hybridfree/eevblog-posts huggingface dataset:
Serial decode inaccurate on DS1074Z when zoomed out - Page 1
Forum section: electronics / testgear

author: tom66
author_rank: Super Contributor
timestamp: March 14, 2014, 10:23:43 pm
content: It seems DS1074Z will process I2C/RS232 accurately when zoomed in, but not when zoomed out. This appears to be down to the Dig.Sample rate in the options menu, I am guessing it is aliasing its internal sampling (separate from normal processing) when zoomed out. But, the option is greyed out. Any way this can be changed?(Note the "?" on the bus when zoomed out, also, the data bits are usually corrupted on longer transfers.)

author: Rigby
author_rank: Super Contributor
timestamp: March 14, 2014, 10:33:40 pm
content: This scope decodes from screen memory. I'm pretty sure that the full memory is only available for reading when the scope's run/stop button is red (stopped.) That's certainly true for SCPI, so I imagine there is an architectural reason.If your scope is stopped for the screenshots, then this is probably just a limitation of the scopes. Now that I type that, I seem to recall reading that it's a common thing among Rigols - inability to decode from anything but the screen.Someone else will likely pipe up and correct/confirm what I've written.

author: KD0RC
author_rank: Regular Contributor
timestamp: March 14, 2014, 10:42:14 pm
content: Hi Tom66, I have an Agilent 2000x series, and it does exactly the same thing. When I go to 320 ms/div, I get red blocks that do not decode mixed in with blue blocks that do. I think it is more to do with the sweep speed, and not so much the sample rate. Mine goes down to 50 KSa/s at 210 ms/div, but it continues to decode until I get to 320 (still at 50 KSa/s).Anyone else know if my hypothesis is correct?

author: tautech
author_rank: Super Contributor
timestamp: March 14, 2014, 10:43:05 pm
content: Try adjusting Horizontal position and Timebase to get all of the packet of data on screen. Then single shot. Then zoom with Timebase to area of interest.

author: tom66
author_rank: Super Contributor
timestamp: March 14, 2014, 10:45:29 pm
content: I can do that, and it'll decode fine when zoomed in - I guess it's just a limitation.It would also explain why things like risetime/frequency cannot be measured when zoomed out.

author: Mark_O
author_rank: Frequent Contributor
timestamp: March 15, 2014, 11:01:29 am
content: Quote from: tom66 on March 14, 2014, 10:45:29 pmRight. Measurements are made from data in Display memory, not Sample memory.
Tektronix DM44 compatibility - Page 1
Forum section: electronics / testgear

author: Analogdevice
author_rank: Contributor
timestamp: March 15, 2014, 10:56:24 am
content: Hello,is Tektronix DM44 digital multimeter compatible with 463 oscilloscope?Thank you.

author: PaulAm
author_rank: Frequent Contributor
timestamp: March 15, 2014, 02:43:44 pm
content: At least on a 465 you can't tack on a dm44 without other changes in the scope, particularly the sweep board. I imagine the 463 would be similar.
A proper way to measure resistance, the wheatstone bridge - Page 1
Forum section: electronics / testgear

author: KJDS
author_rank: Super Contributor
timestamp: March 12, 2014, 10:05:33 pm
content: I picked up this delightful old bridge today.Checked it with a 7.02kohm resistor and it was spot on. It's out on low resistance values, probably the switches need a good clean.Does anyone still use something like this, or have similar?

author: David Hess
author_rank: Super Contributor
timestamp: March 12, 2014, 11:10:13 pm
content: I have a couple of ESI 250DA impedance bridges which are still as good as my best precision resistors.

author: Dave Turner
author_rank: Frequent Contributor
timestamp: March 13, 2014, 12:25:36 am
content: My first experience of a Wheatstone bridge involved a metre long resistance wire, known resistance, sensitive meter and a knife edge connector - real old school and quite accurate.

author: casinada
author_rank: Frequent Contributor
timestamp: March 13, 2014, 06:13:21 am
content: That was probably a potentiometer

author: staxquad
author_rank: Frequent Contributor
timestamp: March 13, 2014, 11:21:22 pm
content: I like the old stuff, had workmanship and heft.Have an old Harrison ZM-4 B/U resistance bridge, but haven't used it much, would need to bother installing a proper battery to use itranges below 10 ohms to 1 Meg in 6 rangescan do Varley loop test, Hilborn loop test, Murray loop test, use as a resistance boxhave two of these Shallcross 673-D milliohmeters, including their hefty kelvin clamps and gun, would use them more but I prefer the GEmeasures resistance from 0.0001 to 5 ohms in 5 rangesthe GE portable (ya right) double bridgemeasures resistance from 0.0001 to 22 ohms in 8 rangeswas last calibrated in 1978, and is still spot on, it measures both my Shalltronix .0025 ohm test standards as .0025 ohms, not a hair more or less on the dial, so all 3 in accordance (multiply the reading with the range, so .050 x .05 = .0025)my LCR meter was also in accordance (the 2 test standards in series), although the GE has an extra digit

author: SeanB
author_rank: Super Contributor
timestamp: March 14, 2014, 07:36:17 pm
content: I have a Kokogawa one that is quite nice, though I rarely use it, simply as a DVM is so convenient. It is nice thuogh in that it will do low resistance quite well, and can measure cable length very well.
Rigol DS2202A-S  vs Pico USB 200MHZ Scopes - Page 1
Forum section: electronics / testgear

author: Lynntank
author_rank: Newbie
timestamp: March 16, 2014, 02:23:11 am
content: I have veiwed the teardown on a Rigol but I like the DS2202A or the DS22002a-S. Dont know what the S option is. I have seen pictures of screens that have signals taken with USB scopes and there seems to be more options with them. I just dont know of the build quality or durability of the USB scopes. What is more forgiving if connected to circuit incorrectly? Suggestions?

author: echen1024
author_rank: Super Contributor
timestamp: March 16, 2014, 03:28:13 am
content: "S" is the function generator option. I would DEFINITELY go for the Rigol. Standalone is easier to use, and the good USB scopes are expensive as hell, and the Chinese ones don't come close to a Rigol.

author: David Hess
author_rank: Super Contributor
timestamp: March 16, 2014, 04:41:41 am
content: The Rigol specification for overload looks better but I doubt the specifications of either oscilloscope can be trusted. There is more to go wrong with the USB oscilloscope because the USB port is not galvanically isolated. Neither would be repairable after overload in the sense of an old oscilloscope which has service documentation.I would go with the Rigol simply because it is a standalone instrument which will take less space.

author: alex.forencich
author_rank: Frequent Contributor
timestamp: March 17, 2014, 05:41:47 am
content: A standalone scope that boots up quickly is incredibly convenient. Standalone scopes also tend to have knobs and buttons, which is far more user-friendly than clicking buttons with a mouse. Also, they tend to be significantly more responsive as the USB connection to the computer can act as a bottleneck and add latency. The PC side software for USB scopes also tends to be a bit of an afterthought, which is unfortunate.
HP 3852A EPROMs or EPROM images? - Page 1
Forum section: electronics / testgear

author: AndersG
author_rank: Contributor
timestamp: January 30, 2014, 02:01:44 pm
content: I bougt a HP 44788 GPIB controller for my 3852A, but it needs at least FW 3.5 and mine is 1.2. Does anyone have a 3852A with 3.5 or better FW? Anyone brave and kind enough to copy the ROMs? 6 pcs 27256, socketed. Or copy to a file?

author: AndersG
author_rank: Contributor
timestamp: March 13, 2014, 06:30:42 am
content: Just FYI: I got an upgrade kit from Agilent. A copy of the ROMs and instructions are available athttp://www.dalton.ax/hp3852a/
Looking for information on function generator Playtronic XR2206 and WOB2206 - Page 1
Forum section: electronics / testgear

author: theelectronicegg.com
author_rank: Newbie
timestamp: March 12, 2014, 08:02:06 pm
content: i am looking for informations about playtronic.i am watching an Playtronic XR2206 and an Playtronic WOB2206 on eBay.these are function generators, that were sold as kits in the past.they are sold as "as is" and may not work...no problem, i could learn something while repairing!But i can't find any schematics, manuals or specs...The model number suggests its using an xr2206 Monolithic Function Generator IC.So i am looking for:a) schematicsb) manualsc) spec sheetsd) experience with these function generators or this manufacturerthanks

author: rdl
author_rank: Super Contributor
timestamp: March 12, 2014, 08:18:07 pm
content: As a start, do a Google search for Exar TAN-005. This was a document they published which describes how to build a "High Quality Function Generator" using the XR2206. It's likely the kit was designed using this document as a guide.

author: schwarz-brot
author_rank: Regular Contributor
timestamp: March 12, 2014, 10:00:41 pm
content: I would additionally suggest starting with the datasheet of the xr2206. It gives you complete testcircuits for nearly anything these ICs can do and explains which calculations have to be made. It is a very nice datasheet for beginners as it gives much advice in an understandable way.It was the very first project I did from start to end to build a little xr2206 function generator just from the information in the datasheet and my design goals. Nearly as simple as a LM317/337 Power supply...have fun!
How about an LCR review? - Page 1
Forum section: electronics / testgear

author: Axtman
author_rank: Regular Contributor
timestamp: March 11, 2014, 06:30:18 pm
content: Hey Dave,How about a product comparison and tear down review of different LCR meters?Thanks!

author: KedasProbe
author_rank: Frequent Contributor
timestamp: March 12, 2014, 02:19:28 pm
content: Would be a good opportunity to explain component tests. And maybe improve a simulation example with ideal components and check it.
Bandpass sweeps with HP 8903 - Page 1
Forum section: electronics / testgear

author: nickm
author_rank: Regular Contributor
timestamp: March 14, 2014, 03:57:45 am
content: I found out today that there are a whole bunch of special functions for the HP 8903 listed in the service manual which aren't listed in the normal operating manual. The most interesting one to me is the 44.3 which uses the bandpass filter instead of the notch filter. What I'd like to do is sweep the bandpass filter without the generator to measure the noise floor of stuff the same way that you can with the Audio Precision analyzers. 54.X sets the course frequency of the notch filter from 0-255 but you have to look up in a table what each value corresponds to. The manual says see Service Sheet 3 for more information, but I was not able to find this. There is also a 53.X that affects the notch frequency but again you need the Service Sheet 3 to find out exactly what it does. Does anybody have any experience with this? Is it possible to do bandpass sweeps?
Hantek PPS2116a PC connectivity problem - Page 1
Forum section: electronics / testgear

author: fqahmad66
author_rank: Regular Contributor
timestamp: March 11, 2014, 09:42:51 am
content: Bought subject supply due to very low budget, space constraint and needed 5A. So far seems to be working OK. Checked overshoot with soft start...none. But hard start has a lot. Now comming to problem..cannot communicate with PC. latest drivers for CP2101 are installed..shows COM4 in device manager (XP SP3). GUI from Hantek website does not work. It shows 'device connected' but in white lettering instead of red (should be red as shown on various screenshoots on net). All other buttons are greyed out. Tried reinstalling with no success. Any ideas?RegardsF
usb50 oscilloscope - Page 1
Forum section: electronics / testgear

author: R_G_B_
author_rank: Frequent Contributor
timestamp: March 13, 2014, 01:29:00 pm
content: Has anyone else seen this product if so how does it compare with other portable DSO deviceshttp://m.youtube.com/watch%3Fv%3Dj1DfiEW6RV8&cd=1&ved=0CCkQtwIwAA&usg=AFQjCNHGRswIGYyerEhGLqeia2nW0gOE6A

author: R_G_B_
author_rank: Frequent Contributor
timestamp: March 13, 2014, 01:30:31 pm
content: Correct link

author: casinada
author_rank: Frequent Contributor
timestamp: March 13, 2014, 03:52:10 pm
content: That company went out of business.....
CircuitCellar - Evaluating Oscilloscopes - Page 1
Forum section: electronics / testgear

author: Kappes Buur
author_rank: Regular Contributor
timestamp: March 11, 2014, 12:57:21 am
content: Circuit Cellarran a nice 4 part series about Evaluating Oscilloscopes.

author: nctnico
author_rank: Super Contributor
timestamp: March 11, 2014, 01:36:48 am
content: The author bought a USB scope and made a USB keyboard emulator with rotary encoders to control it!More nonsense:If you end up needing DC 50 termination, you can buy “feed-through” terminators for about $15, which operate at up to 1-GHz bandwidth. You simply add those to the front of your oscilloscope to get 50-? terminated inputs.The author also doesn't get that the 16 bit 'resolution' is coming from oversampling an 8 bit ADC. That is a bit optimistic to say the least. All in all it's a Picoscope advertorial. Nothing more.

author: EEVblog
author_rank: Unknown
timestamp: March 11, 2014, 03:00:12 am
content: Quote from: nctnico on March 11, 2014, 01:36:48 amOh wow, that's funny.QuoteThen goes and builds that knob box:

author: FrankenPC
author_rank: Unknown
timestamp: March 11, 2014, 03:29:04 am
content: What could possibly go wrong?

author: Mark_O
author_rank: Frequent Contributor
timestamp: March 11, 2014, 03:39:47 am
content: Quote from: nctnico on March 11, 2014, 01:36:48 amWell, I think it does cover some basics, and scope choices, that go beyond Picoscopes. It could be useful and educational reading for newbies, if they can overlook the bias toward USB units that completely ignores price/value.Besides, Picoscopes are cheap! The base version of the 4-channel unit he has is less than $3,300.Sample-rate is impressive though, at 5 GSa/s. But at that price, with no screen, no controls, etc. I would certainly hope so.

author: Carrington
author_rank: Super Contributor
timestamp: March 11, 2014, 11:11:27 am
content: Quote from: nctnico on March 11, 2014, 01:36:48 amYep! More than evident.Quotehttps://github.com/colinoflynn/scope-bw-exampleYes, I played with this script, it looks interesting, but I can't set the input signal rise time.

author: HKJ
author_rank: Super Contributor
timestamp: March 11, 2014, 01:01:20 pm
content: Quote from: nctnico on March 11, 2014, 01:36:48 amPicoscopes has scopes with ADC's that has more than 8 bits (12 & 16 bit depending on model) and in their software it is also possible to select oversampling for up to 4 bits extra.

author: nctnico
author_rank: Super Contributor
timestamp: March 11, 2014, 01:14:16 pm
content: Now closely investigate the requirements formeaningfuloversampling. My Tektronix oscilloscope also has oversampling to get to 11 bit but it is very easy to get false results. There is much more to oversampling than meets the eye which is why they sell ADCs with many different bit lenghts instead of one 10GHz single bit ADC. From my own experience with Picoscopes I know you can get funny results when oversampling is enabled.

author: Yago
author_rank: Frequent Contributor
timestamp: March 11, 2014, 02:50:17 pm
content: Quote from: EEVblog on March 11, 2014, 03:00:12 amOi, who are you callin' a knob box ?
Question about software for the Agilent U125x series - Page 1
Forum section: electronics / testgear

author: achaios
author_rank: Newbie
timestamp: March 10, 2014, 07:58:05 pm
content: After a long delay, my Agilent U1252B is on its way. Can anyone tell me if the software for that meter will run on Linux, or is it for PCs only?BTW, I went with Agilent just because some of my best years were spent programming on HP computers. I have nothing against other manufacturers, and may choose a different brand when I eventually get a bench DMM. When I get the bench DMM, I will want that really high impedance capability, after seeing Dave's video. If you know of one I ought to look at, let me know. I would want it to be as far under $1K as possible, new.Thanks,-- Tom

author: echen1024
author_rank: Super Contributor
timestamp: March 11, 2014, 12:53:53 am
content: I would try WINE.

author: mjkuwp
author_rank: Unknown
timestamp: March 11, 2014, 03:16:56 am
content: I have the optional bluetooth and use the Android software. It works pretty well. The Windows software might be more flexible but I find the wireless so much more convenient.

author: achaios
author_rank: Newbie
timestamp: March 11, 2014, 11:28:21 am
content: Quote from: echen1024 on March 11, 2014, 12:53:53 amD'oh! I completely forgot about WINE. I'm so used to not running Windows except when I have to that I didn't think about it.Thanks,-- Tom

author: SeanB
author_rank: Super Contributor
timestamp: March 11, 2014, 11:54:29 am
content: If it does not work under WINE then Virtualbox with the addon pack works better than an OEM windows install. You just need a valid key and install it.
OWON EDS102CV 100M VGA english software - Page 1
Forum section: electronics / testgear

author: iptex
author_rank: Newbie
timestamp: January 28, 2014, 11:16:50 am
content: Hello!I just bought an oscilloscope OWON EDS102CV 100M VGA (analog for EU SDS7102). There is only one problem - oscilloscope menu only in Chinese. Yes, i can work with it but it's hard. Maybe someone has an English firmware for this oscilloscope or technique how to change the Chinese language menu to English version.

author: phil
author_rank: Regular Contributor
timestamp: January 28, 2014, 01:47:23 pm
content: I have the SDS7102. I don't know if your soft buttons are labled english or chinese, so I will try to describe the procedure as good as I can.To change the language (if the firmware is the same between both scopes):- Press "utility" (3x3 soft buttons between the multi purpose knob and run/stop control; left column, middle button)- Press "H1" (first horizontal button)- A menu appears on the left hand side of the screen. Use the multi purpose knob to select the first function- Press "H2" (second horizontal button) to open the language menuPhil

author: iptex
author_rank: Newbie
timestamp: January 28, 2014, 01:58:26 pm
content: Thank you for reply Phil! But i have no item with English menu in my version. I need information or firmware how to do from my China version EDS102CV good EU version (SDS7102). I think i need hack it.

author: echen1024
author_rank: Super Contributor
timestamp: January 28, 2014, 03:48:23 pm
content: Try putting the SDS7102 firmware on?

author: iptex
author_rank: Newbie
timestamp: January 28, 2014, 05:26:42 pm
content: I cannot update from SDS software as after start i have - .you model not in list. May be there are specials ways how to update it via USB flash..

author: phil
author_rank: Regular Contributor
timestamp: January 28, 2014, 05:34:02 pm
content: I think you will have a hard time if the normal SDS7102 firmware update isn't compatible. Most people here will have the SDS model. I didn't even know that there was a chinese version of it at all.And I doubt that anyone would waste time to take a closer look at the firmware as there are no options to activate or other benefits to gain.I'm afraid you are on your own with that one, sorry.Phil

author: tinhead
author_rank: Super Contributor
timestamp: January 28, 2014, 06:10:01 pm
content: oh well, maybe there is a way. When you look exactly, here is the way how to extract firmwarehttps://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg337436/#msg337436as i understood one cab "compile" own version, one which will accept your model as well

author: KindleFlame
author_rank: Newbie
timestamp: March 10, 2014, 02:08:53 pm
content: There's a chinese version that's specifically designed for the chinese market that's basically the exact same scope, but around 80 dollars cheaper.If you can read chinese. Most owon scopes on taobao are EDS instead of SDS.The scummy thing is that they try to sell it as an "upgrade", instead of the sidegrade that it is.However, if you read russian, this guy's managed to do it.https://www.eevblog.com/forum/testgear/review-of-owon-sds7102/msg337430/#msg337430
UNI-T UT61E and Victor VC8145 long-term accuracy as well as UT10 - Page 1
Forum section: electronics / testgear

author: T4P
author_rank: Super Contributor
timestamp: May 17, 2013, 09:09:18 am
content: I don't have a volt reference but i still did it anyway, compared against a mint U1273AXNow i don't understand why some people think the 18~28C UT61E operation band is a problem anymore ... They have been stored way outside it's specs for a year now and what's the result? Within 10 counts. Yeah you heard that rightAnd again those people who think it will be more inaccuratei have a twin bought on different date and it's accuracy is roughly the sameInaccurate, eh?

author: mcinque
author_rank: Unknown
timestamp: March 09, 2014, 08:51:35 pm
content: Thank you, your test results are very useful and accurate.At this point I really don't understand what about the voltage drift that some users reported.

author: Lightages
author_rank: Unknown
timestamp: March 09, 2014, 09:03:52 pm
content: I am glad that you have good performing equipment. Not everyone had stable UT61Es and that is a fact. It is like everything else, you sometimes get lucky and sometimes not.
Measuring Thermocouple resistance - Page 1
Forum section: electronics / testgear

author: neslekkim
author_rank: Super Contributor
timestamp: March 10, 2014, 12:16:53 pm
content: I have been trying to measure resistance on some soldertips with built in heater and thermocouple (JBC 245 and 210 tips), but since an thermocouple also gives some voltage, it seems like it's not that easy to measure this correct?I have been using Fluke 87-v, Fluke 289 and Agilent 34461ABoth fluke's are just rolling the numbers, impossible to take a read, but the Agilent it's easier to get something, but not steady always.Someone said that the Agilent U1272A have an smart ohm function which can measure even if you have voltage..How can i do this?, Do I need 4wire probes for my Agilent?, and is the Flukes unusable for this?(I'm also considering getting an DE5000 LCR meter, does those meters understand this type of resistance?)

author: macboy
author_rank: Super Contributor
timestamp: March 10, 2014, 12:32:39 pm
content: You need a meter that can measure "offset compensated" resistance. This is intended to compensate for the thermoelectric/thermocouple effects of the dissimilar metals used in the the wires, connectors, solder joints, etc. in all the connections between the meter and the device under test, but it will work fine for the thermocouple effect of a ... thermocouple.A question that needs to be asked though, is why do you need to know the resistance of the thermocouple?

author: neslekkim
author_rank: Super Contributor
timestamp: March 10, 2014, 01:44:48 pm
content: Quote from: macboy on March 10, 2014, 12:32:39 pmTrying to find out where the thermocouple is, and where the heater isOn the C245 tips, there are bigger difference in the resistance so it's kinda easier to see it, but on C210 there are very small resistance on the heater, so it was difficult to find out what is what..But since my meters behaved so strange I got a little caught up with this..Can't any of my meters handle this?, do I need to buy an "cheap" agilent handheld to get this to work?

author: ruffy91
author_rank: Regular Contributor
timestamp: March 10, 2014, 03:34:49 pm
content: You could just measure the Voltage on the 4 leads to find out where the thermocouple is, the heating element will read 0V, the thermocouple a few mV if you heat it with a lighter.

author: cyr
author_rank: Frequent Contributor
timestamp: March 10, 2014, 05:37:08 pm
content: You should be able to do offset compensation manually on any DMM with 4-wire ohms.

author: neslekkim
author_rank: Super Contributor
timestamp: March 10, 2014, 11:32:25 pm
content: So, then I have to find some decent kelvin probes?
Capacitor tester? - Page 1
Forum section: electronics / testgear

author: Axtman
author_rank: Regular Contributor
timestamp: March 09, 2014, 06:32:19 pm
content: I bought a huge bad of "newer" electrolytic capacitors. Some of the caps were removed from boards and some are unused. I would like to test these caps before using them. I don't want to replace a bad cap with a bad cap. What capacitor tester do you recommend?

author: mariush
author_rank: Super Contributor
timestamp: March 09, 2014, 07:01:05 pm
content: A good LCR meter with ESR measurement, or a cheaper ESR meter... Atlas ESR70 , ESR-Micro -but only after talking to manufacturer ( user RusMike on badcaps.net forums) - , other more diy esr meters...A multimeter will only measure capacitance, which is often not good enough to determine if a capacitor is good or not.

author: Dave Turner
author_rank: Frequent Contributor
timestamp: March 09, 2014, 07:03:38 pm
content: Do a search on this forum, there's a number of threads about this topic.

author: uwezi
author_rank: Unknown
timestamp: March 09, 2014, 08:08:00 pm
content: The $20 transistor tester which is discussed here as well, will give you at least a go/no-go. It is quite a good universal tool.https://www.eevblog.com/forum/testgear/$20-esr-lcr-transistor-npn-pnp-mosfet-meter/

author: PA4TIM
author_rank: Super Contributor
timestamp: March 09, 2014, 08:18:23 pm
content: Decent LCR meter that also measures D.A DC leakage tester-reformer. extreme easy to build
Hackers! any solution to update Siglent SDS1072CML to 100MHz? - Page 1
Forum section: electronics / testgear

author: Terry
author_rank: Contributor
timestamp: March 08, 2014, 03:46:23 am
content: i purchased a 1072cml at a nice pricethe seller told me it can be updated to 100Mhz, but he didnt tell me how???http://www.aliexpress.com/store/product/BEST-PRICE-New-Siglent-70MHz-SDS1072CML-Digital-Storage-Oscilloscope-2-channels-7-display-2Mpts-long-memory/521168_1352141711.htmlanybody knows?really appreciate it!

author: Mark_O
author_rank: Frequent Contributor
timestamp: March 09, 2014, 03:38:09 am
content: Quote from: Terry on March 08, 2014, 03:46:23 amWhy not just ask the Seller?He's the one who made the claim.
[DP832] - Problem after change the analog board .... - Page 1
Forum section: electronics / testgear

author: stormbr
author_rank: Regular Contributor
timestamp: March 09, 2014, 01:02:22 am
content: Hi folks,My dp832 is the first revision (fw 1.03) and did have a old analog board with the temperature issue, so i decide "fix" it alone. The rigol send to me a new board revision 2.1 equal the review of Dave, but i can't recalibrate the power supply.1-) The power supply show the warning: "analog board self-test fails".2-) Channel 2 is locked on 33.61 volts.3-) Channel 3 is locked on 0.004 volts.4-) Channel 1 not calibrated.I read on tutorial to recalibrate, that need a short-circuit the output ? I not understand this step (pics attached).- I too update to firmware version 1.09, i follow the guide of rigol and updated the firmware, bootloader and the analog board, no errors.- I install the old board again, but the same problem persist.- My power supply is hacked, but i can't uninstall the keys with a scpi command, this method not work on dp832.Thanks for any help.

author: Rigby
author_rank: Super Contributor
timestamp: March 09, 2014, 01:08:12 am
content: those sense instructions do not apply to your supply. read the top sentence in that image carefully, paying attention to the models listed. the dp832 is not listed, so those steps do not apply.

author: stormbr
author_rank: Regular Contributor
timestamp: March 09, 2014, 01:16:30 am
content: Thanks, i did not do this step, but I got doubts.I think that lost a source.
Question about trigger setup on Rigol DS/MSO4000 - Page 1
Forum section: electronics / testgear

author: Sailor
author_rank: Regular Contributor
timestamp: March 08, 2014, 03:42:22 am
content: I normally use a Tektronix MSO4034, but I've got my hands on a Rigol MSO4014 for a couple of days (thinking about buying one). It's a bit of a learning curve switching from the Tek, so I have a quick question: On the Tek I can configure it so that the trigger event is at some defined point of the display (default is 10%) i.e. 10% of the capture memory has pre-trigger info, and the remaining 90% of the memory is post-trigger info. But on the Rigol it seems that the trigger point is fixed at the 50% point of memory, or at least I can't find a way of altering it.Is there something that I am missing???Thanks,

author: Cdngreybeard
author_rank: Contributor
timestamp: March 08, 2014, 04:36:57 am
content: If you're referring to the Horizontal reference point, then yes by default it is set to the 50% point. It can also be changed to reference the trigger point, or it can be set to a user defined reference point. This adjustment is accessed from the Horizontal menu function -> HorRef.Hope that helps.

author: Sailor
author_rank: Regular Contributor
timestamp: March 08, 2014, 06:55:30 am
content: Thanks for replying, but that's not what I'm after. As it says in the User Manual, that HorRef is the point about which the display expands when adjusting Horizontal Scale.A little while later...As it turns out, the position of the trigger point is adjusted by using the Horizontal Position knob, BUT Delayed Sweep must be OFF in order to make that adjustment. If Delayed Sweep is ON, the Horizontal Position knob only moves the position of the delayed window. So you must turn Delayed Sweep OFF, set the trigger position, then turn Delayed Sweep ON and you're good to go.Again, thanks for the reply.
Fluke 23 multimeter troubleshooting - Page 1
Forum section: electronics / testgear

author: mrflibble
author_rank: Super Contributor
timestamp: March 08, 2014, 01:59:11 pm
content: I've got a Fluke 23 here that's a wee bit wonky. As in, doesn't work properly at all. And of course no information on how it went *poof*. That would be too easy.The behavior is roughly the same on all ranges. It looks like it just keeps integrating until it goes out of range. So when I change from Ohm to 300 mV or V==, you can see it slowly integrating towards the negative supply. Until it goes out of range and then it's just OL on the display.The speed with which it integrates toward minus overload is different for probes shorted vs open. With probes shorted it integrates faster and goes into overload faster.I did a visual inspection and I cannot see anything dodgy. All components look fine. Measured movs ... no shorts. Fuses are also fine. No dodgy caps (I think). But who the hell cares about components thatlooksfine if it doesn't work.Any hints on how to troubleshoot this thing? Service manual? I amhopingthat this is a well known failure mode that one of the many Fluke fans on here know how to fix. And I'm also hoping it doesn't involve replacing the Fluke 683052 asic.Thanks in advance for any help.

author: oldway
author_rank: Super Contributor
timestamp: March 08, 2014, 05:11:07 pm
content: You can use a serie 70 service manual, they are very close.http://www.transmille.net/ProCal/Procedure%20Library/Fluke%20Digital%20Multimeter%2073%20%5B1.10%5D/Technical%20Data/Fluke%2070%20Series%20%28PN731034%20January%201984%20Rev%201%2005-89%29%20%20Service%20Manual.pdfFirst, check R1 (1K), it's a fuse resistor.

author: retiredcaps
author_rank: Super Contributor
timestamp: March 08, 2014, 05:45:17 pm
content: The usual suspects are all the input protection components like the fusible resistor (R1), thermistor (RT1), and varistors (RV1 and RV2).A good IPA cleaning of the pcb doesn't hurt either after replacing any bad components.
Fluke 87 (original) series - Page 1
Forum section: electronics / testgear

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: March 04, 2014, 04:33:21 am
content: Have 2 of these, and noticed the later serial numbered meter has slightly smaller digits on the display, a brighter, more evenly lit backlight, and n the older s/n meter has extra symbol on the left side of the display, like a sun, or lit lamp. It does not seem to ever come on. Anyone know what that is?

author: retiredcaps
author_rank: Super Contributor
timestamp: March 04, 2014, 05:27:48 am
content: My guess is that it is the backlight indicator, but they never implemented it?

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: March 04, 2014, 05:41:32 pm
content: I guess they saw the light...

author: N2IXK
author_rank: Frequent Contributor
timestamp: March 04, 2014, 08:06:04 pm
content: Wonder who thought that a separate indicator was needed to tell you that the backlight was on?

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: March 05, 2014, 05:21:50 am
content: Someone looking busy while trying to keep their job???

author: GreyWoolfe
author_rank: Unknown
timestamp: March 05, 2014, 01:23:06 pm
content: Of course you need an indicator. Light on verses light off is not quantifiable enough.

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: March 05, 2014, 11:31:29 pm
content: Speaking of the light... anyone ever upgrade the 87 to a white LED like the V

author: retiredcaps
author_rank: Super Contributor
timestamp: March 06, 2014, 12:54:08 am
content: Quote from: SoundTech-LG on March 05, 2014, 11:31:29 pmModemhead has. Notice the larger lcd font on the original 87 versus the 85.http://mrmodemhead.com/blog/wp-content/gallery/f83_00-2/F83_008.JPGI prefer the larger and upright font.

author: calexanian
author_rank: Super Contributor
timestamp: March 06, 2014, 05:51:44 am
content: Just looked at my 87. It is identical to your display ACCEPT where yours shows the backlight icon, mine is blank. hmmmmmmmm.......

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: March 06, 2014, 09:27:21 pm
content: So, it sounds as if the entire LCD Display needs to be changed, to get the white LED's, not just swapping of LED's??

author: Excavatoree
author_rank: Frequent Contributor
timestamp: March 06, 2014, 09:33:10 pm
content: Quote from: SoundTech-LG on March 06, 2014, 09:27:21 pmNo, the backlight is a separate module that can be changed separately.The LCD can be changed to get the different digits, see the link retiredcaps posted for a picture of the two types.http://mrmodemhead.com/blog/wp-content/gallery/f83_00-2/F83_008.JPGDon't quote me until it's verified, but I believe the right LCD is for the 87-III, which is interchangeable.
Keithley 173A multimeter? - Page 1
Forum section: electronics / testgear

author: Axtman
author_rank: Regular Contributor
timestamp: March 06, 2014, 06:12:10 pm
content: I have a chance to buy a Keithley 173A bench multimeter for less than $50 USD. I am intrigued by the 4 wire resistance measurement capability. Is this a good meter or should I save my pennies for something more modern? Do people use bench meters anymore or does everyone just use a handheld multimeter? Thanks!
DG4000 windowed burst? - Page 1
Forum section: electronics / testgear

author: Rory
author_rank: Frequent Contributor
timestamp: February 28, 2014, 09:17:55 pm
content: Short of creating an arbitrary waveform, is there a way to generate a triggered and/or delayed repetitive windowed burst, similar to AM of a sine wave with a window function? It should be like the N_Cycle burst, except that the duration is defined in units time, not cycles.I have been able to create a repetitive pattern with the AM mod feature, using Arb as the mod source with a built-in waveform window function with a frequency of 1/(window period). However, I need the ability to generate a single windowed burst where the generator primary wave frequency is independent of the window frequency.

author: Rory
author_rank: Frequent Contributor
timestamp: March 05, 2014, 04:39:09 am
content: Moving this question to an already-existing thread, hopefully someone will answer.

author: KedasProbe
author_rank: Frequent Contributor
timestamp: March 05, 2014, 10:04:01 am
content: Don' t you want "gated burst" ? (control the gate with the other channel)

author: Rory
author_rank: Frequent Contributor
timestamp: March 05, 2014, 09:02:12 pm
content: Quote from: KedasProbe on March 05, 2014, 10:04:01 amNot sure how to do that with windowing feature. Gated infers rectangular window. I need to apply a window function like gaussian or blackman to shape the burst for processing.Can you describe how to control the gate with the other channel, in terms of DG4000 key presses or sequence?

author: KedasProbe
author_rank: Frequent Contributor
timestamp: March 06, 2014, 09:08:46 am
content: Yes, in that case it's only a rectangular window (start/stop), although you have freedom to put in there what you want and start and stop when you want, except AM I don't know of any other method.Quote from: Rory on March 05, 2014, 09:02:12 pmJust connect a cable from that channel to the external input.

author: Rory
author_rank: Frequent Contributor
timestamp: March 06, 2014, 05:23:43 pm
content: Ok, was able to produce what I wanted, did as you suggested and set up ch2 with an Arb waveform with built-in window function, 10mS period, N-cycle burst mode, 1 cycle, 100mS period fed the output of ch2 to the rear modulation jack for ch1. On ch1, set up a sine waveform 10 Khz, AM modulation.Had to adjust ch2 level ( and offset as well as ch1 modulation depth (103%) to eliminate residual carrier outside of the envelope. There are definitely some parameters that need calibrating in this mode.Thanks for the help!
OVP & OCP - Page 1
Forum section: electronics / testgear

author: fqahmad66
author_rank: Regular Contributor
timestamp: March 03, 2014, 07:30:09 am
content: Hi,Do the cheap China Power supplies (Hantek/Korad etc.) have actual OVP & OCP implimented? Anybody have any practical experience?RegardsF

author: fqahmad66
author_rank: Regular Contributor
timestamp: March 04, 2014, 04:35:04 am
content: Anyone??

author: commongrounder
author_rank: Frequent Contributor
timestamp: March 04, 2014, 09:29:41 pm
content: I have a Korad KA3005D. Has OVP and OCP. They both work fine once you get them set up.

author: fqahmad66
author_rank: Regular Contributor
timestamp: March 05, 2014, 08:56:09 am
content: Thanks commonground,How do you check it.?RegardsF

author: commongrounder
author_rank: Frequent Contributor
timestamp: March 05, 2014, 03:25:37 pm
content: With the max output (OVP) voltage set, you enable the output. If the voltage rises above the set point, either externally or by raising the voltage while the output is still enabled, the output will turn off. With max (OCP) current set, the output will automatically turn off if the current draw rises above the set point. I haven't timed the shut-off delay, but both are very fast, so one would hope your circuit under test would be protected. I have to say, I don't use these functions too often. I tend to keep the current limit low to start with until I understand how the circuit is going to behave. Hate to see the magic smoke.

author: rollatorwieltje
author_rank: Unknown
timestamp: March 05, 2014, 04:00:25 pm
content: Be careful with the implementation of especially OVP. On some power supplies this means "disconnect the output on overvoltage", on others (HP/Agilent at least) it means "short out the terminals on overvoltage".The latter one can be quite destructive when the overvoltage condition is caused by you connecting something like a battery to the output terminals

author: MarkL
author_rank: Unknown
timestamp: March 05, 2014, 08:18:13 pm
content: Another implementation detail is that the better power supplies will have the OVP/OCP in an *independent* circuit. If the main processor goes out to lunch and decides it's time to apply max voltage, there's a backup to shut everything off quickly.On cheap power supplies, I would be suspicious that it's only a software implementation. Not to say this can't handle many of the failure scenarios, but it's like putting the fox in charge of the chickens.
Any speculation on the Rigol 1000Z and the Agilent 33600? - Page 1
Forum section: electronics / testgear

author: rramirez
author_rank: Contributor
timestamp: March 05, 2014, 03:28:07 pm
content: There seem to be a few variations of the Rigol 1000Z ARB generator out there, but the new Agilent 33600 seems to be a higher-end version of this same basic design as well. A Rigol rep told me they were doing a few entry models for Agilent (my interpretation of this was the same Chinese company was producing multiple variations), so with this in-mind, I had to wonder upon seeing the You-Tube videos on the 33600. I found the Waveform Builder and Benchlink "limited-time" software offers Agilent is offering to be the most appealing aspect of this kit. Thoughts?Russ

author: PedroDaGr8
author_rank: Super Contributor
timestamp: March 05, 2014, 04:45:39 pm
content: Quote from: rramirez on March 05, 2014, 03:28:07 pmThis wouldn't be entirely surprising as Rigol has made some lower end stuff in the past. From what I remember the Rigol DS1204B is very similar to the Agilent DSO1000 series (which were/are made by Rigol).
Tektronix Scope cart thingy - Page 1
Forum section: electronics / testgear

author: Axtman
author_rank: Regular Contributor
timestamp: March 04, 2014, 01:45:38 am
content: What is the purpose of that bar thingy on the Tektronix scope cart? I am referring to the bar on the top shelf that says open on it.

author: guido
author_rank: Regular Contributor
timestamp: March 04, 2014, 01:49:42 am
content: Lock a scope on the cart, so it can't fall off. I have a similar cart (model 3) with a 7704a on it.

author: Mandelbrot
author_rank: Regular Contributor
timestamp: March 04, 2014, 06:15:06 am
content: I have a similar scope cart (Model 3) that came with my Tek 2225. For the life of me I can't figure out what that bar does. I assume it is a locking mechanism specifically for certain models and not compatible with others. It still works fine as a cart though. I'd be interested in hearing more information about it as well.

author: guido
author_rank: Regular Contributor
timestamp: March 04, 2014, 10:32:53 pm
content: yes, a locking system for the heavy scopes. E.g. tek 7000 series. Found a picture on the net from an underside:http://www.ebay.com/itm/Tektronix-7633-Oscilloscope-w-Plug-ins-7A18N-7A12-7B53A-/251266581089The bar grabs into the plastic pieces in the middle of the underside, inbetween the front and rear feet.Then you can tilt the top part of the cart, without theelectronsscope falling out.@free:

author: free_electron
author_rank: Super Contributor
timestamp: March 04, 2014, 11:24:03 pm
content: been at Halted i take it ?

author: linux-works
author_rank: Super Contributor
timestamp: March 05, 2014, 04:10:28 am
content: my guess is 'halted' (hsc electronics), too!(update: nope, it was an ebay photo and not from halted!)
Looking for any manuals for Takeda Riken TR5589L + foto as bonus - Page 1
Forum section: electronics / testgear

author: zigi
author_rank: Contributor
timestamp: March 08, 2014, 08:20:10 am
content: I have searched the internet for a manual for the Takeda Riken TR5589L am can't find one anywhere.Does anyone have a link or know where I could get one?
Multimeter Bluetooht mod - Page 1
Forum section: electronics / testgear

author: Flipp
author_rank: Contributor
timestamp: March 04, 2014, 08:24:03 pm
content: Hi,like i have announced inthistopic, i have played a little with a Bluetooth link module in my CEM DT-9939 multimeter.Step 1:testing pinout of the original wireless module, it was easy to find TX and RX (2400bps,8n1) as well as switched supply pins.protocol is explainedhere(basicaly 4 bit byte id and 4 bit data per byte).Bluetooth module BTM400 aka HC-05 is working and only active while data is sent.Step 2: make it working with a smartphone appThere are 3 similar meters: EXtech EX540, Digitech/Jaycar QM1575 and DT-9939 by CEM which seems to be the OEM.And 3 apps: Digitech DMM:for Jaycar QM1576 and Meterbox /Meterbox HD:for CEM. Its looking pretty similar, isn´t it?All Meters share the same serial Protocol. But the smartphone apps wont even connect bluetooth, obviously they decide by the name of the Bluetooth device. After long testing i worked out a semi-working config by giving the HC-05 the name DT-9939. Digitech DMM app find, connect, detect the right meter and deletes unnecessary buttons, decode and display the data correct. But it does not refresh display, so the first reading stays on display.Has anyone an idea whats wrong in the configuration? It seems to be only one last bit to be discovered.if i want to look into the Bluetooth part of these apps, how can I do? I can find some bitmap and layout data but no actual program or config.Flip
Micsig participated in EFY Expo 2014 in India - Page 1
Forum section: electronics / testgear

author: Micsig
author_rank: Contributor
timestamp: February 28, 2014, 08:10:50 am
content: Shenzhen Micsig Instruments CO., Ltd.(Micsig) participated in Electronics For You Expo, Pragati Maidan New Delhi dated on 20-22 Feb,2014.We launched the first worldwide tablet oscilloscope in the exhibition. The tablet oscilloscope owns 10.1 inches TFT LCD full touch screen, up to 1024*600 high resolution, bandwidth range from 70MHz to 1GHz, 1GSa/s~5GSa/s real-time sampling rate, equipped with multiple serial bus decoding. And Micsig showed touchable handheld multifunctional oscilloscope MS200, MS300 and MS500 series too.

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2014, 08:13:46 am
content: All of these will ended up with the most important question for tablet oscilloscope ... estimated MSRP ?

author: Mark_O
author_rank: Frequent Contributor
timestamp: March 01, 2014, 02:24:34 am
content: Micsig, congrats! That's great news. I assume a (much requested) demo video won't be far behind?

author: Harvs
author_rank: Super Contributor
timestamp: March 01, 2014, 02:50:25 am
content: I noticed the other day all the "touchable" scopes are now available through our local Aus dealer Emona.https://secure1.bluecentral.com/emona/shop/scripts/prodList.asp?idcategory=97&curPage=1&sortField=sortorderedit: try again with the link.

author: Mark_O
author_rank: Frequent Contributor
timestamp: March 01, 2014, 02:51:47 am
content: Looking at that second picture (with the young lady with the backpack sitting in front of two tBooks on the desk), did put to rest one of my burning questions. And raised another.The specs on the unit indicated the depth (thickness) was 60mm, which is almost 2 and a half inches (2.36, to be precise). I remember thinking, "Whoa! That can't be right?". And your previous pictures on the Micsig website lookedmuchthinner than that. (Knowing how big a BNC connector is, the visual impression was a thickness <40mm.)I'm guessing that must have been an early "artist's conception" picture, because the real-world shot from the India Expo wasmuchthicker. Or maybe the angle was such that it gave the "Weight Watchers(tm)" slim view of the side?But the new question was, "What happened to the BNC connectors?" I seenoneon the side now, where they used to be. Maybe that's why the screen on that unit was blank. The contour for the recessed BNC's (so they don't get damaged while carrying it around) also seems to have disappeared?

author: peter.mitchell
author_rank: Super Contributor
timestamp: March 01, 2014, 03:07:37 am
content: Quote from: Harvs on March 01, 2014, 02:50:25 amWow, i wonder if they'll lend one to Dave for a test? They have done so before.