hybridfree/eevblog-posts huggingface dataset:
Laser Power Supply / Circuit ID - Page 1
Forum section: electronics / testgear

author: SpringHalo
author_rank: Newbie
timestamp: September 23, 2019, 11:59:01 pm
content: Digging in the e-waste bin at work I found a nice piece of kit. It's missing the main controller board so I can't test much out, but I'm very curious as to how the circuit works and what it's used for.Initial analysis shows 220v input, full bridge rectified into ~300VDC and sent over to the three identical PCBs in series with huge ICs under them that span the width of a hefty heatsink. The huge copper bus-bars indicate a good few amps are being dealt with, but not being able to see the ICs themselves due to soldered rivets makes this hard to decipher.The label inside says CS241 13V/80A, so I assume the 300V is being stepped down, but the lack of inductors or large ceramic capacitors rules out a switching supply. The huge heatsink and dual 60mm fans makes me think it might be some sort of linear supply for lower noise. Is there anyone that recognizes this?
HPAK branding - 34401A - Page 1
Forum section: electronics / testgear

author: artag
author_rank: Super Contributor
timestamp: September 22, 2019, 08:35:18 pm
content: Does someone here have an Agilent or Keysight branded 34401A ?If so, can you tell me whether the SCPI *IDN? command reports it as HP, Agilent or Keysight ?

author: Kosmic
author_rank: Super Contributor
timestamp: September 22, 2019, 09:36:55 pm
content: Got an Agilent branded 34401a. Here's the answer to *IDN?Code:-> *IDN?<- HEWLETT-PACKARD,34401A,0,10-5-2

author: artag
author_rank: Super Contributor
timestamp: September 22, 2019, 10:01:29 pm
content: Thanks.Seems sensible, since after the rebranding they'd still want it to work with existing test applications

author: Macbeth
author_rank: Super Contributor
timestamp: September 22, 2019, 10:14:53 pm
content: Oddly the 34401A never had a serial number in it's *IDN? response, while almost every imitator does.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: September 22, 2019, 10:34:54 pm
content: This discussion has me curios, the Agilent 34461A has claimed industry exclusive only 100% drop in scpi compatible to the 34401. So what does *idn say?.I don't have one to test. I could see 2 possibilities, a software set compatibility mode which results in HP 34401 response or it always replies 34461A, in which case not really 100% compatible, LOL catch-22

author: mr.fabe
author_rank: Regular Contributor
timestamp: September 23, 2019, 04:44:45 am
content: Quote from: chickenHeadKnob on September 22, 2019, 10:34:54 pmOn a 34461AFor compatibility purposes, use SYSTem:IDENtify HP34401A to return:HEWLETT-PACKARD,34401A,<Serial Number>,ff.ff-pp.pp-mm.mm-gg.gg-bb-pphttps://literature.cdn.keysight.com/litweb/pdf/5991-2367EN.pdf?id=2334983
Do You use signal tracers now? - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: September 22, 2019, 06:36:32 pm
content: I see few old tube signal tracers with 3" speakershttps://people.ohio.edu/postr/bapix/Heath_ST.jpgBut why I never seen transistor signal tracers?Are you using signal tracers now?Any benefits vs scopes?

author: daqq
author_rank: Super Contributor
timestamp: September 22, 2019, 07:39:39 pm
content: QuoteNever have. I did use current tracer ( HP-547A ) to find out where my shorted power rail touched the GND though.QuoteCan't think of any beside the immediate audible feedback the technician gains and the built in test signal source.

author: Martin.M
author_rank: Frequent Contributor
timestamp: September 22, 2019, 07:49:07 pm
content: The signal Tracer comes from the time of the glowing radios.A Tube is a very high impedance input what you cannot destroy with high voltage.There is also a indicator tube what help you to see when there is a not modulated HF.
Kunkin KL283 - Page 1
Forum section: electronics / testgear

author: queennikki1972
author_rank: Regular Contributor
timestamp: September 17, 2019, 03:01:47 pm
content: Does anyone have the Kunkin KL283 or have found a review on it? I was just wondering if this is a OK brand for dc loads.https://www.ebay.com/itm/30A-Dual-Channel-DC-Electronic-Load-Adjustable-digital-LED-display-KL283-Adapter/371958986412?epid=893982552&hash=item569a7bb6ac:g:R8MAAOSw4gpbcjss:sc:FedExHomeDelivery!76116!US!-1

author: ledtester
author_rank: Super Contributor
timestamp: September 17, 2019, 03:36:00 pm
content: You'll find a couple of comments here:https://www.eevblog.com/forum/testgear/kl283-electronic-load/You can also troll through the aliexpress listings to see if anyone has posted any reviews (besides reporting that they got the product - translated from Russian)

author: J-R
author_rank: Super Contributor
timestamp: September 18, 2019, 07:28:53 pm
content: I have it, got it as a new return for $135 delivered, the fan is loud even when cold. I added temperature control which can require some motivation as the fan is hard to get at and there are two independent heatsinks to monitor with the single fan. I added some decent silicone leads. After that I've been happy enough with it.

author: queennikki1972
author_rank: Regular Contributor
timestamp: September 22, 2019, 01:09:24 pm
content: Im used to the loud, lol, i have my workbench in the same room as my server rack. Blade servers are pretty loud.
X-Y Mode Rigol DS1102D - Page 1
Forum section: electronics / testgear

author: GerryR
author_rank: Frequent Contributor
timestamp: September 21, 2019, 03:21:43 pm
content: I've attached a couple of pictures from an analog scope and the Rigol DS1102D in X-Y Mode. I was doing some performance checks on a sweep generator w/ markers that require using a scope in X-Y mode. A brief description of the setup involves taking the RF output into a demodulator and sending the demodulated output back into the generator's demod input. The X and Y outputs of the generator are then fed to the 'scope.The first picture is the analog scope (40 MHz Kenwood) with the markers (1MHz) turned on; no problems with the display. I decided to try it on the Rigol.Second picture is the Rigol. At 1 Msample the display is basically useless. You can slow the sample rate down to get a more consistent display, but it is still useless as it is just a maze of dots without much detail.Third picture is the Rigol with persistance on infinite (only two choices, off or infinite) the display is somewhat useful because the 'scope "fills in the blanks" so-to-speak, but not at all what I was expecting.Does anyone know if I am doing something wrong or is this the nature of the beast. I tried some Lissajous patterns and basically the same maze of dots, a terrible display except on the simplest of patterns.

author: wraper
author_rank: Unknown
timestamp: September 21, 2019, 03:30:11 pm
content: DSO generally suck at X-Y, especially older/cheap models with low capture rate/ high dead-time, not to be confused with sample rate.

author: GerryR
author_rank: Frequent Contributor
timestamp: September 22, 2019, 11:36:47 am
content: So, which of the "more expensive" digital 'scopes could do this in "analog fashion?"
Tektronix 1730 - what can I do with this? - Page 1
Forum section: electronics / testgear

author: tkamiya
author_rank: Super Contributor
timestamp: September 22, 2019, 04:57:46 am
content: I've recently acquired some NTSC station monitors, namely Tektronix 1720 and 1730. (vector scope and waveform scope respectably). I'm going to use 1720 as an x-y scope but what can I do with 1730? Can it be modded to do something else?
HP 54501A Timebase cal error - Page 1
Forum section: electronics / testgear

author: MarkC
author_rank: Newbie
timestamp: September 21, 2019, 02:53:27 pm
content: I recently found an old HP 54501A that had been left in a cupboard for 14 years. Unsurprisingly it did not start up and after some reading I realised the NVRAM was dead, changed the DS1230Y for a DS1235Y and it cals without error.Unfortunately, there is an error message of "failed interpolator cal" that will not clear and when you run self test, acq, timebase it fails with an error of 0000 0011 0000 1000Any ideas would be appreciated. Thanks.
What's the good cheap AC clamp meter these days? - Page 1
Forum section: electronics / testgear

author: cvanc
author_rank: Frequent Contributor
timestamp: September 22, 2019, 03:27:12 pm
content: So I want to get a clamp meter to read AC powerline draw on my bench. I don't need great precision but it would be nice to find something that can read idle current of a DUT (well below one amp) as well as a full 20A branch circuit. Bonus points if it's physically small. Any suggestions? Thanks.

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 22, 2019, 04:18:24 pm
content: ac and.... dc capable... make sure that...https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/
Pros and cons of safe oscilloscope probing methods? - Page 1
Forum section: electronics / testgear

author: scatterandfocus
author_rank: Regular Contributor
timestamp: September 21, 2019, 05:35:17 am
content: I have seen lots of discussion around here about safe probing using either a differential probe or an isolation transformer on the device under test. I have also seen mention elsewhere of the old school method of using 2 probes with the add function and inverting one of the channels. It also seems that in a pinch a voltage meter could be used to check for a difference between scope ground and the ground point of interest on the device under test before probing, and simply not probing where there is a significant difference.What are the possible issues with these various methods of probing? For example, I saw one mention that using the scope's add function for differential probing will be noisier than using a differential probe.

author: BravoV
author_rank: Super Contributor
timestamp: September 21, 2019, 05:51:17 am
content: An excellent application note for beginner from Tektronix on different measurements approach with an oscilloscope.Fundamental of Floating Measurements and Isolated Input OscilloscopesBrief summary :What are the Advantages & Trade-Offs for these type of measurements using the oscilloscope ?Isolated Input OscilloscopeDifferential ProbeVoltage Isolator"A minus B" (Two probes technique)"Floating" a Conventional Grounded ScopeDownload link ->http://info.tek.com/rs/tektronix/images/3AW_19134_2_MR_Letter.pdf

author: tggzzz
author_rank: Super Contributor
timestamp: September 21, 2019, 06:48:02 am
content: Quote from: scatterandfocus on September 21, 2019, 05:35:17 amHave a look at the references inhttps://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/
Tektronix AFG31000 2GS/s Arbitrary Function Generator Review, Teardown & Exp - Page 1
Forum section: electronics / testgear

author: Hugoneus
author_rank: Frequent Contributor
timestamp: September 16, 2019, 02:27:20 am
content: In this episode Shahriar reviews the new Tektronix AFG31000 Arbitrary Function Generator. The AFG31000 series with InstaView™ technology is the first high-performance AFG with built-in waveform generation applications, patented real-time wave monitoring, and a modern user interface. The instrument is capable of 2GS/s waveform generation up to 250MHz and 14-bits of vertical resolution. This review is organized as follows:00:08 – Introductions01:01 – Front panel, rear panel and instrument design03:44 – Detailed teardown, analysis, architecture and components17:30 – GUI overview and basic functions20:25 – Broadband FM modulation experiments23:55 – InstaView experiments with a non-linear impedance35:38 – Equation editor, waveform builder and advance sequencing51:21 – Concluding remarksYou can watch the video here: [52 Minutes]youtu.be/H3Y9JNOt3hA

author: Hugoneus
author_rank: Frequent Contributor
timestamp: September 17, 2019, 01:24:29 am
content: If you have GUI change requests, let me know.

author: rodpp
author_rank: Frequent Contributor
timestamp: September 17, 2019, 03:41:34 pm
content: Thanks for the great review, excellent as always.This AFG has similar specs to the AFG3000 series, but it is a big improvement regarding the GUI, the Instaview feature and the internal memory.

author: JxR
author_rank: Unknown
timestamp: September 21, 2019, 06:25:13 am
content: Thank you Dr. Shahriar, I always enjoy your in depth reviews.While I do think the AFG31000 is a cool device, I honestly would never consider it due to its physical size. I personally would rather they went with the standard half 2U form factor, and then had all this functionality available from a nice web interface. Desk space for me is just at too much of a premium to have an AWG the size of an oscilloscope. Although, I'm sure there are those that would appreciate the large screen and touch interface.Regardless, it was nice to see the unit in action. Hopefully they will improve some of the GUI aspects you pointed out.
FLUKE 2030A little printer problem - Page 1
Forum section: electronics / testgear

author: Martin.M
author_rank: Frequent Contributor
timestamp: September 21, 2019, 05:48:43 am
content: hello friends,any one of you own a 2030A little printer what is used for thermometer 2190A and so on?I think there is a repair to do, and I have no service manual.problem description.--------------------------------The little printer do nothing except when pressing the paperfeed button it forward the paper from the roll.Question: Is that allready , is there anything to setup or is there anything to repair?This situation is typical for a printer what have a defect paper sensor. The paperfeed button is to use for insert the paper in the printer slug when there is a fresh roll comming in, so this have to work also when no paper is in the printer = allready. But that little beast do not print anything, also in programming mode. Pressing Time + f have to answer as printed text the time stamp for setup, there comes nothing also. I have not seen any kind of paper sensor, only a little 10k ohms NTC is there, it may be used as overheat protection in the case, it is not in contact to the sheet.The only motor there is a stepper. It is OK bec. paperfeed works.The controller is a 8048 , it is OK bec. it runs also the paperfeed.This little printers do not use HPIB, there is a fluke specific port what is not directly compatible to the thermometer. But there is another device, the thermocouple scanner 2300A what can drive the printer, and of coarse reading the thermometer. So I made this Setup:2190A Thermometer (option 6, limits, no other) -> 2300A Thermocouple Scanner -> 2030A printer.The Thermometer is perfect working.The scanner is also working.The printer do nothing.The paper is fresh buyed and checked to be thermopaper, OK.I need that workingbtw. this is a restoration, I am not interested to buy another systemHow to continue?thank you.
Impressed with update speed of U1273A! - Page 1
Forum section: electronics / testgear

author: Terry01
author_rank: Frequent Contributor
timestamp: September 19, 2019, 09:30:04 pm
content: I've had my U1273A for a while now but never really used it day to day. I've started using it the last couple of days and boy is it quick!I'm impressed!

author: blacksheeplogic
author_rank: Frequent Contributor
timestamp: September 19, 2019, 09:54:53 pm
content: OK, thank's for sharing this in the general chat.

author: Terry01
author_rank: Frequent Contributor
timestamp: September 20, 2019, 11:55:25 am
content: How do you mean?

author: BravoV
author_rank: Super Contributor
timestamp: September 20, 2019, 02:01:36 pm
content: Reporting to mod to move to test equipment

author: rsjsouza
author_rank: Super Contributor
timestamp: September 20, 2019, 03:04:53 pm
content: It is impressive indeed. When I used to see their fast update models in the store (U123x, U125x, U127x), I thought it would give me a heart attack but nowadays I am much more used to it.Their flagship U1282A is a tad slower (5 readings per second). Still good.

author: Terry01
author_rank: Frequent Contributor
timestamp: September 20, 2019, 03:16:10 pm
content: I don't know why I haven't noticed it before, it really is super quick like you say! I've had it for around a year and although it wasn't one of my "go to" meters I did still use it sometimes.I've gotten rid of a few meters that I used a lot more than the 1273A over the last couple of months so I am using the 1273A more and more now.I will be using the 1273A more now for sure! It's quite a feature packed meter too I have found as well.

author: rsjsouza
author_rank: Super Contributor
timestamp: September 20, 2019, 03:28:33 pm
content: Yes, that is one great meter for sure. I had many others that were also sold due the same reason as you: the amount of features and specs are quite difficult to beat on the U127x line - even the U128x fails to have as much useful features (at least to me).The only thing that annoys me is the beep at power on and at the keypresses - I love my meters to remain silent. The U128x is much more sensible in this aspect, although the beep is much louder. I wish I could have a setting for beep volume.

author: hgjdwx
author_rank: Regular Contributor
timestamp: September 21, 2019, 01:06:29 am
content: Its AC,DC dual display mode is just as slow.Its resistance autorange speed is not fast, not as fast as FLUKE187, not as fast as DT4282
Difference between the HP 6034A and the 6034L Power Supplies - Page 1
Forum section: electronics / testgear

author: HalFoster
author_rank: Frequent Contributor
timestamp: September 20, 2019, 02:52:19 pm
content: I have a HP 6034L but have been unable to find any documentation on what makes this different from the "A" model. Physically, the only difference i can see is that it has an additional two connection terminal strip on the rear with the terminals marked "OV" and "A3" but I have not been able to find anything about this model.TIA for any help,Hal
Accuracy calculation - Page 1
Forum section: electronics / testgear

author: JtroTechAB
author_rank: Contributor
timestamp: September 20, 2019, 11:01:56 am
content: Hello,The Accuracy and Resolution for one of the channels of Rigol DP832 is 0.05%+20mV & 1mV respectively.So for 10mV reading (set on the supply) what should it show on the display?I have done half calculation only, i.e 0.05% of 10mV is 0.005mV so the range would be 9.995mV to 10.005mV is it correct?but for further calculation i am not getting desired result. please explain.the document which i referred is as belowhttps://brianhoskins.uk/digital-multimeter-accuracy/

author: RoGeorge
author_rank: Super Contributor
timestamp: September 20, 2019, 11:37:51 am
content: 0.05%+20mV for 10mV means 10mV*0.05/100+20mV=20.005mV, so the end result will be-10.005...+30.005 mV

author: JtroTechAB
author_rank: Contributor
timestamp: September 20, 2019, 11:56:28 am
content: could you please explain this calculation. can we add 20mV directly?In case of multimeter accuracy, they denote like this xx%+-xx digitsso the digit part they add depending on the resolution.so that concept is still not clear to me whether to add directly or not?

author: RoGeorge
author_rank: Super Contributor
timestamp: September 20, 2019, 12:48:58 pm
content: The explanation was about what you wrote. You wrote "0.05%+20mV". If you wanted to say 20 counts, then you should have written "0.05%+20" or "0.05%+20 units" or similar.If it says 20mV then you add mV, if it says digits, then you add 20 units. It can be either way, mV or digits, depending on how the producer made the specifications.
User/Service manual request for protek p-2510 oscilloscope or similar - Page 1
Forum section: electronics / testgear

author: resistcircuitresist
author_rank: Contributor
timestamp: June 20, 2019, 08:28:58 pm
content: Just received my first oscilloscope. It is a protek p-2510 100mhz analog CRO. Can anyone help me locate the user or service manual. I have searched and called protek directly and they no longer have any manuals for these scopes.

author: resistcircuitresist
author_rank: Contributor
timestamp: June 21, 2019, 04:42:55 pm
content: BUMP

author: ulyanoff
author_rank: Contributor
timestamp: September 04, 2019, 04:56:24 am
content: Hello everyone! Also need service manual for Protek P-2510 (or P-2560). I have one oscilloscope for repair - trigger very bad work, intensity blinking etc. May be have any documentation, please help me.

author: JFJ
author_rank: Regular Contributor
timestamp: September 04, 2019, 01:43:00 pm
content: I believe that the Protek P-2510 is a re-badged Hung Chang 5510. This EEVblog repair thread may provide some useful information:https://www.eevblog.com/forum/repair/hung-chang-5510-oscilliscope-repair/Hung Chang oscilloscopes appear to have been sold under several other brand names, such as Beckman and Leader. If there are other brand versions of your oscilloscope, then the chances of finding a service manual will be increased.

author: ulyanoff
author_rank: Contributor
timestamp: September 11, 2019, 06:34:46 pm
content: Thank you very much ! Also I am find another name for this device - DYNATEK 8060, it looks exactly the same. Repair find -http://zelfbouwaudio.nl/forum/viewtopic.php?t=15402. but still there are no schemes anywhere ...

author: ulyanoff
author_rank: Contributor
timestamp: September 18, 2019, 11:44:31 am
content: The case helped - once in searching for and viewing a circuit on a Tenma oscilloscope, I came across a circuit 5510. At least it is so signed. Unfortunately, only two sheets, but this is better! I think this help for repairing everybody.p / s / My circuit exactly matches the wiring on the board!
BT Tester 301B Time Domain Reflectometer - Page 1
Forum section: electronics / testgear

author: downwind27
author_rank: Newbie
timestamp: September 17, 2019, 07:59:07 pm
content: We have one of these testers on our heritage railway. After years of storage it is now needed and of course it's not working - dead as a doornail. The batteries have been replaced and are OK. Does anyone have a schematic diagram or service manual for this item?
Need help with HP 8591A Spectrum Analyzer - Page 1
Forum section: electronics / testgear

author: e_glu
author_rank: Newbie
timestamp: September 16, 2019, 07:22:47 pm
content: Hi everyone!I've always dreamed of my own spectrum analyzer, and I got a HP 8591A quite cheap today.It's quite old, but clean and it works. Kind of.It has a strange curve from 9 to about 100 KHz with no input cable attached, and calibration does not fix it. Please see the photo below.Anywhere from 100KHz to 1.8GHz, everything is flat and fine.Any suggestions, what can this be and how to fix that?Thanks!Evgeny

author: rf-loop
author_rank: Super Contributor
timestamp: September 17, 2019, 06:42:51 am
content: Quote from: e_glu on September 16, 2019, 07:22:47 pmI think only what you need fix is your knowledge about what is SA and how it works.Think RBW filter shape. You use 3kHz RBW. Its width is 3kHz, and it means this width is -3dB from center top. I do not know just this model RBW filter shape factor but because it is full analog IF SA it may be example around 12:1 what means its width is 12x3kHz (36kHz (18kHz from center)) -60dB from top.What you see is mostly like 0 Hz "image" after 3kHz RBW filter.If you can (I do not remember sure this model), set start to 0Hz you see it more clear...(if you can set "negative" start freq, set example -20kHz.. you see this 0Hz (this is how SA work)This is good to read basic fundamentals about SA's:Spectrum Analysis Basics Application Note 150Keysight TechnologiesThis OLD AN-150 is nice to read also.Look page 13.Do you have more narrow RBW filter than 3kHz, I think there is also 1kHz?http://hpmemoryproject.org/an/pdf/an_150.pdf(there is also more :http://hpmemoryproject.org/news/an150/an150_page_00.htm)
TEK 577, fixture 177 help! - Page 1
Forum section: electronics / testgear

author: frantisek
author_rank: Regular Contributor
timestamp: September 19, 2019, 09:32:03 am
content: Hello! Does anyone please have this adapter for TEK 577, 177 fixture? I need a photo of the top, the cover I miss. Thank you in advance!https://photos.app.goo.gl/Ry5juHBoWuYmh9jj6

author: jonpaul
author_rank: Super Contributor
timestamp: September 19, 2019, 08:13:34 pm
content: Hello the Google photos required account sign-on, very insecure.See TekWiki for all 577/177 info and pix, manualshttp://w140.com/tekwiki/wiki/177http://w140.com/tekwiki/wiki/577Good luckJon

author: frantisek
author_rank: Regular Contributor
timestamp: September 20, 2019, 08:28:39 am
content: Thanks jonpaul! Login is safe, don't worry !! Of course, I was looking at the Wiki. I found 013-0103-00 which is very similar, it can be said that it is identical. But mine has only 5 pins and 0103 has 6 ... Because he lacks a cover with a description, I don't know the type and I was hoping someone would have it at home or work and take a picture of me.
HP 8552A repair - Page 1
Forum section: electronics / testgear

author: Martin.M
author_rank: Frequent Contributor
timestamp: September 15, 2019, 07:22:21 pm
content: I have a repair in the 8552A IF Plugin for Spectrum analyzer.Problem: there are 2 neon bulbs what are zener with 103 volts, 0,2 up to 3mA.I am searching for replacements, it have to be z 103v with low temperature drifting.For insiders: they are in the vertical deflection board, it`s the second from the backside.Martin

author: Martin.M
author_rank: Frequent Contributor
timestamp: September 16, 2019, 06:44:33 pm
content: done !a new ZZ1000 neon stabi (= 81V) in series with a BZX55C22 (22 volts zener) delivers 102,3 Volts (22°C),hair dryer blown to 50°C = 102,38 Volts. The spectrum analyzer likes that and is working.Martin
hp 8901b option 037 - Page 1
Forum section: electronics / testgear

author: retroware
author_rank: Contributor
timestamp: September 16, 2019, 01:23:53 am
content: I recently purchased a HP 8901B with the phase noise/adjacent channel power options 030, 033 an 035. What I really wanted this for was to measure phase noise for which I needed a unit with option 037. As far as I can tell the only difference between options 033, 035 and 037 are the IF filters that are fitted to to the A72 board. Mine has two murata filters: CFS455-C and CFS455-F. I was wondering if anyone has option 037 and would be willing to let me know what filters are installed on the A72 board.Thanks for any help.
HP 4145A semiconductor parameter analyser software - Page 1
Forum section: electronics / testgear

author: Tandy
author_rank: Frequent Contributor
timestamp: September 12, 2019, 07:15:08 pm
content: I picked up a HP 4145A that has a 5.25" floppy drive with the system on it, a couple of things spring to mind...I wonder if anyone else has one and what software version you have and if anyone knows what the most up-to-date version was? Mine is revision A05.As the 4145A is pretty much the same machine, only with a 3.5" drive, it would be interesting to try the 4145B software on it.Ultimately I think I would like to replace the drive completely with a floppy emulator for reliability.

author: alm
author_rank: Super Contributor
timestamp: September 14, 2019, 07:13:45 pm
content: Not sure if the 4145B software will run on the 4145A: at least the disk format is different (LIF vs some proprietary format). However, it looks like this page contains instructions for setting up an emulator for the 4145A floppy drive on an mbed ARM Cortex M3 development board, and a disk image for use in that emulator:https://www.kitsune-denshi.net/equipment:hp4145a

author: picburner
author_rank: Frequent Contributor
timestamp: September 15, 2019, 01:47:21 pm
content: The 4145B, in addition to a different floppy disk drive, has more RAM than 4145A also.Even if you can run 4145B software on 4145A you risk running out of memory.However, the differences are seen comparing the two service manuals (probably with some modifications you can increase the ram).A long time ago I post the firmware of my 4145A (all eproms) on the KO4BB website (www.ko4bb.com).But no one post the 4145B firmware so there is no way to know if there are differences here too.

author: Tandy
author_rank: Frequent Contributor
timestamp: September 15, 2019, 05:19:54 pm
content: Thanks, I wonder if it really is a proprietary format on the 4145A or if Robert, who wrote that article wasn't familiar with LIF.Anyway with the difference in memory it might not be worth the effort. I had hoped that it would be possible to essentially turn the 4145A into a 4145B by replacing the drive with a floppy emulator and using the 4145B software. Given the age of it, it is probably best just to use it as it is and be on the lookout for one of the newer models like the 4155B. But still an upgrade from my Tektronix 575 Curve Tracer that is really more of a museum piece than of any real use today.

author: alm
author_rank: Super Contributor
timestamp: September 15, 2019, 06:43:18 pm
content: The 4145A uses a different sector format for its floppy disk from the 4145B, so there are will be differences in the firmware. No idea if they are compatible from a software point of view, but I see no reason for HP to have gone through the effort of maintaining compatibility.Multiple sources, likethis reddit post, mention that the 4145B is LIF, and 4145A is something else, so I'd say it's unlikely that the 4145A disk if LIF. Alsothis HP documentdescribes the 4145B as LIF, and 4145A as "unique".
uCurrent GOLD - issue on nA range - Page 1
Forum section: electronics / testgear

author: alexbn71
author_rank: Newbie
timestamp: September 15, 2019, 02:10:10 pm
content: Hi all,I assmbled myself a uCurrent GOLD but I have a strange issue during test (at 5V). With 47R(1W) and 47K I get exactly 106mV with the correct range selected (correct polarity on my multimeter).I have a strange issue with nA range and 50M resistor. The rading is unstable, oscillating between 70-100mV and the polarity is negative!what could cause this behavior?ThanksAlex

author: wraper
author_rank: Unknown
timestamp: September 15, 2019, 02:16:11 pm
content: If all parts are ok and properly assembled, it might be flux you used for soldering.

author: alexbn71
author_rank: Newbie
timestamp: September 15, 2019, 02:33:23 pm
content: After cleaning it with alcohol it seems more stable but this does not explain why the voltage is reversed on the output.The Input voltage has the correct polarity (+2.4mV) and the same polarity as 47R and 47K resistors... I don't undesrstand how can be inverted (-100mV) on the output, in nA range.

author: CDaniel
author_rank: Frequent Contributor
timestamp: September 15, 2019, 04:21:51 pm
content: If I look at the right schematic on nA range it doesn't have a shunt , so is relativily high impedance ( 10K ) and could be easily susceptible to mains or other fields influence .

author: wraper
author_rank: Unknown
timestamp: September 15, 2019, 05:22:39 pm
content: Quote from: alexbn71 on September 15, 2019, 02:33:23 pmWhat flux/solder you have used? With SMD it's impossible to completely clean without ultrasonic bath or other equipment which can reliably wash under the parts. I don't think -100mV is something extraordinary what cannot be caused by flux.Also if you made variant without capacitor in parallel to R7, in combination with LMV321 from certain vendors it may cause such issue. So if that's the case, try soldering 1uF ceramic cap in parallel to R7.

author: wraper
author_rank: Unknown
timestamp: September 15, 2019, 05:26:26 pm
content: Quote from: CDaniel on September 15, 2019, 04:21:51 pm10k resistor is a shunt.
Help with triggering setup - Page 1
Forum section: electronics / testgear

author: Harjit
author_rank: Regular Contributor
timestamp: September 15, 2019, 04:32:32 pm
content: I have an RTB2004 and need help setting up a trigger:The signal is a reset signal.Has a period of ten seconds.There are two reset pulses - let's say one occurs at t=0 and the second at t=920ms.I would like to trigger off of the second one and record waveforms immediately.I tried using delayed trigger but it can "lock" on the second reset pulse one and that doesn't give me the result I need.I've tried the Timeout Trigger but haven't gotten it to do what I need.What I think would work - but I don't have - is a holdoff with a count i.e. hold off for 1000ms (to get past the 920ms second pulse) and then trigger on the second rising edge.Thank you in advance!
EEVBlog 121GW Bench Stand (3D Printed) - Page 1
Forum section: electronics / testgear

author: snoozer
author_rank: Contributor
timestamp: September 15, 2019, 01:40:12 pm
content: Hi,thought I share my 121GW bench stand design in case others might find it useful. I wanted the angle a little lower then the original build in stand and since I am almost exclusively use it on the bench I also wanted it a bit wider to prevent accidental fall over. Have to add some rubber pads to the bottom to prevent it from slipping around but should be fine then.Thingiverse link:https://www.thingiverse.com/thing:3862923Fusion 360 link:https://a360.co/31q8WmWHave FuN!Jan P.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 15, 2019, 01:42:53 pm
content: Nicely done
Escort ELC-131D LCR meter for in circuit ESR test - Page 1
Forum section: electronics / testgear

author: a1976888
author_rank: Contributor
timestamp: October 15, 2014, 08:16:31 pm
content: Hi,I'm looking for a cheap meter to test capacitor ESR in circuit.I found a cheap old Escort ELC-131D LCR meter.Would it be good for my needs?Thanks!

author: HiTech
author_rank: Regular Contributor
timestamp: October 15, 2014, 08:34:19 pm
content: You actually have it or you found a used one to buy? Used on eBay I think they sell for way too high for what they are. Realize that the Escort has only two selectable test freqs, 1KHz being the highest.... so caps for switching supplies and high freq. amps will likely show inaccurate readings. Look for a used Peak Atlas or an Applent.

author: Lightages
author_rank: Unknown
timestamp: October 16, 2014, 02:58:01 am
content: The ELC-131D has a test out voltage of around 0.9V. It is not suitable for in circuit testing of capacitors.Edit: Actually mine goes just over 1V

author: a1976888
author_rank: Contributor
timestamp: October 16, 2014, 07:34:16 am
content: Thanks for yours answers!I will look for something else then. Probably a used der-ee-de-5000 or the really cheap $20 LCR ESR Transistor checker.I think that Peak Atlas or an Applent are way too expensive for me.

author: e4ch
author_rank: Newbie
timestamp: October 17, 2015, 09:46:09 pm
content: (replying to this old thread in case someone reads about this LCR meter) What did you finally end up with?I own one of these (Escort ELC-131D LCR meter) and I am very happy with it. Price in 1995 was around $450, so if you get it cheap and in perfect working condition, I would buy it. It's quite accurate. Yes, only two frequencies (120Hz and 1kHz), but that's enough for most cases. And I would not recommend measuring in-circuit anyway, if you want accurate results. In-circuit measurements are only for quick-testing if you look at a component that looks broken, but don't want to desolder it for a first test. If measurements are off, you have to desolder it anyway to verify that it's indeed broken.

author: yustech
author_rank: Newbie
timestamp: September 15, 2019, 12:58:33 am
content: I bought one USD25(used) without knowing the details. Its in great shape. Now I feel more happier after reading e4ch review. Thank you.
Tek TM501 - help me fix it - Page 1
Forum section: electronics / testgear

author: l0wside
author_rank: Regular Contributor
timestamp: September 10, 2019, 09:21:52 pm
content: Hi everyone,on my desk, I have two Tektronix TM501 (one 110V, one 220V version) and two AM503. The only working combination is the 110V TM501 and one of the AM503. Being in a 230V country, I would like to fix at least the 220V version of the TM501 to have a working current sensor unit.On the (defective) 220V unit, I have already replaced all large caps (C12, C22, C35). I have checked the bleed times when turning off, these are roughly in the range of 2V/s (no precise measurement, just voltmeter and some counting). So I guess the caps are in place, otherwise bleed times would be much faster.All voltages check out, but are slightly too high (25 VAC -> 27V, 33.5VDC -> 36.1V, 17.5VAC -> 20.3VAC, 25VAC -> 27.1VAC, 11.5VDC->13.1VDC). This can be partly explained by the 220V->230V conversion, which happened long after the unit was crafted. This does, however, not account for the full difference.The working AM503 lights up when plugged into the 110V unit, but not when plugged into the 220V unit with its overvoltage.I have also checked the two transistors (Q10 and Q12) by measuring their diodes. On the non-working TM501, all diodes give forward voltages in the 500...700mV range, which sounds plausible to me. Cross-check with the working unit shows that on the working TM501, Q12 does not seem to work. Strange. And no, I did not confuse the units.Any suggestions? I am pretty much out of my wits.Thank you from your TEA in the making

author: alm
author_rank: Super Contributor
timestamp: September 14, 2019, 07:27:17 pm
content: I don't expect the difference in (unregulated) voltages to be important. It would only increase dissipation slightly, something that is clearly not a problem if the plugin fails to power up with no load.To me the most likely suspect are the external pass transistors. They may not be shorted, but could still have degraded performance. If you take off the covers of the TM501 and AM503, you may be able to measure the power rails on the AM503 while plugged into the TM501. For example, if one off the 16V rails is low, that would point at the transistors in the mainframe.

author: texaspyro
author_rank: Super Contributor
timestamp: September 15, 2019, 12:01:01 am
content: Be aware the the pass transistors in some of the TM50x mainframes have non-standard pinouts...
UNI-T UT603 vs DM4070 (lcr meter) - Page 1
Forum section: electronics / testgear

author: gg64
author_rank: Regular Contributor
timestamp: September 13, 2019, 09:07:37 pm
content: Hi,I need an LCR meter, I got a tiny budget (30-60eur).I am expecting to measure inductance between:150µH to 25mH (seehttps://www.eevblog.com/forum/repair/needs-some-pieces-of-advice-on-how-to-diagnose-an-electric-fence/50/)I will probably get somewhere around .1mH to 30mH.So after searching I found 2 main contender for my use:uni-t 603DM4070I already got some uni-t clamp meter, It work just fine my use (tractors repairs).Do you guys have thoughst, I can't make up my mind. Because I like to go with the uni-t but I don't know if I actually need to get the 200µH range with a DM4070.Thanks.EDIT: I watched again this YT videoIt seems to be just fine in the 2mH and below (since it is a 2k points) (for 150µH). It seems I somehow missed it.Some people are talking about the frequency test of the device, it is adviced by some to get a 100kHz one, I can't get the information for those two.EDIT2: I just watched this video:I am getting mixed feeling about it.
What connectors rated for 3-6 kilovolts? - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: September 10, 2019, 08:09:09 pm
content: Hi!What connectors rated for 3-6 kilovolts?

author: picburner
author_rank: Frequent Contributor
timestamp: September 10, 2019, 08:26:07 pm
content: The standard SHV connector is 5KV rated but there are versions for higher voltages.

author: Someone
author_rank: Super Contributor
timestamp: September 11, 2019, 03:46:39 am
content: Banana jacks!5kV is around where you stop using normal cable and end up with graded insulators, so the connector is often dominated by the choice of cable. SHV or various Lemo connectors are targeting coax type cables. For discrete wire its usually brute force with enormous connectors that have enough clearance and creepage for the specific application, many low cost options here used with replaceable bulbs.

author: 001
author_rank: Super Contributor
timestamp: September 18, 2019, 05:44:15 pm
content: What about this?Is it some silicone toys on a common banana connectors?
Do anybody ownsthis portable baterry operated power supply - Page 1
Forum section: electronics / testgear

author: ebclr
author_rank: Super Contributor
timestamp: July 04, 2019, 08:30:05 pm
content: https://www.banggood.com/MINI-MDP-XP-Mini-30V5A-90W-2_4G-Wireless-Connection-Digital-Programmable-Power-System-with-2_8-inch-TFT-Screen-Monitor-Automatic-Matching-Control-6-Sub-modules-p-1526966.html?akmClientCountry=BR&utm_design=130&utm_source=emarsys&utm_medium=Mail_19prime08_30&utm_campaign=newsletteremarsys&utm_content=Gakki&sc_src=email_3758017&sc_eh=8b2bc17a6d103fa21&sc_llid=135888&sc_lid=153556246&sc_uid=rieh3kTfFS&cur_warehouse=CN

author: Kean
author_rank: Unknown
timestamp: July 04, 2019, 08:48:25 pm
content: I saw this earlier and I was wondering the same.Looks like they've re-purposed some kind of media player case for it.

author: thm_w
author_rank: Super Contributor
timestamp: July 04, 2019, 08:54:49 pm
content: Quote from: Kean on July 04, 2019, 08:48:25 pmHas to be the only financial way it would make sense, the product is incredibly niche. How many people are screwing around with measuring/testing their quadcopter motors in the field?If it were cheaper, it might be a competitor to daves usupply. They could probably get away with just the small OLED screen for showing voltage/current/power.The LED lit banana jacks are a nice touch.

author: MiniWare
author_rank: Contributor
timestamp: August 22, 2019, 07:55:33 am
content: Here have a review of MDP-XP power supply

author: electrode
author_rank: Regular Contributor
timestamp: August 22, 2019, 09:24:13 am
content: Eesh, $300(AU) for a Chinese power supply. I was expecting $50 when I clicked the link. No way of knowing the quality of the batteries or anything else inside it.I'll wait for the hopefully sub-$500 DaveSupply instead.

author: 001
author_rank: Super Contributor
timestamp: August 22, 2019, 11:47:10 am
content: You can power china dc-dc converter with ordinary powerbank for about $50I guess hum is not terrible

author: electrode
author_rank: Regular Contributor
timestamp: August 22, 2019, 09:17:26 pm
content: That's what I was thinking. Buck-boost with like 3 18650s in series (or parallel, depending on how the balancing v.s. efficiency calculations work out).

author: SteveyG
author_rank: Unknown
timestamp: September 12, 2019, 07:05:09 pm
content: Quote from: electrode on August 22, 2019, 09:17:26 pmIt's not battery operated. It needs an external power supply or PC.I just got sent one today to review, but it's honestly quite an odd product.
Fluke 8060A 300v vs. 1000v multimeters? - Page 1
Forum section: electronics / testgear

author: Axtman
author_rank: Regular Contributor
timestamp: September 12, 2019, 10:13:34 pm
content: How do I tell if my Fluke 8060A multimeter is the 300 volt or 1000 volt version?

author: Fungus
author_rank: Super Contributor
timestamp: September 12, 2019, 10:45:16 pm
content: Quote from: Axtman on September 12, 2019, 10:13:34 pmI think they're both the same, just different labels after people pointed out they weren't safe for 1000V on all possible ranges.(...was it 1000V or 750? My memory says 750V)

author: 4thDoctorWhoFan
author_rank: Regular Contributor
timestamp: September 13, 2019, 10:52:28 am
content: I believe the 300V meters would be the newest of the 8060A's and would have a AC RMS daughter board instead of the single chip RMS converter.If you have one of the older models, I would definitely replace all the electrolytics. I had three older models and in all three, the caps were leaking. The one "newer" model did not have leaking caps.
Is it possible to replase cathode voltmeter with handheld DMM? - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: September 13, 2019, 01:33:09 pm
content: HiThe manuals for old equipment say that when setting up, you need to use a cathode voltmeter.Is this relevant in 2019? Can I use common DMM?

author: TimFox
author_rank: Super Contributor
timestamp: September 13, 2019, 01:50:54 pm
content: Years ago, there were two common analog voltmeters used to troubleshooting equipment:1. Passive VOM, such as Simpson 260 in US, that had "20,000 ohms per volt" resistance, due to 50 uA meter.2. "VTVM", such as RCA "Voltohmyst", with 11 megohm input resistance, where 1 megohm was located in the probe before the cable to the meter box.Schematic diagrams often specified which type of meter was used to measure the typical voltages shown on the drawing.Note that the "VTVM" was better than modern DMMs for measuring test points where there was an AC component, since the resistor in the probe isolated the cable capacitance from the circuit. For example, when measuring the voltage at a cathode with an un-bypassed cathode resistor (for local feedback), the extra capacitance of the meter cable can possibly start oscillation, which will make a large shift in the DC voltage. If that be your problem with a DMM, a simple probe extension with a 1 megohm resistor may be needed, with an obvious math correction to the voltage reading.

author: Specmaster
author_rank: Super Contributor
timestamp: September 13, 2019, 02:00:08 pm
content: Almost certainly you can, cathode meter offers a input impedence of around 12Meg, much the same as a DMM and generally schematics specified that all voltages are taken with either a meter of 20,000 opv meter (VOM) or a cathode meter which will provide a far greater accuracy and will not load down the DUT.Sent from my POT-LX1 using Tapatalk

author: 001
author_rank: Super Contributor
timestamp: September 13, 2019, 02:04:16 pm
content: Quote from: Specmaster on September 13, 2019, 02:00:08 pmSorryBut what about input CURRENT?

author: Kleinstein
author_rank: Super Contributor
timestamp: September 13, 2019, 04:37:11 pm
content: The input current is essentially measured voltage divided by input resistance. So the 10 MOhms meter would dray some 20% higher current than a 12 M meter.The point to check may be the voltage range. Modern DMMs are usually limited to some 500-1000 V. For higher voltage it usually needs a separate high voltage probe, that may very well be 100 M or similar, but could also cost more than a handheld DMM.
Use JDS-6600 for filter alignment - Page 1
Forum section: electronics / testgear

author: Bart1965
author_rank: Newbie
timestamp: September 09, 2019, 08:49:15 am
content: My first post on this forum.I recently bought a JDS-6600 wave generator (the 60 MHz edition).I want to use it as a wobbulator to align IF filters. Does anyone know if there is a way to sync my oscilloscope (an ancient Philips PM3212) with the sweep period? I can't find any information on such an application of the JDS. It would be also great if the 0.1 second sweep period limit could be lowered to say 20 ms.

author: Andreas
author_rank: Super Contributor
timestamp: September 10, 2019, 09:23:27 pm
content: Have not tested it but I would try the following:(assuming that the frequency spread is small around a center frequency).CH1 FM-modulated from CH2CH2 with 50Hz = 20 ms triangle wave form.CH1 = Y-Axis on scopeCH2 = X-Axis on scopewith best regardsAndreas

author: Bart1965
author_rank: Newbie
timestamp: September 11, 2019, 10:32:01 am
content: I will try that. I am not sure though if JDS-6600 supports FM. Actually I assumed it didn't. The bandwidth is indeed small, a few 100 kHz around a center frequency at 10.7 MHz.

author: Andreas
author_rank: Super Contributor
timestamp: September 11, 2019, 07:34:10 pm
content: Hello,works at least with my FT6800 signal generator as you can see on a FFT with peak-holdwith best regardsAndreas
Datron 4708 op manual page request - Page 1
Forum section: electronics / testgear

author: volvo_nut_v70
author_rank: Regular Contributor
timestamp: September 11, 2019, 07:16:44 pm
content: Hello;All the copies I have come up with have an error in the scanning of pg 4-6 (see attachment). Does any one have an original paper copy that they could scan pg 4-6 and upload it or attach in a reply?Thanks!