hybridfree/eevblog-posts huggingface dataset:
In-circuit emulation of resistors and capacitors (for automated tuning) - Page 1
Forum section: electronics / testgear

author: WSchroeder
author_rank: Newbie
timestamp: October 22, 2015, 06:55:19 pm
content: I would like to create or purchase controllable resistors and capacitors, with a control range of two orders of magnitude for each. I would like to be able to change the values under computer control. Control of R and C value with a control voltage would be acceptable. I could work out an interface myself.Does anybody know how to do this? Does anybody know of a commercial product that will do this? (GPIB or PXI bus, for example.)This would be in lieu of a resistance/capacitance substitution boxes (with thumb wheels).Thank you.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 22, 2015, 07:15:32 pm
content: R/C boxes always bothered me because they're far too big, and on leads far too long, to be of any use in circuits where you would actually need tuning.Don't throw up your hands and use a trimmer (or other adjustment), strive to understand the underlying circuit and calculate the preferred or ideal value. Right the first time, every time.If it's something that truly needs to have a wide adjustment range, it should probably be done electronically in the first place. Example: RC oscillator circuit with a wide range. Suggestion: replace R with current source; have switchable R or C to select different ranges/multipliers. The switching can be done with more transistors, analog switches, reed relays, etc.Tim

author: unitedatoms
author_rank: Frequent Contributor
timestamp: October 23, 2015, 03:36:05 am
content: Quote from: WSchroeder on October 22, 2015, 06:55:19 pmThere is a GPIB controlled sets of HP relay boxes like HP Agilent 34970A or similar. Meh, for some reason nobody made resistors / capacitors GPIB box yet.

author: Vgkid
author_rank: Super Contributor
timestamp: October 23, 2015, 04:30:59 am
content: IET Labs makes programmable resistance/cap/inductance boxes.
Trouble getting output on a Keithley 236 Source Meter - Page 1
Forum section: electronics / testgear

author: PedroDaGr8
author_rank: Super Contributor
timestamp: October 22, 2015, 02:58:01 pm
content: I borrowed a Keithley 236 from work to run some tests on a multimeter, but I can't seem to get the device to output. I have one triaxial cable, do I need to have all three plus the banana to low? It seemed like ti should be easy but I am kinda lost with this device, it is hands over fists more than any other device I have encountered.
Manson SSP7080 80Watt Lab PSU advice - Page 1
Forum section: electronics / testgear

author: beng
author_rank: Contributor
timestamp: October 21, 2015, 09:42:16 pm
content: G'day All,I recently purchased this model as I needed a constant current and voltage supply for uni work.While I am happy with the price and specs one thing is really annoying.I had assumed that as it used rotary encoders, the accuracy of current or voltage selection would be consistent. Eg one click in either direction would adjust the parameter by XmA or XmV.However what I am finding is that the increase or decrease per click is completely random. Eg say I want to set 4V and so I rotate the Voltage and overshoot to 4.250V rotating back it might go to 3.900V and then fwd again 4.150, reverse 3.600V etcSo it gets very fiddly trying to repeat experimental results.For the price I don't expect perfection. But I would have thought that rotary encoders would be at least consistent.So I have two questions.1)Is this behavior the same for anyone else with this (or another rebadged one. eg Maplin) supply?and 2) If anyone has opened this unit up. Do you think the encoders could be replaced with more accurate components?Thanks, Ben
Recommendation for a 300V DC power supply - Page 1
Forum section: electronics / testgear

author: davorin
author_rank: Unknown
timestamp: October 25, 2015, 01:40:16 pm
content: As one of my many Hobbies is to restore old vacuum tube Radios....which DC power supply would you recommend which can go up to 270 - 300V DC and deliver 0.15A?

author: Cubdriver
author_rank: Unknown
timestamp: October 25, 2015, 01:55:27 pm
content: As far as used supplies go, you might try looking for a Heathkit IP-17 or an HP 711A. Both are only good for 100mA continuous output so they don't quite match your specs, but they do show up occasionally on eBay. The Heath goes to 400V; the HP to 500. I don't know how common they'd be in Europe, nor how much shipping might be from the US, but there are two possibilities at least.-Pat

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 25, 2015, 02:22:50 pm
content: http://www.ebay.ca/itm/DC12V-24-to-DC-200-450V-70W-high-voltage-converter-boost-step-up-power-supply-/181746908549?hash=item2a50f5bd85:g:uykAAOSwv0tVVvMhThis is close. I bought the lower voltage one and it delivers the juice, but I haven't looked at the ripple/noise of the output.

author: Gyro
author_rank: Super Contributor
timestamp: October 25, 2015, 04:05:22 pm
content: I was going to say you could buid your own cheaper, but having seen the cost of the converter in the previous post...Anyway, here's the link:http://sound.westhost.com/project151.htmEDIT: The linear one might be quieter though.

author: nctnico
author_rank: Super Contributor
timestamp: October 25, 2015, 04:19:14 pm
content: I don't like the switching converter. In a lab supply you'll want current limiting and no smoke when it is overloaded.
Rigol DP832 crash - Page 1
Forum section: electronics / testgear

author: st_ashcroft
author_rank: Newbie
timestamp: October 21, 2015, 07:51:28 pm
content: Hi,I've had a DP832 for a a couple of months.It came with the latest firmware (1.14) and I checked that it has the modified board with the larger heatsink.Now it has started to crash within about 30 seconds of boot up. Loads of white lines on the screen.I'm in the UK so it isn't stupidly hot this time of year.Has anybody else had this issue?I bought it from an approved dealer so I'll try to get it swapped out before I take it apart.I'll try and upload a photo.Cheers,Scott

author: st_ashcroft
author_rank: Newbie
timestamp: October 21, 2015, 07:55:44 pm
content: Crash!
How to use Zeroplus LAP-C Logic Analyzer as signature analyzer - Page 1
Forum section: electronics / testgear

author: pelule
author_rank: Frequent Contributor
timestamp: October 21, 2015, 06:48:53 pm
content: HiI need a signature analyzer to test/repair the CPU board of my HP 8116A.http://www.radio-electronics.com/info/t_and_m/signature-analyzer-analyser/basics-tutorial.phpAs it is in principle a level triggered start-stop 16-bit shift register I think it may possible to use the Zeroplus LAP-C Logic Analyzer for that function.Does has anyone experiance with that?BRPeLuLe

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: October 21, 2015, 07:50:11 pm
content: the trigger capabilities on the LAP-C are quite unimpressive, so you may want to trick a little bit with the bus trigger feature. i simply take _all_ channels and _all_ busses into another bus and call it trigger-bus. then, i set BUS TRIGGER SETUP to an event on trigger-bus, after which i assume the interesting data will follow. i also set data acquisition to no compression, and sampling rate to the lowest possible rate (take 10 x highest frequency on probed signals as a starting point). then, let the LA do a one-shot. then, look for the signature in the captured data stream with FIND DATA VALUE. there, "ACTIVATE THE FUNCTION OF CHAIN-DATA FIND", type in the name of the bus you want to analyze (not the trigger-bus) and give the signature you want to find.(any better idea than this very much appreciated!)
Bad Flir E4 batch - Page 1
Forum section: electronics / testgear

author: ne555
author_rank: Newbie
timestamp: October 20, 2015, 11:43:38 am
content: I have tried three Flir E4 one by one from a famous online store,They all work normally when first turning on, but after charging and restart, they all shows problemThe serial number are 63957xxxPlease help to check if your E4 also have this kind of problem!The following step should reproduce the problem.1)at room temperature 25degree,2)turn on the camera and charging the camera for 15 mins with the bundled charger(charging warmup the camera faster than normal usage, for normal usage it may need 30min to reach the temperature for the problem to appear)3)Turn off the camera,4)Turn on the camera again and the problem appear.The condition to reproduce the problem is (1)the camera warmup and (2)after restart.

author: tomas123
author_rank: Frequent Contributor
timestamp: October 20, 2015, 02:25:36 pm
content: it looks like an bad Flat Field Correction (FFC) after step (4)http://www.flir.com/cvs/cores/knowledgebase/index.cfm?CFTREEITEMKEY=591&view=63110soft reset the camera by long press the on button and restartmy E4 lacks sometimes after the cold start (shows no thermal image, only a real image) and need such a hard shutdown

author: ne555
author_rank: Newbie
timestamp: October 20, 2015, 06:57:33 pm
content: hard reset(remove the battery) and soft reset is also tried. reset on the menu also all do not helpthe problem is the same,two camera has pattern on the screen which will never disappear if it showsbut one of the camera shows line across the screen, the line will disappear after the calibration halt for few second and appear again immediately.this is the one with the line problemQuote from: tomas123 on October 20, 2015, 02:25:36 pm

author: tomas123
author_rank: Frequent Contributor
timestamp: October 21, 2015, 08:09:34 am
content: Quote from: ne555 on October 20, 2015, 11:43:38 amI think, you tested the thre cameras out of the box (without resolution hack).Quote from: ne555 on October 20, 2015, 06:57:33 pmAsk your flir support:http://www.flir.com/countrylist.cfm
Fluke 3330B Calibrator buzzing noise - Page 1
Forum section: electronics / testgear

author: Jim Narem
author_rank: Contributor
timestamp: October 19, 2015, 06:58:22 pm
content: I got a Fluke 3330B calibrator on ebay in unknown condition. Aftercleaning it up, it seems to work but it makes a buzzing noise whenin operate mode. The frequency varies with output voltage whichprobably means that the buzzing is related to the VCO that regulatesthe HV transformer power output. It buzzes slower under low loadsuntil it hits a certain point and the buzzing is a constant frequency.I've checked the power supplies for ripple and they look OK. I waswondering if anyone else had used one of these and if the buzzingwas normal. I have another HV power supply (an HP 6521A) whichhas a big notice on the back that says "ticking sound normal" and itmakes a fairly disturbing noise from the pulse transformer as itregulates the HV.......jim (narem at narem dot com)

author: Testtech
author_rank: Regular Contributor
timestamp: October 19, 2015, 08:13:04 pm
content: Yes, these do buzz a bit.. When ever I have repaired any of the Fluke calibrators, the first thing I do is really carefully check all the aluminum electrolytic caps. Most of the small ones will need to be replaced. Also check for overheated carbon comp resistors, a common problem with these. Relays can also be a headache.

author: dacman
author_rank: Frequent Contributor
timestamp: October 20, 2015, 12:18:53 am
content: I maintain a 3330B, and it doesn't buzz at all. Pull the cards and clean the contacts (with DeoxIT). As stated, the little electrolytic capacitors do go bad. If you have a Variac (with a current meter), measure the current draw and make sure someone didn't put in a high value fuse.

author: pelule
author_rank: Frequent Contributor
timestamp: October 20, 2015, 07:44:45 pm
content: My 3330B started one time in the past also buzzering at the highes voltages.It was cause by the pre-regulator board. Thus I would check the e-cap at this board first.Now mine is quite again.
Sumnoon ATE - Page 1
Forum section: electronics / testgear

author: Philipus II
author_rank: Newbie
timestamp: October 20, 2015, 11:47:15 am
content: Hi,I've tried the forums search, but I didn't come up with anything except some duiscussions where JonnyGuru.com was referenced. I'm a member there, off course. For my work here with an IT distributor I'd like to aquire programmable loads for psu testing. Budget is tight, so the good stuff is out of range. I checked the market for an affordable load setup and came up with Sunmoon ATE. I got quotes from both Sunmoon companies.option 1)Sunmoon 8800 ATE 4.03total power: 1620 wattsburn in total power: 800 watts2x300W for minor rails3x300W for +12Vprice: 2500 USDoption 2)Sunmoon 5500 ATE 10 load, single unit1.200W rated6x+12V (5x350, 1x 400W)used by quite a lot of people since Corsair provided several units to European reviewers for freeprice: 2650 USDRunour says the software for the 8800 is way better. Anyone had a 8800? What would you recommend me to do? The Sunmoon 5500 would be powerful enough to fully load all the psu I'd like to check. With the 8800 I could fully load around 90% of the psu and partially load the rest. In the end having any programmable load is way superior to not having any loads except PCs.
HP 3456A "ratio mode" what purpose does it serve? - Page 1
Forum section: electronics / testgear

author: SharpEars
author_rank: Unknown
timestamp: October 19, 2015, 04:56:17 pm
content: I am trying to understand the usefulness of the 3456A's ratio mode for measuring. When is it useful? Assuming I am dealing with two voltage sources that are relatively stable and correlated (i.e., move in unison), is it not exactly the same as taking two voltage measurements and dividing them to find the ratio?Or, is there more accuracy to be gleaned using ratio mode? It is not clear to me how the accuracy of the ratio mode relates to the accuracy of taking two readings and subsequently calculating their ratio using a pocket calculator (assuming of course no voltage drift between the readings as a given).For example, say I am building a 10:1 voltage divider (10 V to 1 V). Assuming I have an extremely stable 10 V source, would I be better served using ratio mode than taking two readings at the 10 V DC range (10.00000 V and whatever my 1 V attempt produces at each iteration) and manually dividing them?

author: MarkL
author_rank: Unknown
timestamp: October 20, 2015, 12:18:34 am
content: I can't think of a reason why it would be any more or less accurate. The specs say:QuoteRatio mode makes three separate measurements and then computes the ratio with the processor. The exact process is described in the service manual in section 8-171. (And not two measurements, as you might expect, because everything is referenced to the VOLTS LOW terminal.)Ratio is just a convenience function, as far as I can tell. But because the three measurements are done close to eachother, there might be an advantage that there's less of an influence from any longer term external or internal drift, but you say that's not an issue with your setup.

author: dacman
author_rank: Frequent Contributor
timestamp: October 20, 2015, 12:28:34 am
content: As an example, if you were calibrating a power sensor (or thermistor mount), and you had a similar gold standard power sensor with a known correction factor, you could set the 3456A in ratio mode (using a third power sensor for the reference) to indicate the value of the correction factor of the standard power sensor, then replace the standard power sensor with the power sensor under test, and read its correction factor directly from the 3456A.

author: dacman
author_rank: Frequent Contributor
timestamp: October 20, 2015, 12:41:36 am
content: Quote from: SharpEars on October 19, 2015, 04:56:17 pmDepends on the spec or if the ratio mode check will do. You can normally use the 24 hour spec for an in-range ratio calculation (measuring 10 V then measuring 1 V, both on the 10 V range, then calculating the ratio).

author: coppice
author_rank: Super Contributor
timestamp: October 20, 2015, 01:07:01 am
content: Ratiometric measurements are very common, especially in sensor work. Nobody needs to care about the reference quality in such measurements, and so in general nobody does. If you want meaningfully accurate measurements from such a circuit you need to follow its imprecise reference, and not some high quality one in your instrument.
Useful Milliohm Meter - Page 1
Forum section: electronics / testgear

author: German_EE
author_rank: Super Contributor
timestamp: October 18, 2015, 03:43:51 pm
content: Scullcom Electronics has a very useful milliohm meter project on his YouTube channel, now we have a use for all of those 5-digit meters on Ebay:

author: SundayProgrammer
author_rank: Contributor
timestamp: October 18, 2015, 05:07:11 pm
content: Now after someone else started the thread I'm wondering... why tantalums (and why not std elcos?)Axel.ps. nice project!

author: German_EE
author_rank: Super Contributor
timestamp: October 18, 2015, 06:42:01 pm
content: If he's like me he will have a bag of 250 that were purchased off Ebay.

author: TerminalJack505
author_rank: Super Contributor
timestamp: October 18, 2015, 07:18:03 pm
content: This is one of my favorite electronics-related YouTube channels. Right up there with Alan's.He deals with practical, useful circuits and (to me, at least) seems to go into just enough detail. A lot of other channels skimp on details or get too bogged down in them.

author: kripton2035
author_rank: Super Contributor
timestamp: October 18, 2015, 08:09:56 pm
content: very nice and detailed explainations.

author: PointyOintment
author_rank: Frequent Contributor
timestamp: October 19, 2015, 01:32:41 am
content: Here is another milliohmmeter optimized for finding short circuits:https://hackaday.io/project/3635-shorty-short-circuit-finder
Cheapest 4 channel scope with video output jack? - Page 1
Forum section: electronics / testgear

author: nbritton
author_rank: Frequent Contributor
timestamp: October 18, 2015, 09:52:32 pm
content: What are the cheapest (bang for buck / less than $2500) 4 channel scopes that have video output jacks?, i.g. VGA, HDMI, DVII know the cheapest Rigol that meets these specs is the DS4000 series. What else is there?

author: rs20
author_rank: Super Contributor
timestamp: October 18, 2015, 09:54:41 pm
content: I got a second hand TDS 754C to fill a similar need; but that's not modern/"bang for buck" by any stretch.

author: frenky
author_rank: Unknown
timestamp: October 18, 2015, 10:15:05 pm
content: Perhaps this would work:- Rigol DS1054Z- Raspberry Pi-https://hackaday.io/project/5807-driverless-rigol-ds1054z-screen-capture-over-lan

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 18, 2015, 10:29:23 pm
content: Used Agilent DSO5014A/6014A (VGA 1024x768 out) - I think the 5000 has VGA - 6000 definitely does ( and can be hacked for MSO,decodes etc.)
Adding GPIB to Datron 1071 - Page 1
Forum section: electronics / testgear

author: gilbenl
author_rank: Regular Contributor
timestamp: October 18, 2015, 08:38:35 pm
content: Over the coming months, I'll finally be getting to building the GPIB controlled rack I've been planning (my 82357B is finding its way stateside from China, presumably by some guy in a canoe at this rate). I would like to include my Datron 1071 in the rack, however, it presently lacks the GPIB board. I've got an extra Datron GPIB board from a 1062 that I'm thinking could be used.My 1071 is missing M18 EEPROM, but the FW is available on KOBB. I'm assuming I'll need to flash M3 on the 1062 GPIB board with the 1071 FW, but don't know whether it'll be plug and play or more involved beyond that-eg.: M18 has a hand in the mix. Anyone know?***My apologies-I put this thread under the wrong topic. Please move to repair!
DS2072A - full 300Mhz all options upgrade plus bricking & unbricking - Page 1
Forum section: electronics / testgear

author: Mosaic
author_rank: Regular Contributor
timestamp: October 18, 2015, 05:36:13 am
content: Yes..the title says it all.Anyhow, I thought I'd make a new post cuz there's a 'gotcha' with the new DS2072A , HW 2.0 , FW 3.0 SP1 which I just got 2 days ago, brand new.Ok....the full options upgrade doesn't brick the unit. So don't worry...the recent FW upgrade did. This one....not that it's bad or anything.http://beyondmeasure.rigoltech.com/acton/fs/blocks/showLandingPage/a/1579/p/p-001a/t/page/fm/0I'm telling this backwards to answer the most pressing matter first....bricking.The DS2072A responded to my inserting a 4MB flash with the latest FW by a pop up - 'New FW detected' ; Install?You get a soft button OK/cancel option. Well, I chose 'OK' (smart scope, I thought) .....a progress bar pops up and after about 75% (3mins) it gets stuck. 1 hour later it's still stuck. By this time I have discovered this instruction document on the same page of the FW, duh...http://beyondmeasure.rigoltech.com/acton/fs/blocks/showLandingPage/a/1579/p/p-001a/t/page/fm/0Ok, I bite the bullet and reboot...naturally bricked at the RIGOL splash screen.Unbricking:Follow the instructions in the FW PDF....they work. Unbricked in 3 mins.Also..all prior 'upgrades' still in place.....on to that..To summarize the simplest upgrade path:1) Post #3668 here:https://www.eevblog.com/forum/testgear/sniffing-the-rigol's-internal-i2c-bus/3660/execute the instructions to get the 'scope binary dump, USB conn. works fine. U should run the 'Rigol USB.exe' utility with admin privileges to make the binary file:ds2072a.bin2) DL the rigup 0.4 file from this post.3) Copy the binary file (ds2072a.bin) into the folder u extract the rigup.exe and open a DOS window there to execute this cmd: rigup ds2072a ds2072a.bin4) Now u have your option keys, note the black pic attached.5) Execute the Rigol Ultra Sigma utility....(should be on your Scope CD or get it from Rigol's site)http://www.rigol.com/download/China/DG/PC_SW/Ultra%20Sigma(PC)Installer.rar6) Note the pic with the Ultra Sigma instructions to update the 'scope.When entering your key...leave out the NS8H: and all the dashes in between the 4 sets of 7 alpha numerics. You get one continuous 28 char. entry.Execute Send and you're done....scope does a quick progress bar and auto reset.Thanks to all those who made this possible, you rock!PS:This 2072A came with FULL 300Mhz probes, RP3300A , 10X units. Quite the value from Rigol!
What exactly is oscilloscope waveform update? - Page 1
Forum section: electronics / testgear

author: Boscoe
author_rank: Frequent Contributor
timestamp: October 21, 2015, 02:46:37 pm
content: When a manufacturer quotes 50,00 waveform updates per second what is actually happening when the display is only being refreshed less than 60Hz?Also if a scope doesn't have a graded intensity display how would you effectively display 1Gsa/a (for example) of information?Thanks

author: nctnico
author_rank: Super Contributor
timestamp: October 21, 2015, 03:34:42 pm
content: Combine multiple acquired waveforms into one trace.

author: zapta
author_rank: Super Contributor
timestamp: October 21, 2015, 04:10:59 pm
content: Quote from: nctnico on October 21, 2015, 03:34:42 pmSo, the display update rate is still low (~60 fps)? Do they specify this rate?

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: October 21, 2015, 04:35:06 pm
content: The 'waveform update rate' is actually a bit of a misnomer these days, as what it really means is the trigger rate (i.e. how many triggers a scope can process per second). Back in the old days with analog scopes the trigger rate was identical to the rate the waveform was refreshed on the screen. However, DSOs capture the waveform into the sample memory, and depending on the settings the waveform on the display of a DSO might only show a part of the captured waveform.

author: nctnico
author_rank: Super Contributor
timestamp: October 21, 2015, 04:52:33 pm
content: Quote from: zapta on October 21, 2015, 04:10:59 pmIf a display would be updated 50000 times per second you'd miss 99.9% of the signals. Your eyes can keep up with about 5 updates per second so what you want is that each acquisition stays on screen for at least 200ms. In old analog scopes the phosphor takes care of keeping the trace longer on the display. A DSO needs to combine many acquisitions into one trace on the screen where the oldest acquisition fades away.
Request for DSO8060 RS232 serial lead pin out - Page 1
Forum section: electronics / testgear

author: pete.cross@ihug.co.nz
author_rank: Newbie
timestamp: October 17, 2015, 10:55:34 pm
content: I request the correct pin out for the RS232 serial lead that connects the Hantek DSO8060 handheld scope to a PC serial port, please.I received a DSO8060 Hantek handheld scope, with a DB9 female to RJ45 lead with the following connections.DB9 female pin RJ45 pin------------------- ----------------1 No connection2 73 44 85 No connection6 No connection7 58 No connection9 ?No connectionThis cannot be correct, because pin 5 on the DB9 is used for signal ground. If this is not connected, then it will not work. Can you please reply with the correct pin out for this lead?Thank you for your efforts in this.I will send you a chocolate fish if your post gets it working !!(Offer valid till 25 Oct 2015).... O0
Tonghui TH2822A Vs Der EE DE-5000 LCR meters. Which one to choose? - Page 1
Forum section: electronics / testgear

author: dav
author_rank: Regular Contributor
timestamp: October 17, 2015, 11:32:46 am
content: Hi to all,I'm looking for a decent entry level LCR meter with ESR.Test frequency is up to 10kHz for the Tonghui and 100kHz for the DE-5000.Price is about US$190 shipped (no custom fees) for the first one and about US$120 shipped (+ custom fees) for the second.I read the Tonghui can be hacked, adding 100kHz test signal.Which one do you suggest?
Correct Firmware for Rigol DS1054z? - Page 1
Forum section: electronics / testgear

author: mikefromsac
author_rank: Contributor
timestamp: September 25, 2015, 02:39:27 pm
content: I have a new DS1054z oscilloscope that I hacked to a DS1104z. When I request a firmware update from Rigol, is there a difference? If so, do I request the DS1054z version?

author: Lightages
author_rank: Unknown
timestamp: September 25, 2015, 05:47:46 pm
content: There is no difference. Just ask for the latest DS1000Z firmware

author: MarkF
author_rank: Super Contributor
timestamp: September 25, 2015, 06:08:48 pm
content: Just download it here:Version 00.04.03.01.05

author: mikefromsac
author_rank: Contributor
timestamp: September 25, 2015, 08:14:39 pm
content: Thanks again guys!

author: Smokey
author_rank: Super Contributor
timestamp: October 17, 2015, 04:00:24 am
content: might be nice to have a firmware changelog type page. It's not easy digging through the (currently) 117 pages of the main thread.

author: Stupid Beard
author_rank: Regular Contributor
timestamp: October 17, 2015, 04:19:45 am
content: Quote from: Smokey on October 17, 2015, 04:00:24 amThe first page of one of the long threads was being kept up to date with recent release notes. I don't recall which one it was now, but it may have been the bug thread.

author: MarkF
author_rank: Super Contributor
timestamp: October 17, 2015, 04:55:04 am
content: The latestRelease Notesfor the DS1000Z series.
HIOKI 4212 multimeter pictures - Page 1
Forum section: electronics / testgear

author: mirkot
author_rank: Newbie
timestamp: October 20, 2015, 02:08:05 am
content: I got this today in mail. Not much a tear-down, only a few pictures to give you impression what you get for about $90 USD.https://www.hioki.com/products/dmm_insulation_clamp/dmm/1422

author: deadlylover
author_rank: Frequent Contributor
timestamp: October 20, 2015, 02:23:20 am
content: Wow thanks for sharing, it looks pretty nice!Tough choice between the Hioki DT4212 and the Brymen 257S, the Hioki is $40 cheaper on eBay.How's the continuity mode mate?

author: mirkot
author_rank: Newbie
timestamp: October 20, 2015, 02:34:06 am
content: Continuity is non-latching but it is quite fast and not too scratchy. If I touch them quickly it misses only occasionally. Probes are nicely gold-plated so that probably contributes. I would say that the whole thing is pretty well made.

author: retiredcaps
author_rank: Super Contributor
timestamp: October 20, 2015, 02:59:53 am
content: Thanks for the pictures.As I suspected and now proven, this Hioki is a Der ee DE-240 rebadged meter.It looks like it has decent input protection with a PTC, spark gap, current limiting resistor, diode bridge and SIBA fuses.http://www.deree.com.tw/de-243.html

author: mirkot
author_rank: Newbie
timestamp: October 20, 2015, 03:14:11 am
content: Good catchIt looks exactly like DE-243 and specifications are identical as far as I can say.If further proof is needed, board is stamped with DE240-BP7

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 20, 2015, 08:09:25 am
content: Wow, looks definitely like a quality meter. Thanks for sharing, always interesting to see the insides of multimeters!

author: Lightages
author_rank: Unknown
timestamp: October 20, 2015, 03:13:11 pm
content: Yes, that looks very nicely built. 4000 count is OK, and the update rate of 3 per second is not bad. Maybe you could send it to joeqsmith for torture!

author: nowlan
author_rank: Frequent Contributor
timestamp: October 20, 2015, 03:15:41 pm
content: I looked into hioki earlier, and saw references to DER, but the model was discontinued?
Missing video teardown - Page 1
Forum section: electronics / testgear

author: microcircuit
author_rank: Newbie
timestamp: October 16, 2015, 07:30:46 pm
content: Hi, not sure if its because Siglent were unhappy about Dave's comments about their metalwork but it would appear that EEVblog #805 isn't listed under Episodes.

author: tautech
author_rank: Super Contributor
timestamp: October 16, 2015, 07:36:29 pm
content: Quote from: microcircuit on October 16, 2015, 07:30:46 pmWelcome to the forumYes this has been noticed and questioned in this thread:https://www.eevblog.com/forum/blog/error-blog-805-siglent-teardown-not-showing-on-front-page/As to why?Time will tell.

author: microcircuit
author_rank: Newbie
timestamp: October 16, 2015, 07:49:30 pm
content: Many thanks for the welcome and the link to the thread tautech.Like Dave not reading instruction manuals perhaps I should have read the note about conducting a search before posting!!!!

author: crispy_tofu
author_rank: Super Contributor
timestamp: October 16, 2015, 08:26:00 pm
content: Quote from: microcircuit on October 16, 2015, 07:49:30 pmWe all make mistakes!And yes, it skipped from #804 to #806. Still wondering why
Trio CS-1560A II Age? - Page 1
Forum section: electronics / testgear

author: littlejon
author_rank: Newbie
timestamp: October 16, 2015, 08:43:20 am
content: I got my first oscilloscope today. A Trio CS-1560A II (in picture). I was wondering how old this scope is. There are no identifying dates on the outside of the case at all. It is in really good condition and has been kept very clean during it's life.Now I need to learn how to use it properly :-)I have found the service manual for this through searching the forum but I was wondering if anyone had on hand any other user manuals. The input's list the capacitance and impedance, but no mention of the max voltage that it can handle either.Any info will be greatfully received.Cheers.

author: DrGeoff
author_rank: Frequent Contributor
timestamp: October 16, 2015, 08:49:46 am
content: I still have one of those sitting under the bench, not used these days. I bought it back in 1982, it was newish on the market then.From memory it was 15MHz dual trace, 10mV/div max sensitivity.

author: mstck
author_rank: Contributor
timestamp: October 16, 2015, 03:38:04 pm
content: HiI cannot say specifically how old your unit is, but I have a CS 1566 which was purchased in 1979. I would not be surprised if your unit is a bit older.Please check the specification page in the service manual and you will see that the maximum input voltage is 600 v p-p or 300V (DC + AC peak).I hope this helpshttp://bee.mif.pg.gda.pl/ciasteczkowypotwor/Kenwood/cs1560a.pdf

author: littlejon
author_rank: Newbie
timestamp: October 16, 2015, 08:34:43 pm
content: Thanks for the info, is there an difference between the CS-1560A and the unit marked with II? I cant find any reference to a version two anyware.Quote from: mstck on October 16, 2015, 03:38:04 pmSorry - Newbie mistake, I had read that a couple of weeks ago when I first found the scope and was considering bidding. I should have looked again before asking.Thanks.Jon
Signal Hound USB-SA44B Review - Page 1
Forum section: electronics / testgear

author: blueskull
author_rank: Unknown
timestamp: October 16, 2015, 04:55:01 pm
content: USPS dropped this item on my doorstep a couple minutes ago, so I am thinking to do a quick review.This item comes with 4 pieces of near field EMI probes for EMI pre-compliance testing.What you guys want me to include in the review?

author: davorin
author_rank: Unknown
timestamp: October 16, 2015, 04:57:08 pm
content: I'm specially interested in the EMC probes stuff...I just have the SA44B alone.....thought about selfmade probes...but read that it would Need a correction amplifier...Did they come with an amplifier?

author: davorin
author_rank: Unknown
timestamp: October 16, 2015, 05:07:41 pm
content: Hmm...so why are many companies selling those probes in combination with amplifiers?Just to make more bucks?Do you have a pointer to the application note?
4-20mAmp supply for testing - Page 1
Forum section: electronics / testgear

author: jwhitmore
author_rank: Regular Contributor
timestamp: October 14, 2015, 10:09:59 pm
content: I'm currently working on a 4-20mAmp sensor system, so to test this I wondered if I could get a piece of kit that would emit a 4-20mAmp signal, maybe in a standard wave form like a sine wave or something, but with very long period. I'm taking a sample every one or two minutes so given that sampling rate some formula, can't remember which, would dictate the frequency of the signal that I'd recognise as what I was expecting.Maybe given that really low frequency the easiest thing to do would be to rig up a circuit to a micro controller that could output a current. Seem to remember an early eev blog video on creating a current sensor. Not exactly calibrated but maybe?I'm embedded SW so have limited experience of test gear, (can just about use a scope ;-) so maybe a basic signal generator can do this. My only issue might be that I'm going to leave the unit on for a soak test of weeks duration.

author: langwadt
author_rank: Super Contributor
timestamp: October 14, 2015, 10:24:15 pm
content: Quote from: jwhitmore on October 14, 2015, 10:09:59 pma 4-20mA input is usually just a resistor to ground so the the input current generates a voltage suited for ADC, for example 150R for 0-3.3V with 0-22mAso a signal generator between the input and ground would most likely work, just remember to take the output impedance of the generatorinto account

author: orion242
author_rank: Unknown
timestamp: October 14, 2015, 10:31:36 pm
content: Something like this this is what alot of hvac techs use.http://www.kele.com/tools-and-test-equipment/signal-generators.aspxA current limited power supply or a lm317 setup in current control would get the job done for alot less.

author: jwhitmore
author_rank: Regular Contributor
timestamp: October 16, 2015, 09:08:08 am
content: Thanks a million for the info, I'm tempted to build something based on the lm317 but I'll have to think about it.
Rigol DS2000 series High-resolution mode bandwidth, how is it determined - Page 1
Forum section: electronics / testgear

author: ab initio
author_rank: Newbie
timestamp: October 15, 2015, 09:34:16 pm
content: Hi all,I can't seem to understand exactly what my ds2072a is doing when operating in "HighRes" acquisition mode. In theory, it is quite simple to understand: the scope samples a signal at a rate *hopefully* much higher than the actual signal's bandwidth (i.e., we have anoversampledsignal) and then uses a low-pass filter and decimation (e.g., boxcar averaging) to produce a downsampled signal with increased resolution. Here, if the number of samples in the average is N, then the expected increase in resolution given in units of bits isIncreased resolution in bits = 1/2 * log2( N )For the ds2072a, the high resolution acquisition should provide effective 12 bit resolution at the expense decreased bandwidth.This concept is completely fine with me; however, I fail to understand how it is actually implemented, because the results I see on the scope imply something else is going on under the hood. Namely, the theory of operation and the actual bandwidth in highres mode seem to be in disagreement.I'm sure you all are about to post this link, so let me beat you to it:Quote from: marmad on October 30, 2012, 12:30:18 pmHere's my issue: Hooking up the probe to the probe 1kHz probe compensation signal and setting the time base for 20ms/s, and acquire to "normal", the scope samples at 50MSa/s and creates a nice intensity graded display indicating a signal predominately at 0V and at 3V.[see Figure1]Now, setting the scope to "high res" acquire mode, the signal is badly aliased. Why?[see Figure2]The signal is 1kHz square wave. The sample rate is 50MSa/s and with 256 point averaging, therefore, the effective bandwidth should beEffective bandwidth = Min( Analog bandwidth, (SampleRate/2) / N )Since the scope's analog BW is well above everything else, all we need to worry about is the BW of the sampling/averaging combination. Here, 50 MHz/2 / 256 = 96 kHzSo what is going on? 96 kHz >> 1 kHz such that I expect the 1kHz square wave and plenty of its harmonics to be correctly captured using High-res acquisition mode! I expect a nice intensity graded display indicating most of the signal is at 0V and at 3V, not the absolute garbage I'm seeing. Why does the bandwidth appear to be really poor and the display horribly aliased?Furthermore, it doesn't seem like the data is simply being decimated first to 700*256 samples, then being boxcar averaged, and then decimated down to 700 display points. At the 50 ms/div time base, the rigol outputs something like Figure3[see Figure3]However, if it was just pre-decimating, averaging, and the plotting the 700 averages, it should look like Figure4[see Figure4]It looks like neither!? How are the bandwidths in that tabled determined, and why are they so low compared to what the should be given 256 sample boxcar averaging and the scope's sample rates?What is going on?Cheers
R&S CRTU-RU/CMU200 I/Q vs. Slot measurement - Page 1
Forum section: electronics / testgear

author: davorin
author_rank: Unknown
timestamp: September 27, 2015, 05:18:52 pm
content: Good evening (o;I mostly use my CRTUs in DOS mode for displayng the FR spectrum of a Signal...But...does someone know how I could anything displayed on the I/Q vs. Slot measurement screen?Would I see the modulation waveform of a signal?

author: fisafisa
author_rank: Regular Contributor
timestamp: October 15, 2015, 08:47:02 pm
content: I got something displayed there but I do not understand what is going on.

author: davorin
author_rank: Unknown
timestamp: October 15, 2015, 08:56:21 pm
content: Well...my device has the Q/I outputs at the back...dunno why they used VGA sockets for it (o;Have to dig out some VGA cables and connect it to my 9354 DSO and look what's coming out (o;
TDS 5xx, 6xx, 7xx Bulk voltage in power supply - Page 1
Forum section: electronics / testgear

author: tbsmith
author_rank: Contributor
timestamp: October 15, 2015, 07:53:41 pm
content: Does anyone happen to know what the bulk voltage on the main cap (C12) should be? Mine measures 370 and I've seen others mention 400V. I'm wondering if that is below spec and why the rest of the circuit isn't working (the shutoff pin, #10, on the 3525A PWM controller is high indicating that something isn't right).Thanks
Audio generator info needed - Page 1
Forum section: electronics / testgear

author: patra710
author_rank: Newbie
timestamp: October 15, 2015, 02:56:48 am
content: Hi, I have been working on some vintage stereos and when I get to the phono board I find that the input to them is 1.5 milli volts. I have been using a B&K function generator but it only go as low as 50 milli volts. So I been looking at audio generators but their specs only show max output. How can I find the proper output of a board if I can't put the proper input into it? Does anyone know how low an audio generator of reasonable cost will go? Thanks for any help I may get

author: kc8apf
author_rank: Regular Contributor
timestamp: October 15, 2015, 04:13:00 am
content: Why not attenuate the function generator's output?

author: patra710
author_rank: Newbie
timestamp: October 15, 2015, 04:31:01 am
content: How would I do that?

author: jitter
author_rank: Frequent Contributor
timestamp: October 15, 2015, 04:43:43 am
content: How about a resistor divider?

author: patra710
author_rank: Newbie
timestamp: October 15, 2015, 04:45:28 am
content: Thanks, I'll try that.

author: Richard Crowley
author_rank: Super Contributor
timestamp: October 15, 2015, 04:49:13 am
content: If you are testing a phonograph preamp, remember also that it is NOT FLAT. It uses the RIAA compensation curve.There are many circuits on the interweb for making "reverse-RIAA" filters which allow you to measure how well the preamp complies with the curve.Here is an example of one (which also includes attenuation down to typical phono cartridge levels)...

author: DimitriP
author_rank: Super Contributor
timestamp: October 15, 2015, 05:24:12 am
content: ...and since we are on the subject of reverse RIIA networks, this thread would be incomplete without mentioning this one from Haggerman with -40 and -60 db outputshttp://www.haglabs.com/collections/accessories/products/iriaa2-inverse-riaa-filter

author: patra710
author_rank: Newbie
timestamp: October 15, 2015, 07:05:02 pm
content: Thanks for all of the info. I want to do more then just replace components. I never heard of a RIAA compensation curve, so I guess I got a lot of reading and experimenting to do.
Remote control of HP 16702A with Keysight connection expert - Page 1
Forum section: electronics / testgear

author: davorin
author_rank: Unknown
timestamp: October 15, 2015, 10:10:34 am
content: The Agilent, or nowadays Keysight IO library utilities has the Option to connect to a device via TCPIP.How can I connect to a HP 16702A? What do I set as protocl in the Keysight Connection expert?
Waveform characterization using an oscilloscope vs a DC source - Page 1
Forum section: electronics / testgear

author: SharpEars
author_rank: Unknown
timestamp: October 13, 2015, 05:29:24 pm
content: Some of the more expensive DC sources (e.g., Keysight 66312A, 66319B/D, 66321B/D) can perform waveform characterizations with 2048-4096 data points and voltage/current measurements and less than a 50 uS sample rate. I am wondering if there are any advantages to using them vs a cheaper DC source and a decent oscilloscope?In other words, these sources seem to combine oscilloscope functionality with a power supply, if I understand how they work properly. However, is there some killer feature that they offer that cannot be accomplished using a cheaper source and a scope?

author: Marco
author_rank: Super Contributor
timestamp: October 13, 2015, 05:54:16 pm
content: They can put a current measurement shunt above a MOSFET pass element so it has no burden voltage, can't do that with your scope.

author: SharpEars
author_rank: Unknown
timestamp: October 13, 2015, 06:08:39 pm
content: Quote from: Marco on October 13, 2015, 05:54:16 pmSo if I wire a low resistance current shunt in series with the device under test, which will be bypassed for purposes of voltage measurement/regulation due to the sense wires that will be connected to the device under test, I will not get the same effect?

author: Marco
author_rank: Super Contributor
timestamp: October 13, 2015, 06:17:32 pm
content: Yeah, if your power supply has a sense wire my argument is wrong in retrospect.

author: SharpEars
author_rank: Unknown
timestamp: October 13, 2015, 07:45:28 pm
content: Quote from: Marco on October 13, 2015, 06:17:32 pmSo it seems like these expensive mobile test sources have no advantages at all, except for perhaps very fast transient response to changing loads?

author: Someone
author_rank: Super Contributor
timestamp: October 13, 2015, 10:29:20 pm
content: Quote from: SharpEars on October 13, 2015, 05:29:24 pmYou could end up paying more for a current probe than the power supply to make the same measurement, the other value in these power supplies are their fast transient responses.
Good Spectrum Analyzer - Page 1
Forum section: electronics / testgear

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 30, 2015, 04:33:34 pm
content: I'm looking for a good Spectrum Analyzer that won't break the bank, about $4,000 US is my limit. I'd like to be able to:1. Test 2.4 and 5.8 GHz antenna - PCB and SMA-connected - ideally with VSWR info too2. Perform Pre-compliance EMC testingI looked at an Agilent 8595E with tracking generator option but it looks like the TG only goes up to 2.9 GHzAny suggestions or ideas would be welcomed.Thanks

author: TheSteve
author_rank: Unknown
timestamp: September 30, 2015, 05:23:42 pm
content: You could look at the N1996A - there are 3 and 6 GHz models. They have an internal return loss bridge to display SWR. Having an internal bridge isn't very common - especially one that goes to 6 GHz. By default the option features such as the Stimulus Response suite are not enabled but with a little "effort" all of the extras can be brought to life. I have attached a screen shot of the dual band antenna from my Netgear R7000. I haven't looked into using it for EMC pre-compliance. It does have USB for screen shots but doesn't seem very well supported for automated measurements.

author: hendorog
author_rank: Super Contributor
timestamp: September 30, 2015, 06:40:00 pm
content: If you don't mind USB instruments, check out Signalhound -www.signalhound.comThere are two bundles which cover your frequency range:BB60C + TG124A => $4215 (note including directional coupler)SA124B + TG124A => $3098 (note excludes directional coupler)The BB60C is a realtime spectrum analyser vs the SA124B which is narrowband. On the other hand the SA124 goes up to 12GHz whereas the BB60 stops at 6GHz.Here is a discussion on their forums about EMC testing btwhttps://signalhound.com/support/forums/topic/bb60-for-emc/

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: October 01, 2015, 11:42:36 am
content: Thanks for the suggestions guys.TheSteve - he N1996A looks like a really nice contender for my needs, there are a couple on eBay but nothing that looks like a bargain but, if I saw one at the right price. Is there a link to how to expend "the effort" to unlock the inner secrets of the N1996A?

author: LogicalDave
author_rank: Regular Contributor
timestamp: October 14, 2015, 02:57:47 pm
content: There is a ton of used cellular gear on eBay and some of it provides general RF analysis capability at incredible value. For example, the HP E7495 (A or B) is a portable-ish, modern-ish (big color LCD display) test set designed for maintaining cell towers. It is routinely available on eBay for under $1K and includes a spectrum analyzer good to 2.7GHz; it can also take return loss measurements which are a necessity when developing antenna systems. I've also been happy with Anritsu gear on eBay including their MS8609 digital mobile radio tester that includes a specAn good to 13GHz and can be had with an internal Rubidium standard. These are often on eBay for $2-4K.I've put a description of the RF gear I use on my blog including links to datasheets and manuals:http://www.dalbert.net/?p=273Good luck!
Rigol Interfacing - Page 1
Forum section: electronics / testgear

author: Wilksey
author_rank: Super Contributor
timestamp: October 13, 2015, 08:19:38 pm
content: Apologies if this has already been mentioned, I do not own a Rigol scope, but thought it might be of use to some of those who do and can program.http://www.codeproject.com/Articles/869421/Interfacing-Rigol-Oscilloscopes-with-C

author: alank2
author_rank: Super Contributor
timestamp: October 13, 2015, 10:07:13 pm
content: Thanks for the post; looks like something fun to try out.