hybridfree/eevblog-posts huggingface dataset:
Protocol type? - Page 1
Forum section: electronics / testgear

author: eti
author_rank: Super Contributor
timestamp: October 20, 2020, 03:13:10 am
content: Forgive my ignorance, I am probing the output of the COB IC of my "Kaiweets" HT118A DMM, hoping to find RS232 being pumped out, and I came across this waveform (pin # impossible to know, since it's COB)... does anyone recognise this?{Update}: I've attached a zipped pulseview session too.Thanks!

author: eti
author_rank: Super Contributor
timestamp: October 20, 2020, 08:37:59 pm
content: Gosh, no one?

author: tautech
author_rank: Super Contributor
timestamp: October 20, 2020, 08:42:02 pm
content: Quote from: eti on October 20, 2020, 08:37:59 pmLooked yesterday and all I could see was several clock bursts.

author: eti
author_rank: Super Contributor
timestamp: October 20, 2020, 09:43:08 pm
content: Quote from: tautech on October 20, 2020, 08:42:02 pmThanks for looking- I have captured more in "PulseView" and applied the "UART" filter - how does one know how accurate said filter is, though? Is there some form of file format I could share here, to make the full capture more accessible to people who could ID the pulses?Cheers!

author: eti
author_rank: Super Contributor
timestamp: October 23, 2020, 07:01:41 pm
content: Is this any more meaningful?:

author: abyrvalg
author_rank: Frequent Contributor
timestamp: October 23, 2020, 11:09:00 pm
content: This doesn't look like UART at all. Should be a clock line of some synchronous bus transferring 8-bit values (8 shorter pulses separated by a longer one). Are there any other signals belonging to the same bus? (i.e. other pins of the same connectors or PCB pads grouped together with this one). Look for a data signal clocked by this line (some less regular signal with a frequency <=1/2 of this clock, with all transitions during the same clock levels).

author: eti
author_rank: Super Contributor
timestamp: October 24, 2020, 12:44:04 am
content: Quote from: abyrvalg on October 23, 2020, 11:09:00 pmI'll look, thanks. But if it's not UART, why does the UART filter seem to (sort of) decode it?

author: srb1954
author_rank: Super Contributor
timestamp: October 24, 2020, 01:03:03 am
content: Quote from: abyrvalg on October 23, 2020, 11:09:00 pmIt might be just be the clock line of an SPI bus whilst transmitting a multi-byte message.
What gcc toolchain to use for cross-compiling on Siglent scopes - Page 1
Forum section: electronics / testgear

author: puterboy
author_rank: Regular Contributor
timestamp: October 08, 2020, 04:57:47 pm
content: I have a Siglent SDS1104X-E and would like to cross-compile Linux programs to run on it.Anybody know where I can get a freely available cross-compiler toolchain?In the past I have used toolchains from Code Sourcery and from GNU.uname -a shows the Linux version and processor as:Linux (none) 3.19.0-xilinx-svn8988 #187 SMP PREEMPT Wed Feb 28 18:55:09 CST 2018 armv7l GNU/LinuxThanks

author: RoGeorge
author_rank: Super Contributor
timestamp: October 08, 2020, 05:07:36 pm
content: GCC should be able to crosscompile and generate binary code for ARMv7.

author: switchabl
author_rank: Frequent Contributor
timestamp: October 08, 2020, 05:36:36 pm
content: This is ZYNQ-7000 based, right? In that case the arm-xilinx-linux-gnueabi toolchain included in the Xilinx SDK (https://www.xilinx.com/products/design-tools/embedded-software/sdk.html) is probably the way to go.

author: uski
author_rank: Frequent Contributor
timestamp: October 22, 2020, 05:26:24 am
content: You might run into issues with the libc and mismatches. Might want to do static linking or ship all the libraries with the program itself and possibly use LD_LIBRARY_PATH.
Any experiences with the new (?) Voltcraft benchtop DMM VC-7200BT or clones? - Page 1
Forum section: electronics / testgear

author: PushUp
author_rank: Regular Contributor
timestamp: October 21, 2020, 09:34:49 pm
content: Any experiences with this benchtop DMM from Voltcraft?I have never heard of it before - of course nothing special, but interesting design like a mixture of a newer Rigol and Siglent... Normally Voltcraft is a clone from another brand, like "RS Pro" or "Teledyne LeCroy" from Siglent benchtop DMMs, isn't it?!You probably need to change the language from the links:55000 Count - VC-7055BT = 215€https://www.conrad.de/de/p/voltcraft-vc-7055bt-tisch-multimeter-digital-datenlogger-cat-i-1000-v-cat-ii-600-v-anzeige-counts-55000-2203066.html60000 Count - VC-7060BT = 400€https://www.conrad.de/de/p/voltcraft-vc-7060bt-tisch-multimeter-digital-datenlogger-cat-i-1000-v-cat-ii-600-v-anzeige-counts-60000-2203067.html200000 Count - VC-7200BT = 537€https://www.conrad.de/de/p/voltcraft-vc-7200bt-tisch-multimeter-digital-datenlogger-cat-i-1000-v-cat-ii-600-v-anzeige-counts-200000-2203068.htmlCheers!

author: TurboTom
author_rank: Super Contributor
timestamp: October 21, 2020, 10:52:06 pm
content: Get the same instrument (albeit not black) at a much lower price tag here:https://eleshop.eu/owon-xdm3051.html

author: jogri
author_rank: Frequent Contributor
timestamp: October 21, 2020, 11:45:14 pm
content: Except that Voltcraft is almost always overpriced chinese crap from brands like Owon (Scopes) or Manson (for PSUs). Their handhelds are usually Uni-T ripoffs, but i would stay away from this brand (and Conrad in general) as they are overpriced and don't offer quality in most cases. The only reason i still use Conrad sometimes is because they have rather nice assortment of components in their shops and it's sometimes cheaper to buy at their inflated prices than to ship a handfull of components from Mouser or Farnell.A reverse image search will probably yield the original manufacturer for most of their stuff...
121GW Korea Availability? - Page 1
Forum section: electronics / testgear

author: SeoulBigChris
author_rank: Regular Contributor
timestamp: October 21, 2020, 10:55:31 am
content: I guess the answer will be “no”, but thought I’d ask just to be sure. Since I live in South Korea, any way we could save shipping costs by getting one locally? I could even drive by the manufacturer and pick it up, if they had any extra or blemished units on hand. I’d just pay you the normal way on your store but no shipping fee.-Chris, TheStumbler
HP/Agilent 6642 Recapping - Page 1
Forum section: electronics / testgear

author: lucatz
author_rank: Contributor
timestamp: October 21, 2020, 12:55:53 am
content: Hi All,Purchased a HP 6642a looks from date code on some chips that it was built around 1994, so 26 years old...Works fine from preliminary tests but I would prefer swapping out RIFA Film caps and Electrolytic. RIFA where not an issue. But the Electrolytic are another story... they are 3 pin, so if I change them for 2 pin they no longer fit as they will not line up correctly.What have some of you done to change out 3pin to 2 pin as they are really hard to source. Just get some with long pins and make it work? Insulate whatever sticks out? Tried Digikey and MouserTksLuca

author: TERRA Operative
author_rank: Super Contributor
timestamp: October 21, 2020, 08:52:00 am
content: Check to make sure those electrolytics are actually bad. I'd pull one or two and test them, if they test good, the rest are likely fine too.I have a similar unit (6644A) and it tests ok, if you download the service manual, it details how to test the output ripple and PARD etc to see if the unit is within specifications.As for the Rifa caps, rip those things out pronto!
Electronic load for testing low voltage high current PoL supplies - Page 1
Forum section: electronics / testgear

author: asmi
author_rank: Super Contributor
timestamp: October 20, 2020, 03:28:12 pm
content: Hey TE gurus over here! I am designing a PoL power supply for midrange FPGA device, which requires up to 30 Amps @ 1V, so I wonder if cheap-ass DC load (like Rigol DL3021(A)) is going to do the job, or there are any issues working with such low voltages? FPGA that will be powered by this PS is rather picky about the quality of the power on this rail (ripple voltage, regulation precision, noise level all need to be in check over wide range of power consumed), so I will need to perform quite precise measurements, and it won't be possible if EL itself will add enough noise to ruin precision. Just to give you an idea of the kind of numbers we're talking here, one rail requires 1V±3% accuracy with < 30mVpp of noise (DC-20 MHz BW), and some other rail demands 1V±3% and <10mVpp@20MHz BW.

author: Tjuurko
author_rank: Regular Contributor
timestamp: October 21, 2020, 04:19:58 am
content: The first problem will be in providing a low total resistance of the "wire + DC load".For such a source, this resistance should be no more than 30 mΩ.

author: Berni
author_rank: Super Contributor
timestamp: October 21, 2020, 04:55:39 am
content: The way to do that is to add an additional 30A lab power supply in series to generate extra dropoff voltage for the dynamic load, this lets electronic loads reach 0mOhm apparent resistance. Or even let the load "push" current trough a 0V source(ie a piece of wire)Proper electronic loads have separate voltage sense wires to allows you to bypass and ignore the voltage of that extra series helper PSU while using it to help push current trough the load. The manual for the electronic load will likely explain how to wire this up.
Which oscilloscope should I keep? - Page 1
Forum section: electronics / testgear

author: Brogden
author_rank: Newbie
timestamp: October 15, 2020, 09:00:02 pm
content: I'm looking at removing either a Hameg HM605 or a Hitachi V-695 from my classroom workbenches (need the space for new Siglent sds1202x-e). Which of the two should I keep? What's the age range of the Hitachi? Thank you for any opinions or information.

author: tautech
author_rank: Super Contributor
timestamp: October 15, 2020, 09:18:00 pm
content: Welcome to the forum.IMO the Hameg.

author: Brogden
author_rank: Newbie
timestamp: October 15, 2020, 09:25:39 pm
content: Thank you. I was leaning that way for the component tester.

author: rvalente
author_rank: Frequent Contributor
timestamp: October 16, 2020, 02:47:18 am
content: Hahah sorry to say but Hamegs are awful to stare at and philips gets the 2nd horrible design prize.

author: george.b
author_rank: Frequent Contributor
timestamp: October 16, 2020, 03:14:23 am
content: I'd keep the Hitachi. I think having a readout function is more useful than the component tester (sounds pretty gimmicky to me tbh).Quote from: rvalente on October 16, 2020, 02:47:18 amI quite like my PM3055 :/

author: rvalente
author_rank: Frequent Contributor
timestamp: October 16, 2020, 01:11:44 pm
content: The PM3055 from "fluke" has a better looking, the brown PM3055 from philips was horrible. I own a PM6303, argh, terrible looking

author: David Hess
author_rank: Super Contributor
timestamp: October 16, 2020, 02:14:07 pm
content: I would keep the one which has the brighter and sharper CRT, which is probably the Hitachi.

author: battlecoder
author_rank: Regular Contributor
timestamp: October 16, 2020, 03:07:24 pm
content: I would also keep the Hitachi. I agree with cursors and readouts being more useful than a component tester (at least for regular oscilloscope use).

author: graybeard
author_rank: Frequent Contributor
timestamp: October 17, 2020, 12:18:02 pm
content: I would keep the one with the best focus and brightest trace.

author: Brogden
author_rank: Newbie
timestamp: October 20, 2020, 03:43:08 pm
content: Thank you all for the responses. You've given me a lot to think about.
Feel about 87.5% about my Siglent purchase - Page 1
Forum section: electronics / testgear

author: tkamiya
author_rank: Super Contributor
timestamp: October 19, 2020, 10:29:45 pm
content: Ya, I should have resisted....

author: LootMaster
author_rank: Regular Contributor
timestamp: October 19, 2020, 10:32:52 pm
content: Maybe you should round those numbers to 0%,50%, or 100%?

author: tkamiya
author_rank: Super Contributor
timestamp: October 19, 2020, 10:34:06 pm
content: Why would I want to do that? I want PRECISION!

author: LootMaster
author_rank: Regular Contributor
timestamp: October 19, 2020, 11:39:23 pm
content: Yeah but... I just don't think people share your opinion and find it interesting, sorry. Maybe you are not that interesting?Its just not extreme enough, quite boring in fact.Maybe next time. I don't think this will be a meme.

author: tkamiya
author_rank: Super Contributor
timestamp: October 20, 2020, 12:13:35 am
content: That's true. It's just garden variety ME....

author: jjoonathan
author_rank: Frequent Contributor
timestamp: October 20, 2020, 12:21:28 am
content: We have volt-nuts and time-nuts, I suppose it was only a matter of time before we saw opinion-nuts. Three significant digits is certainly an improvement on the status quo!

author: tkamiya
author_rank: Super Contributor
timestamp: October 20, 2020, 12:26:12 am
content: How about just nuts? Non discriminating, gender neutral, very opinionated, generic nuts. I'm a metric nut though.

author: tkamiya
author_rank: Super Contributor
timestamp: October 20, 2020, 12:39:05 am
content: Pending moderation.... 3...2...1 <poof!>

author: 0culus
author_rank: Super Contributor
timestamp: October 20, 2020, 12:40:30 am
content: Quote from: tkamiya on October 20, 2020, 12:39:05 amI, for one, am enjoying this immensely...trolling the troll is usually not a great course of action, but this is too funny.

author: tkamiya
author_rank: Super Contributor
timestamp: October 20, 2020, 12:44:44 am
content: Harmless fun.... these days, we all need to relax and laugh for no reasons what-so-ever.... Sacrificing a troll is a small price to pay.

author: ElectronMan
author_rank: Regular Contributor
timestamp: October 20, 2020, 04:20:40 am
content: Quote from: LootMaster on October 19, 2020, 10:32:52 pmI had a Cyrix processor that hated floating point too.

author: uski
author_rank: Frequent Contributor
timestamp: October 20, 2020, 04:36:46 am
content: Let me hack your percentage to 100% and it will be fineOh wait, that's illegal, police is coming !

author: tkamiya
author_rank: Super Contributor
timestamp: October 20, 2020, 05:26:28 am
content: Yeah... you'll need to buy a license for that.

author: TurboTom
author_rank: Super Contributor
timestamp: October 20, 2020, 01:05:41 pm
content: Quote from: tkamiya on October 20, 2020, 12:26:12 am... I want Mars and Snickers...

author: shakalnokturn
author_rank: Super Contributor
timestamp: October 20, 2020, 01:14:04 pm
content: No those are infamously branded "snack size" nuts. Not generic enough...

author: tkamiya
author_rank: Super Contributor
timestamp: October 20, 2020, 01:27:35 pm
content: Who are you calling short?
Audio spectrums - Page 1
Forum section: electronics / testgear

author: hamster_nz
author_rank: Super Contributor
timestamp: October 22, 2020, 09:10:33 pm
content: I'm not sure the right place to put this, so here goes...I'm working on crufty software to use a higher quality sound card as an audio test interface, for my use only. I know other software exists that I could use, but a man has to have a hobby. I also what to have repeatability in the testing - so I know things will be exactly the same when testing on different days. I'm not really after a GUI, just an objective set of tests I can run to measure performance of the unit under test under different conditions.I've got programming ALSA all sorted, and for this current setup I play a 1000kHz tone at 48kHz, 16-bit, while also recording line in. (as I am currently using my development laptops's onboard 16-bit CODEC for now). I've got a loopback cable from out to input.The noise is about +/- 14 counts RMS, the signal +/-30.000 counts. I've got my basic analysis going - collecting 4800 samples (0.1s) and running an DFT on them (no FFT yet, as I'm just playing around and performance isn't important). With 0.1s of data each DFT bin ends up to be 10Hz.A plot of the results is attached.So... a long build up to the question.As you increase frequency resolution (longer data set, longer DFT, more bins in the result), I *assume* the noise per bin reduces too - after all, the total power has to remain the same. On a graph the noise floor will get lower.How do I standardize the measurement so I get roughly scale-invariant metric of noise, regardless of DFT length?Do I divide the bin's power by the width in Hz to get "power per Hz"?Do I just remove the test tone bin, and calculate the power of the rest (I guess that leave THD+noise)?Am I overthinking this?Or maybe more importantly, are my assumptions wrong?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 22, 2020, 09:53:55 pm
content: Picking out the signal bin leaves you with THD+N, if that's what you're after then there you go.Use Parseval's theorem to calculate total power.Dividing a bin by its width gets you noise per BW, yes; though you don't know if this is signal or what (a good guess that the prominent peak is signal, of course). You'd have to average over all the baseline to get an overall picture of noise -- which, again, it's not an arithmetic average but an RMS one, in other words Parseval's theorem.Tim
HP 34401A parts wanted - Page 1
Forum section: electronics / testgear

author: iXod
author_rank: Frequent Contributor
timestamp: October 19, 2020, 07:40:33 pm
content: Had my meter repaired and discovered it's missing support clips on the input banana jack blocks.(i STILL can't figure out how to insert an inline image...)The black bit above the red input block. Need 2.Thanks.

author: bdunham7
author_rank: Super Contributor
timestamp: October 19, 2020, 09:22:00 pm
content: Available from HPAK:https://www.keysight.com/my/partDetail/34401-45012

author: tautech
author_rank: Super Contributor
timestamp: October 19, 2020, 09:33:08 pm
content: Quote from: iXod on October 19, 2020, 07:40:33 pmThat part of the forums SW is broken and has been for a few months after Dave installed a patch in an attempt to fix another forum bug.Use the Insert Image icon and place the thumbnail's URL between the img flags.Quite straightforward with a post Edit where thumbnails are still accessible to copy their URL from.Quote someone's post and examine the syntax of how it's done.
Feel good about my Siglent purchase  - Page 1
Forum section: electronics / testgear

author: apple ][
author_rank: Newbie
timestamp: October 19, 2020, 03:48:07 pm
content: I just purchased a Siglent SDS1104X-E during the amazon prime day flash sale, arrived the next day. And I have till the end of January to return it if there are problems. Thanks to the great advice on eevblog I easily enabled the "oscillation overthruster". Also thanks to Tautech for being available for support questions !!( now may I purchase the SLA1016 hardware for MSO operation for $150 please?? )

author: tautech
author_rank: Super Contributor
timestamp: October 19, 2020, 08:20:14 pm
content: Welcome to the forum.Hope you're enjoying your new scope and all its capability.Yeah the MSO HW isn't priced favorably however I don't know what brand ever offers these options for cheap.
Voltcraft Component tester for scope - Page 1
Forum section: electronics / testgear

author: Martin72
author_rank: Super Contributor
timestamp: September 27, 2020, 07:48:13 pm
content: Hi,https://www.conrad.de/de/p/voltcraft-i-v-curve-tastkopf-isoliert-1301290.htmlQuoteI find the price attractive for a ready to use x-y component tester - What are your opinions about ?Or experiences with it ?Martin

author: egonotto
author_rank: Super Contributor
timestamp: September 27, 2020, 10:30:15 pm
content: Hello,In my feeling it is too expensive. 9Vrms with 2mArms with unknow fequency.Best regardsegonotto

author: bob91343
author_rank: Super Contributor
timestamp: September 28, 2020, 04:43:14 am
content: I agree, this is too simple to cost so much. Just read about the octopus for instance. You can build your own easily. In fact you can built it whenever you want it and take it apart when done.

author: Ringmodulator
author_rank: Regular Contributor
timestamp: September 28, 2020, 10:32:39 am
content: Just google "octopus curve tracer"Example Video:I got an older small 10MHz scope from hameg with ther integrated component tester funktion for less.Chris

author: Fretec
author_rank: Contributor
timestamp: October 19, 2020, 06:17:55 pm
content: Quote from: bob91343 on September 28, 2020, 04:43:14 am+1 quick, easy and cheap

author: kripton2035
author_rank: Super Contributor
timestamp: October 19, 2020, 07:27:30 pm
content: search for some used analog 20MHz or so scope, on any craiglist for less than $50 most of the timethey almost all contain such a component tester
Current sense resistor for Voltech mains breakout box - Page 1
Forum section: electronics / testgear

author: petemate
author_rank: Regular Contributor
timestamp: October 18, 2020, 08:15:29 pm
content: Hi guys, i'm thinking about replicating this mains breakout box:http://www.farnell.com/datasheets/1650902.pdfAs you can see, the box has the possibility of either using the internal sense resistor of the power meter or use its own 1 ohm resistor for low-power measurements. I am interested in replicating this feature. However, I am curious about the requred temperature tolerance of the resistor required. A 1 ohm resistor with 1A (the maximum allowed) through it should dissipate 1 W, obviously. But what about the resistance change caused by heating of the resistor? What I am concerned about is that basically every tolerance is multiplied by the mains voltage(230VAC), so a 1% change of a 1A current at 230VAC would change the power dissipated by 2.3W. That seems like quite a lot?I was thinking about using this ER58 resistor(https://www.te.com/usa-en/product-1-1623750-1.datasheet.pdf), which is what I have available. Its a 7W resistor, so there should be some overhead for disspiating 1W. The datasheet specifies max 60 ppm/decC, which I guess is fairly acceptable? I am a bit confused about the PPM value, since the temperature range isn't clearly defined. But am I correct in assuming that at 1 ohm at 25degC would cause a max deviation of 60ppm*50degC = 3mR at 75degC ?A 3mOhm change is equal to 0.3%, so that should reduce the error to 0.7W at full power. Thats still quite a bit, considering standby power measurements often deal in the 0.1W range. Do you guys know if special resistors are used and if so, what can you recommend?Thanks!Addition:I tried measuring the 1 ohm resistor over a period of 12 hours(overnight). It shows a variation of ~3.4mR(max-min). This is on both my keithleys. I assume the temperature control of the meter is as important as of the resistor under test?
adding Option 001 (6th digit) to HP 5221B - Page 1
Forum section: electronics / testgear

author: av500
author_rank: Contributor
timestamp: March 02, 2020, 06:00:53 pm
content: recently acquired a HP 5221B and now added the 6th digit to it (Option 001). Nixie tube courtesy of a German eBay vendor that had a tube for sale right at the day that the counter arrivedHP 1820-0092 and HP 1820-0019 ICs for reasonable money from a surplus vendor. The 1820-0016 is $$$, so kludged in a 74LS75, wiring up only the 4 bits to the nixie driver, not the inverted bits to the printer interface. the 7475 has an inverted polarity latch pin, so I added a 2N3904 with 10k base, 10k pullup to invert the latch signal

author: Cubdriver
author_rank: Unknown
timestamp: March 03, 2020, 06:05:14 am
content: Very nicely done!!-Pat

author: dgminala
author_rank: Contributor
timestamp: October 18, 2020, 03:15:06 pm
content: Thanks for the post. Where did you get the 1820-0092 from, and what did they cost? I'm trying to help a friend repair an HP 5216A counter with a bad driver IC.Thanks for the helpDave M

author: av500
author_rank: Contributor
timestamp: October 18, 2020, 04:28:25 pm
content: I ordered two of them for $10 each fromhttps://dsmcz.com/but they might have been the last ones, since they are not listed any more
Help needed with Fluke 8845A SCPI commands - Page 1
Forum section: electronics / testgear

author: ledtester
author_rank: Super Contributor
timestamp: October 16, 2020, 04:31:09 pm
content: I'm trying to control a Fluke 8845A via the serial port, and I'm having trouble making sense of the documentation in this manual:https://xdevs.com/doc/Fluke/8846A/8845a_8846a_programmersmanual.pdfSome simple commands I've tried work like (see page 36):*IDN?DISP ONDISP OFFSYST:VERS?but others don't, like:SYST:TIME?DISP ON:TEXT "Hello"Are these not supported on the 8845A?And then on page 38, the MEAS? command only works if I put the meter in Fluke45 mode.And these examples of page 39 don't work in either the 8845 or Fluke45 mode:MEAS:volt:ac? 10MEAS:diod? ONOn page 31 FUNC "VOLT:AC" works, but FUNC "CAP" doesn't.(of course - the 8845A can't measure capacitance.)I think I'm missing something basic here.

author: ledtester
author_rank: Super Contributor
timestamp: October 16, 2020, 08:59:21 pm
content: Ok - I think I've figured it out. What I was missing was putting the meter in remote control mode with SYST:REM.

author: alm
author_rank: Super Contributor
timestamp: October 18, 2020, 04:16:05 pm
content: Thanks for posting that update. I guess isis because it also supports GPIB. With GPIB the GPIB controller will assert Remote ENable whenever you send a command. Apparently for RS-232 this is an explicit operation you need to do.
Field Fox question for an owner (power supply) - Page 1
Forum section: electronics / testgear

author: akamomo
author_rank: Newbie
timestamp: October 20, 2020, 05:51:46 am
content: Hi!Picked up a used Field Fox and can't suffer for the $165 Agilent branded power adaptor if not necessary.... I see its 15VDC 4A, can someone tell me the dimensions of that connector so I can get a sane adaptor and get started with the new toy please?Thanks so much!

author: akamomo
author_rank: Newbie
timestamp: October 20, 2020, 06:10:47 am
content: newbie searches... think I might have found ithttps://www.eevblog.com/forum/testgear/u1620a-power-supply-specs/msg3058628/#msg3058628I believe this may work? 0950-5014 is certainly available used so seems worth trying.The Fieldfox is model N9912A btw if it wasn't clear... though fairly sure it's the same all models.Thanks again I'll still take any added info re a 3rd party adaptor sure to work.

author: TheSteve
author_rank: Unknown
timestamp: October 20, 2020, 07:34:52 am
content: Why not buy yourself the real thing -https://www.ebay.com/itm/293721061834I hope your fox has some good options installed.
RD6006W Power Supply shuts off, randomly - Page 1
Forum section: electronics / testgear

author: hpmaxim
author_rank: Regular Contributor
timestamp: October 14, 2020, 12:37:32 am
content: I bought an RD6006 several months ago and am using it to power an embedded computer in a parked vehicle.I have it plugged into an extension cord and configured to turn on the output upon startup. The supply is set for 12V/3A and the embedded computer typically draws 6-700mA.I have used this setup successfully for a while, turning it on/off by plugging or unplugging the extension cord into a receptacle on the outside of my house.The past few times I've tried this it worked fine for some time (5-60 minutes) and then the output shut off (supply was still on). If I enabled the output, it again worked fine for some time and then the output was disabled again.I'm using the recommended 60V supply and I do have the temp probe installed, it was inside the case. My only thought was maybe it touched something hot and responded by disabling the output? I have not yet been able to replicate it with the power supply in my house.Help?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 16, 2020, 11:46:48 pm
content: Check the OVP setting.

author: hpmaxim
author_rank: Regular Contributor
timestamp: October 17, 2020, 06:11:59 pm
content: Quote from: S. Petrukhin on October 16, 2020, 11:46:48 pmThanks for the response. I actually reached out to RD6006 and to my surprise, despite the language difficulties they were able to figure it out. I still don't understand it exactly, but apparently, the green terminal needs to be shorted to the black terminal. Apparently, it thinks it's trying to charge a battery and and a result of (something), if the green terminal isn't grounded it could think the battery is fully charged and shut off the power supply. This seems very weird, to me, but... I installed the short and haven't had a problem in a few days. If someone wants to try to explain that to me, that'd be great though.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 17, 2020, 06:30:08 pm
content: Quote from: hpmaxim on October 17, 2020, 06:11:59 pmIt is likely that the voltage divider at the input of the op amp or the op amp itself detecting the voltage of the connected battery is faulty. It is possible that there is some strong noise at the input of the battery charge. Maybe check damages or oxides on the PCB in the battery detection circuit.
Leader LBO-325 owners - Page 1
Forum section: electronics / testgear

author: brndn84
author_rank: Newbie
timestamp: October 17, 2020, 06:25:49 pm
content: I'd like to start off by saying I'm a beginner hobbyist, so please forgive my ignorance.I found a really nice LBO 325 on ebay that came with a carry case, sun shield and was in really great shape, the only thing I can get to work are the Illumination, intensity, focus, holdoff and trace controls. They all happen to use the same style pots that I can't seem to source the exact model of. They seem proprietary since they can be retracted or extended for use.I've attempted cleaning them with deoxit D5 and the show no change in resistance when checked with a meter.I suppose the upshot is I was able to focus the trace and lower the intensity using the appropriate trimmers inside the case, but that's not really ideal.This isn't a scope I plan to use all the time, I have a DS1054z, but I do want to get it fully functional.I'm hoping some d100 will clean up the pots a little better, short of that, does anyone with experience with this scope have any other suggestions?I should mention I also have a LBO-323 that's mostly a parts machine at this point and it suffers the same issue. I'm guessing these pots are commonly bad?
Help with oscilloscope ? - Page 1
Forum section: electronics / testgear

author: gabri.peic
author_rank: Regular Contributor
timestamp: October 15, 2020, 10:38:59 am
content: Hi everyone.I came a cross this old thing on my local site...https://www.njuskalo.hr/mjerni-instrumenti/osciloskop-hm-312-hameg-oglas-32437522Anyways i am looking for a cheap oscilloscope just to get me started mostly for repairing vintage TV s, amps and analog organs. Is this thing worth it it is only one channel but i really can't find anything better for these sort of prices here in Croatia (it is pretty hard to get test gear here for cheap...)What are your opinions on that thing ?Also i am a complete newbie with oscilloscopes and can someone point me in the right direction for learning to use this thing.Thanks in advance.

author: vk6zgo
author_rank: Super Contributor
timestamp: October 15, 2020, 11:26:35 am
content: You can do useful work with fairly basic Oscilloscopes, & the Hameg is a cut above "basic", even just having one channel.

author: tggzzz
author_rank: Super Contributor
timestamp: October 15, 2020, 12:27:50 pm
content: A cheap old scope is better than nothing,providedit is working correctly.You do not want an oscilloscope that is faulty.That scope may or may not work. You need to see a sweep across the whole screen, it displaying a signal, and it triggering on the signal.

author: gabri.peic
author_rank: Regular Contributor
timestamp: October 16, 2020, 01:56:44 am
content: Thanks for the help i will think about it. I will keep an eye out for maybe better deals. Who knows maybe for a little more money i can get a dual channel ... I found one more...https://www.njuskalo.hr/mjerni-instrumenti/hameg-20mhz-oscilloscope-hm-203-4-oglas-31342194Also on this one guy says that price is not fixed so i can probably lower it...I am not in a rush I am just looking for now.Thanks.

author: bob91343
author_rank: Super Contributor
timestamp: October 16, 2020, 02:20:38 am
content: That looks good. My last two or three scopes I got free so the price shouldn't be too much.

author: rvalente
author_rank: Frequent Contributor
timestamp: October 16, 2020, 02:37:53 am
content: I do not know these hamegs but I would suggest to look for tek 22xx series, they're a very bullet proof and easy to repair.Since you're in europe, look for philips or even, telequipment

author: george.b
author_rank: Frequent Contributor
timestamp: October 16, 2020, 03:23:29 am
content: Quote from: gabri.peic on October 16, 2020, 01:56:44 amThat one is a lot better than the first one.

author: gabri.peic
author_rank: Regular Contributor
timestamp: October 17, 2020, 09:19:25 am
content: Thanks for the help. I will think about it. Maybe i will wait until after Christmas because i am not in a rush but i will see.
Maynuo M9712 zero current measured value (output off) - Page 1
Forum section: electronics / testgear

author: manupthehills
author_rank: Contributor
timestamp: October 15, 2020, 11:57:22 pm
content: I own an M9712 electronic load that I'm about to calibrate (adjust).The main board doesn't look too clean and I measure 32uA when 12V are applied to the input. This current is measured when the output is off.Not sure if this is a normal value for this instrument or if this is the result of the dirty PCB...Anyone owning this model can please run the same measure and reply with the value?Thanks

author: Tjuurko
author_rank: Regular Contributor
timestamp: October 16, 2020, 09:01:54 am
content: And if you turn off the voltage measurement circuit?MENU -> SYSTEM SET -> TERMINAL SET -> BACK

author: Pinkus
author_rank: Frequent Contributor
timestamp: October 16, 2020, 02:13:37 pm
content: Same with my M9712: I measured 33µA. Even if the unit is fully switched off (main power) it takes 27 µA.... and mine is definitely clean inside!

author: Tjuurko
author_rank: Regular Contributor
timestamp: October 16, 2020, 03:36:51 pm
content: In my case (M9812), all parasitic consumption goes to the voltage measurement circuit (R=365k).60V - 164 µA50V - 137 µA40V - 110 µA...10V - 27.2 µAWhen switching to the rear panel (no wires connected to the rear panel), the consumption is 0.

author: manupthehills
author_rank: Contributor
timestamp: October 16, 2020, 05:10:14 pm
content: Thank you guys! That saved me a lot of work.I also measured the input current at the front terminals in the other two configurations:- 12V front terminals: 32.6uA- 12V rear terminals: 120nA- 12V mains disconnected: 27.7uA
HP 43113B pulsed event timer - Page 1
Forum section: electronics / testgear

author: Raindog
author_rank: Contributor
timestamp: October 13, 2020, 02:23:47 am
content: Greetings all, does anyone out here know where I can find some information on this instrument? There is limited info on the web and I cannot seem to find it in HP catalogs from the late 70's, yet. I picked one up off of eBay for $20 and would like to acquire some sort of operating / service manual information on this unit.Thanks in advance...

author: 0culus
author_rank: Super Contributor
timestamp: October 13, 2020, 02:52:15 am
content: I can't find anything on it either, and I have almost all the catalogs on my shelf. There is a non-zero chance this is a non-catalog item made for military customers. Or I'm just looking at the wrong catalog.

author: Raindog
author_rank: Contributor
timestamp: October 16, 2020, 03:32:51 am
content: Well thanks for looking. I don't have any of the "physical" catalogs but I did download several of them and cannot find this thing in any of them. But you're probably right about this being a custom built unit for the military, I had been thinking the same thing.Thanks again.
Mustool MDS 2112P Review and Teardown. - Page 1
Forum section: electronics / testgear

author: TheDefpom
author_rank: Frequent Contributor
timestamp: October 10, 2020, 08:53:00 pm
content: I did a couple of videos on this unit, it is actually not too bad, thought I would share this with the rest of you.The main board is marked as SDS1102 Rev1.2, the Owon SDS1102 uses basically the same PCB, let me know below if you know of any others that are the same.

author: jebem
author_rank: Regular Contributor
timestamp: October 15, 2020, 04:42:31 pm
content: That is a nice teardown, showing the analog vertical amps for the first time on this modal. Thank you fir sharing it.Although I almost sure the other side of those three PCB's also contains active components.I was looking into my unit the other day and I do not see the ADC chip(s) anywhere on the main PCB upper layer, so they must be underside.The power supply PCB is doubled side, as the rectifiers (both AC input and AC output) are not located on the upper layer.The PCB for the controls also has a USB port, and I do not see the USB controller in the main board, so it should be on the underside of that board.So far, nobody doing teardowns on this low cost model is taking the time to tear it down to the last PCB.When I have the time and mood to do it, I will share my findings.
What's a good used value on a Agilent N3300A - Page 1
Forum section: electronics / testgear

author: ptrn
author_rank: Contributor
timestamp: October 04, 2020, 06:06:46 pm
content: Hi allI've been offered to buy a used Agilent N3300A DC electronic load frame with a N3302A module installed (60V/30A/150W). The condition looks to be good and everything is supposedly working. I haven't received a price for it yet though, what's a fair price to pay for this?Thanks for all insight

author: nctnico
author_rank: Super Contributor
timestamp: October 04, 2020, 07:13:11 pm
content: I'd pay less for it compared to a Chinese 150W load. Be aware that is is a rather noisy (loud fans) unit.

author: Fretec
author_rank: Contributor
timestamp: October 13, 2020, 12:01:22 am
content: Quote from: nctnico on October 04, 2020, 07:13:11 pmBy itself, I would absolutely prefer it to any Chinese 150W unit, but the downside is that it's large, heavy and as said loud. If you have the space for it and the price is ok, go for it, but for home use I would kinda see it as overkill.And as someone who has quite a collection of old test gear, I can tell you that you get fed up with fan noise after a while... I ended up modifying most of my stuff with quiter fans, but out of the box it can get pretty bad if you have a bunch of them running.

author: Golds
author_rank: Contributor
timestamp: October 14, 2020, 01:08:26 pm
content: Pay attention to the signs of aging and dampness of equipment that has not been used for a long time .This is what you have to face.

author: Ordinaryman1971
author_rank: Frequent Contributor
timestamp: October 14, 2020, 02:31:29 pm
content: Do you need to have so many channels or to dissipate so much energy into something... if you do, I would say go for it.This is rock solid equipment with great expandability, you can get it with one module but have total of.. 6 installed, there are different plugins for those, some of them use double space.If the price is right I would say, you can't go wrong with this frame.The frames go for about $1k, modules it's a different story. I've got one for free..., the other one came with the frame.And... it will match all your other HP gear.
RSPro/Isotech IDM72, APPA 71/72/73 - Service manual or calibration points. - Page 1
Forum section: electronics / testgear

author: TheBay
author_rank: Unknown
timestamp: October 18, 2020, 12:14:21 pm
content: I'm looking for a service manual or some information regarding the calibration of one of these meters.I basically need to know what potentiometer does what as it's not in any of the manuals, I need to calibrate the DC Voltage range.I sent APPA an email but they just told me to contact the retailer and RS just offer their own in house calibration.There is one here that I never use as the DC voltage range is off by a bit, it would be interesting to see how well I can calibrate it as it seems quite a well put together meter.Thanks.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 18, 2020, 03:33:23 pm
content: if the chipset are known, find the datasheet for them and search their aplication notes, you could find some info thereIf the meter has trimpots, measure them on each pins, the center / wiper versus the 2 other pins, note their values before twiddling them
Are Tektronix TDS3012B & TDS3012C power supplies swappable? - Page 1
Forum section: electronics / testgear

author: wd5jfr
author_rank: Regular Contributor
timestamp: October 13, 2020, 11:11:32 pm
content: The title says it all.Anyone with first hand experience let me know.Also does anyone have one for sale or know where I can find one?ThanksHank
Der EE DE 5000 Warranty? - Page 1
Forum section: electronics / testgear

author: harry
author_rank: Newbie
timestamp: October 12, 2020, 07:59:03 pm
content: What is the Warranty on the Der EE De 5000?The one I just received has no warranty card.There is no mention of warranty on the Der EE web site.I paid with a credit card, thinking that if there's a problem the card companies extended warranty program would cover it.But the credit card extended warranty program requires that their be some sort of original warranty.So... does the Der EE De 5000 come with a warranty?

author: Fretec
author_rank: Contributor
timestamp: October 14, 2020, 10:57:40 am
content: Have you tried contacting DER EE directly? They should be able to help with that.
Wavetek 2510A - Page 1
Forum section: electronics / testgear

author: AndreH
author_rank: Newbie
timestamp: October 14, 2020, 06:37:54 am
content: Hi allI have the Wavetek 2510A Synthesized Signal Generator (1.1GHz). She worked perfectly until about a week ago - on switching on the unit the LCD screen flashes with some parts of the screen only flashing half the screen. Mainly gibberish on the screen. Nothing happens until I touch pin 36 (PB0) with my multimeter probe (or finger) on the 6805 processor then she suddenly springs to life and starts the SELF CHECK sequence and stops at 80. The screen also returns to normal - no flashing gibberish. If I now turn the freq knob it then proceeds to r4.0 (I'm not sure if this is an error code) and remains at r4.0On three ocassions she completed the self check and went into my previous freq/level settings with everything copacetic. It outputted the correct freq etc. In other words the fault cleared whilst localising. Since then the fault never cleared again - it continuously stops at sequence 80, only after touching pin 36. I don't have the service manuals and did the following checks;- visual inspection- probed for possible dry joins/loose connectors- checked voltages on the various voltage regulators (78xx and 79xx). All checked out fine.PS: The fault will be difficult to locate without the service manual. I searched the net for a service manual but to no avail. If you know of where one is available for download, do let me know.Thanking you in advanceAndreH
banana plug with thumbscrew adapter - Page 1
Forum section: electronics / testgear

author: electrolust
author_rank: Unknown
timestamp: October 05, 2020, 09:19:21 pm
content: What's this adapter called? Neither Pomona nor Caltest seem to have such a beast in their catalog, and I can't find it via search.thanks

author: SilverSolder
author_rank: Super Contributor
timestamp: October 06, 2020, 12:00:41 am
content: What does it plug in to - a BNC connector?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 06, 2020, 12:17:49 am
content: Hi,The instrument is a Tektronix model 130 LC meter.Link:https://w140.com/tekwiki/wiki/130The adapter you are looking for is PL259 to binding post.You will probably have to make one or use a PL259 to BNC and BNC to binding post.Jay_Diddy_B

author: Electro Fan
author_rank: Super Contributor
timestamp: October 06, 2020, 02:07:49 am
content: Maybe too klugey but looks like you could go PL259 to BNC to banana.https://h5.aliexpress.com/item/4000199824208.html15 and 2 ?

author: electrolust
author_rank: Unknown
timestamp: October 06, 2020, 05:17:25 pm
content: Thanks. The photo came fromhttps://www.nutsvolts.com/magazine/article/build_your_own_electronics_test_fixturesNow that I take a good look at the Type 130, what a beautiful piece of vintage gear.

author: tooki
author_rank: Super Contributor
timestamp: October 06, 2020, 08:47:41 pm
content: Quote from: electrolust on October 05, 2020, 09:19:21 pmProbably because that’s not a banana plug. As others said, it adapts to binding posts, whichacceptbanana plugs.

author: mansaxel
author_rank: Super Contributor
timestamp: October 06, 2020, 08:58:43 pm
content: Quote from: tooki on October 06, 2020, 08:47:41 pmOTOH, the PL259 is known as the "screened banana plug" among those who rightly find it less useful as a RF connector. I'm only using it on radios where I have not yet converted to BNC, TNC or N.

author: tooki
author_rank: Super Contributor
timestamp: October 08, 2020, 12:15:29 pm
content: Interesting! I’ve never heard it referred to as that.I’m surprised it’s found much any more, given that according to wiki, it’s not even defined by a standard!

author: commongrounder
author_rank: Frequent Contributor
timestamp: October 09, 2020, 11:42:36 pm
content: I’ve always called those PL259s “UHF” sockets. They used to be used on old video recorder video I/O and oscilloscopes, among other things. My Leader AC millivolt meter uses them. The center socket is banana pin sized, and Leader cleverly spaced that socket 3/4 inch from the banana ground socket to allow a dual banana plug to be inserted. I have BNC adapters on them. See attached picture.

author: Fretec
author_rank: Contributor
timestamp: October 14, 2020, 01:18:04 am
content: https://www.ebay.com/c/1123704050This?
Adapter to allow conversion from non-safety banana to safety banana? - Page 1
Forum section: electronics / testgear

author: petemate
author_rank: Regular Contributor
timestamp: October 12, 2020, 11:49:44 pm
content: Hi guys,I remember having seen some adapters that would allow you to convert a non-safety(non-shrouded) banana connector to a safety banana connector(shrouded). It was a product intended to update old test equipment so that it would meet new regulations. But I can't for the life of me find the item in question. I believe it may have been purchased from Farnell, but i'm not 100% certain.Basically, it was a non-shrouded banana plug(male) converting to a shrouded banana socket(female). The male plug was split in four lengthwise and in the socket "hole" there was a small screw that when turned would move down into the plug and push apart the four pieces of the plug. You would push the adapter into a non-safety socket, turn the screw and have a compliant safety banana connector. Only annoyance would be that the connector would now extend quite a bit further out than the original connector.Rings a bell to anyone?Thanks!

author: srb1954
author_rank: Super Contributor
timestamp: October 13, 2020, 12:24:34 am
content: Quote from: petemate on October 12, 2020, 11:49:44 pmI got some from RS Components many, many years ago. Part numbers 404-272 for red and 404-317 for black.Not sure if these are still available.

author: VK5RC
author_rank: Unknown
timestamp: October 13, 2020, 02:32:43 am
content: Ebay seller f-t-2000 has them for 4$/pair, I have bought quite a bit of stuff from him over the years and found his stuff of good quality (not high end Pomona) but of good priceRob

author: Hydron
author_rank: Super Contributor
timestamp: October 13, 2020, 08:36:21 am
content: Stäubli A-SLK4Conrad has them (I'm sure among others):https://www.conrad.de/de/p/staeubli-a-slk4-uebergangsstecker-stecker-4-mm-buchse-4-mm-rot-1-st-731484.htmlhttps://www.conrad.de/de/p/staeubli-a-slk4-uebergangsstecker-stecker-4-mm-buchse-4-mm-schwarz-1-st-731468.html

author: petemate
author_rank: Regular Contributor
timestamp: October 13, 2020, 07:44:09 pm
content: Quote from: Hydron on October 13, 2020, 08:36:21 amThank you! Those are exactly the ones!

author: Hydron
author_rank: Super Contributor
timestamp: October 13, 2020, 08:21:56 pm
content: You're lucky - I found them recently while looking for something different (albeit banana plug related) so they were easy to find in my browser history. Glad I could help.