.Data sheet:Resolution Bandwidth 1 Hz~1 MHz, in 1-3-10 sequence.If you force it for working outside of specifications only you are responsible how it functions or not.You can hack 2.1GHz model without options to 3.2GHz model with options (but after then cal certificate is not valid) and without opening unspecified 3MHz RBW.

author: rfspezi
author_rank: Regular Contributor
timestamp: April 11, 2018, 08:30:55 pm
content: First:You could have told me that in a normal and kind way.Second:I did formulate the topic as question. Thats what questionmarks at the end of a sentence are used for.Third:Thanks for informing me that 3 MHz BW are not officially supported.Fourth:The true reason why Siglent is selling a lot of devices is their (inofficially supported/wanted) hackability.
HP spectrum analyzer deep dive (bad YIG?) - Page 1
Forum section: electronics / testgear

author: bistromath
author_rank: Newbie
timestamp: April 11, 2018, 06:17:22 am
content: Hey everyone,I might need an expert for this one. Bear with me, there's a lot to go through here.I bought an HP 8593E a few years ago for cheap money, and overall it seems to be working pretty well. There's only one problem, really: the close-in noise is bad. Awful, really. Pictures are worth a thousand words here:So other than that it seems fine.Digging into it, I went ahead and followed the assembly-level service guide and calibrated it, both the self-cals and bandpass filter adjustments. Freq and amplitude calibrations went A-OK, no problems. I verified that both the comb generator and cal outputs are clean and have correct amplitudes. I verified that the 10MHz reference oscillator was clean, but the 321.4MHz first IF and 21.4MHz final IF both showed the problem. This pointed me toward the first LO, so I removed the A3A10 directional coupler's output and sampled the 4.223GHz LO and lo and behold (see what I did there), it was nasty close-in. But why?At this point I checked all the power supplies. The 12V rail has some fuzz on it, but 12V isn't used for analog circuitry so it's not a big deal. +15/-15 look great. So.Following up, I went back and noted that the FM coil diagnostic test had shown a flat line where the assembly-level service guide says there should be a nice ramp:In addition, the occasional "FREQ UNCAL" appears during this test (but never otherwise). At this point, I figured I had something to dig into, and bought a set of schematics (Thanks Artek!). Looking into what we're actually measuring, the FM coil diagnostic is muxing in the actual FM coil voltage -- not the output of the coil driver amplifier, but the voltage on the coil itself. The thing is, the FM coil is only around 1 ohm, so the voltage it sees is around 50mV or so. So it should in fact look like a flat line on the diagnostic screen. What gives?I put a scope on the FM coil amplifier output (before the resistors that make it approximate a current source) and it shows a perfectly fine ramp. In fact, so does the voltage at the FM coil itself -- it's just that it's only around 50mV. I'm chalking this one up to a service manual that doesn't actually reflect the device under test, although I'd be happy to be told differently.Oh, I also followed the service guide's recommendation to try unlocking the LO by removing the counterlock board connections. No change in the output (besides going all drifty on me).So, leaving out about twenty hours of dead ends and false leads, this is where I stand now: the LO is noisy, the FM coil amplifier seems to be fine, and I don't know where to look next. Do I just have a bum YIG? Help!Thanks for reading this far,Nick
Chinese (Reichelt.de) feed-trough BNC terminator - Page 1
Forum section: electronics / testgear

author: mzzj
author_rank: Super Contributor
timestamp: April 06, 2018, 09:45:12 am
content: Was playing along with these and diy cable TDR. These were quite ugly compared to better terminators so I decided to take a look inside:

author: BravoV
author_rank: Super Contributor
timestamp: April 06, 2018, 09:53:43 am
content: Quote from: mzzj on April 06, 2018, 09:45:12 amClick to enlarge photo.Indeed, even the Banggood or Aliexpress cheapos are better in terms of construction, reviewed ->HERE

author: mzzj
author_rank: Super Contributor
timestamp: April 06, 2018, 10:19:00 am
content: This homebrew was couple of orders better:

author: ebastler
author_rank: Super Contributor
timestamp: April 06, 2018, 11:29:17 am
content: Quote from: mzzj on April 06, 2018, 09:45:12 amThat was a rather thorough "look inside".Thanks for the photo!

author: paschulke2
author_rank: Contributor
timestamp: April 06, 2018, 11:55:46 am
content: I once was tempted to buy this terminator from Reichelt because it is much cheaper than a Pomona 4119-50. I did not buy it because i did not like its length (it's an invitation to break the BNC jacks of your scope) and because I thought i was too cheap. Seems I was right …Now if someone could please cut open a Pomona 4119-50 …

author: tkamiya
author_rank: Super Contributor
timestamp: April 08, 2018, 02:27:19 pm
content: Wow.... the original picture is not even a "feed through" as there is no connection between center pins. I guess that short wire is a "radiator" and pin on the other side is the "receiver?"Similar story. I took apart a cheapo Chinese made 50 ohm terminator. Ground side was not firmly attached anywhere but it was a "press fit" by folding the wire back and shoving it on a tube. Amazingly, it worked ok for 1.5Ghz.

author: Twoflower
author_rank: Frequent Contributor
timestamp: April 08, 2018, 02:56:22 pm
content: That missing feed-through came up to my mind as well. But if you look closely there is a bluish wire running left of the resistor. It ends in the middle of nowhere about in the middle of the resistor. So I assume the cut was cutting also the wire and the center connector at the lower connector.

author: Ringmodulator
author_rank: Regular Contributor
timestamp: April 10, 2018, 06:07:37 pm
content: I had also bought one of those from reichelt.de some years ago. If I remember correct, they were even specced for 1GHz bach thenAs I checked this one, it turned out to be good up to maybe 30MHz.I have built way cheaper ones with a BNC plug and socket like on the picture above from BravoV.The caveat with those is the low power rating for the SMD resistor(s).
Jittery Sine Wave on BK 4017A - Page 1
Forum section: electronics / testgear

author: ptlud
author_rank: Newbie
timestamp: April 13, 2018, 03:19:37 pm
content: I recently purchased a used BK 4017A function generator. I hooked it up to my oscilloscope and found that the sine wave (+square and triangle) are jittery in the time domain. This only occurs for frequencies less than 1 kHz. Every frequency above 1 kHz is rock solid. I hooked the scope probe right to the BNC connector while the cover was off.I took the function generator to work and used a Tektronix 210 digital scope and found the same issue. Also, I De-Oxit'd all the pots and push-button switches, with no improvement.Is this unusual? Is it fixable?Thanks!
Xeltek adapter pinouts - Page 1
Forum section: electronics / testgear

author: JeffreyLatter
author_rank: Contributor
timestamp: April 09, 2018, 03:05:26 pm
content: Hi Guys,I have the Xeltek superpro 3000u with PEP3000 100pin driver, but I'm working on a project where I need to readout a PLCC52 IC - Before I go out and buy the Xeltek S415T adapter, do any of you guys, know the pinout of this adapter? (Then I could route one myself and let the cnc create one)BrJeffrey