hybridfree/eevblog-posts huggingface dataset:
Building a cheap DIY Oscilloscope - DSO150 - Page 1
Forum section: electronics / testgear

author: jcrubin
author_rank: Frequent Contributor
timestamp: October 28, 2019, 12:24:32 pm
content: Jason dropped off an oscilloscope kit from Skycraft in Orlando. He had found what appears to be a DSO150 kit, which sadly he picked up for a disgustingly high price of 50$ unassembled as I found it on Banggood assembled for 16$. The research for this, having been done later, and not worth time gas and tolls, I decided to just build it and give him the bad news in this video.Lets just build it.I follow along with the instruction and I note that the surface mount resistors and capacitors and IC's are not pre-soldered, in contrast to the instructions. Just the bigger components need be added.The adjustments for the capacitance of the probe is not accessible if the unit is assembled which makes calibration klunky.Does it work. Well, yes. For a portable device needing 9 volts with no battery, its not very portable, more of a gimmick. The Navigation is mediocre, but again to be fair, its a 16$ toy from Banggood, 60$ is the un-believeable markup from Skycraft, so for 16$ it does the job.

author: Gyro
author_rank: Super Contributor
timestamp: October 28, 2019, 12:59:41 pm
content: I keep one around for really basic portable stuff (well it was on offer). Having an external battery supply is a pain, but luckily these is sufficient space to add an internal Lipo celll and associated bits with a little ingenuity...https://jyetech.com/forum/viewtopic.php?f=19&t=1153

author: Jan Audio
author_rank: Frequent Contributor
timestamp: October 28, 2019, 02:12:56 pm
content: Where is the fun ?
Restoring my old HP8594E? - Page 1
Forum section: electronics / testgear

author: Miti
author_rank: Super Contributor
timestamp: October 24, 2019, 01:10:39 am
content: My fingers tingle again. After the successful complete recaping and upgrading to FRAM of my Tek 2445B, I feel that it is time for my HP8594E SA to get a rejuvenating treatment.However, I don't want to make things worse. The instrument works, but the screen gets a bit fuzzy with brightness, a clear sign of an old CRT.The question is, should I try rejuvenating the CRT, and with that occasion, replacing the caps in the display module?Also, should I replace those Rifa caps, and the electrolytics, in the power supply, before they do their firework number?What do you guys think? Should I jinx it or should I not?Thanks,Miti
Camera and for smd inspection/rework - Page 1
Forum section: electronics / testgear

author: IAmBack
author_rank: Regular Contributor
timestamp: October 23, 2019, 10:18:57 am
content: I'm about to make "microscope" for smd work.I am looking for c-mount camera and lens on ebay.I expect to pay less than $100 for camera. I want it to have HDMI output and (at least) full-hd resolution. There are some "14mp" and "16mp" cameras on ebay (some with panasonic, some with sony sensor). Can someone share experiences with those units?Also, I'm planning to buy "180X 0.5X-4.5X Zoom" lens (as by description). Is it good choice?Regards.Martin

author: tautech
author_rank: Super Contributor
timestamp: October 23, 2019, 11:46:08 pm
content: Defpom uses his one quite a lot:

author: EE-digger
author_rank: Frequent Contributor
timestamp: October 24, 2019, 12:16:37 am
content: If you want to document a problem on a PCB or an assembly, a microscope with camera is good.But for inspection and especially for rework, you will be much happier if you find a stereo microscope. I don't know what's available in PL but old Bausch and Lomb Stereozoom microscopes were in abundance at one time and are pretty cheap today. Or you may find one of the Russian stereo scope, which used to be around $400 when new, with accessories. The optics were not Leica but were fine for general use.I do a lot of SMT work and have also done a lot of work with video cameras and microscopes over the years. WIthout the 3D stereo view, the lack of depth perception makes it very difficult to solder, etc. For instance, when you are directly above a component with your soldering iron or tweezers, with 2D you can't tell if you are on the part or 3mm above it.Also, with many stereo microscopes, a 0.5x lens is a good accessory to reduce the magnification AND double the working distance.For SMT sizes of 1206 down to 0402 (and even 0201), magnification below 30x is generally good.A microscope with good camera and display looks great but is not very useful for small work. Sorry for not answering your question but hope this helps with your solution.
Tektronix TL721 power supply - Page 1
Forum section: electronics / testgear

author: velik_kazakov
author_rank: Regular Contributor
timestamp: October 18, 2019, 07:42:12 am
content: I get my new toy before 2 days - TLA721 main frame.Yesterday I install new hdd and install WinXp with TLA V.5.1 (wait for TLA7AA4 plugin to clear the customs here in Bulgaria and to install it for testing).The pc board lose the bios settings every time and I open the controller to exchange the battery. Find that the battery holder is desoldered - fix it and reassemble all.I plug the main power cord and something explode inside. I dissasemply the power supply and find a fried NTC inside it. Measure it - 29 Ohms but want to exhange it befor to close the power supply and to test it again. I try to find some schematic for this power supply, but I can't.Want to ask if someone have the same problems with this unit and what NTC is the right. Maybe it is not 29ohms because it is bad now.There I find some Rifa Y caps that will exchange all too befor to use it.Thanks in advance and sorry for my bad English.EDIT: All done - it is 15ohm / 4A NTC. Work fine now.

author: nctnico
author_rank: Super Contributor
timestamp: October 19, 2019, 12:14:33 am
content: What if you unsolder the NTC? Perhaps the value is printed on the other side.

author: velik_kazakov
author_rank: Regular Contributor
timestamp: October 19, 2019, 06:52:30 am
content: I do it. Have some glue on it and I can't read anything, but try to remove very carefully the glue and find it - 15SP016.

author: nctnico
author_rank: Super Contributor
timestamp: October 19, 2019, 10:31:05 am
content: A quick google shows this datasheet:https://datasheet.ciiva.com/11822/0900766b8124349f-11822067.pdf

author: velik_kazakov
author_rank: Regular Contributor
timestamp: October 24, 2019, 08:28:52 am
content: Quote from: nctnico on October 19, 2019, 10:31:05 amThanks, all done. It work now.
USB Oscilloscope around 100$ - Page 1
Forum section: electronics / testgear

author: Prithul0218
author_rank: Contributor
timestamp: October 22, 2019, 11:29:01 pm
content: HelloI am looking for an USB oscilloscope priced around 100$, since I can’t afford a bench one and I don’t want to buy a second hand oscilloscope either.Up to 120$ is okay.So please suggest a decent USB oscilloscope and thank you.

author: don.r
author_rank: Frequent Contributor
timestamp: October 22, 2019, 11:41:14 pm
content: Bandwidth? Hantek 6022BE is the go to for cheap USB.

author: Gyro
author_rank: Super Contributor
timestamp: October 23, 2019, 08:38:21 am
content: The Owon VDS1022I has much better performance than the Hantek and is galvanically isolated from the PC...https://www.eevblog.com/forum/testgear/owon-vds1022i-quick-teardown-(versus-the-hantek-6022be)/

author: MarkF
author_rank: Super Contributor
timestamp: October 23, 2019, 05:51:42 pm
content: PicoScope:https://www.picotech.com/oscilloscope/2000/picoscope-2000-overview
New budget RD-6006 PSU product - Page 1
Forum section: electronics / testgear

author: PKTKS
author_rank: Super Contributor
timestamp: October 23, 2019, 02:27:17 pm
content: RD strikes again with a larger form factor...https://www.aliexpress.com/item/4000282551930.html

author: PKTKS
author_rank: Super Contributor
timestamp: October 23, 2019, 02:48:07 pm
content: just realized that these are "old" news...https://www.eevblog.com/forum/testgear/ruideng-riden-rd6006-dc-power-supply/nevertheless... we do "UP" on all of them.apart from price class - the products add value for the money...
Looking for Fluke 8840A Option 09 Board - Page 1
Forum section: electronics / testgear

author: worsthorse
author_rank: Super Contributor
timestamp: October 23, 2019, 10:56:39 pm
content: I recently found two Fluke 8840As at a hamfest. I am putting them together to make one working DMM. Neither, however has the RMS VAC measurement board, akaOption 09.If you have this board (Fluke PN is 728899) or a scrap 8840A/AF with this board installed that you are willing to sell, please PM or send me an email. Thanks!
Does anyone have a Tektronix RSA6106A software/driver set? - Page 1
Forum section: electronics / testgear

author: fuji412
author_rank: Newbie
timestamp: October 19, 2019, 01:25:26 pm
content: Hi!I'm looking for RSA6106A (or RSA6000 series) device drivers and software, HDD images, or deployment packages.Or can someone show me the device manager of the actual RSA machine?I got a junk Tektronix RSA6106A. However, there was no HDD and I installed Windows XP myself.I downloaded the RSA software from the Tek website, but it doesn't contain the drivers I need.I extracted the driver from DPO7000 and installed it, it fits, but maybe needs a customized driver for RSA.Thank you!

author: rvalente
author_rank: Frequent Contributor
timestamp: October 20, 2019, 07:57:07 pm
content: Since its not a commom piece of equipment, have you tried to reach Tek support?

author: fuji412
author_rank: Newbie
timestamp: October 21, 2019, 01:50:15 pm
content: I contacted tektronix support, but the RSA6105A has already expired support service and I could not purchase maintenance parts (media or HDD)...
100Mhz handheld DSO with IPS LCD for $74? - Page 1
Forum section: electronics / testgear

author: 001
author_rank: Super Contributor
timestamp: October 20, 2019, 07:39:13 pm
content: Any Ideas?https://www.ebay.com/itm/Handheld-Digital-Oscilloscope-100MHz-500MS-s-DSO-2-4-inch-IPS-LCD-Display/233362295919?hash=item36557a0c6f:g:6KUAAOSwAxpdmuJL

author: Kosmic
author_rank: Super Contributor
timestamp: October 20, 2019, 07:42:19 pm
content: https://www.eevblog.com/forum/testgear/daniu-ads5012h-100mhz-500-mss-portable-scope-for-$80-usd/

author: ataradov
author_rank: Super Contributor
timestamp: October 20, 2019, 07:48:22 pm
content: Andhttps://www.eevblog.com/forum/projects/reverse-engineering-fnirsi-5012h/Currently stalled due to LAX customs talking more than 10 days to get my LCSC order through.

author: ataradov
author_rank: Super Contributor
timestamp: October 20, 2019, 07:49:19 pm
content: IPS display got replaced by TFT and 5000mAh battery got replaced by 3000mAh a long time ago, but less honest sellers do not bother to update the description.

author: 001
author_rank: Super Contributor
timestamp: October 20, 2019, 07:51:53 pm
content: Thanx a lotI`m misled with no name unit
Flir CM55 Teardown - Page 1
Forum section: electronics / testgear

author: threephase
author_rank: Regular Contributor
timestamp: October 20, 2019, 07:22:19 pm
content: I was playing around with a home-brew current amplifier and coils with a CM55 current probe from Flir and couldn't stop myself from taking a little peak inside.This is a 3000A Rogowski style current probe, with bluetooth wireless comms and inrush monitoring function.Total of 7 self tapping screws needed to be removed to get into it, three inside the battery compartment and two hidden behind one of the labels. Anyone would think they didn't want you to look inside it....Few basic pictures to get you started with, closeups of the board to follow in next post.

author: threephase
author_rank: Regular Contributor
timestamp: October 20, 2019, 07:25:36 pm
content: Few more pictures of the PCB inside the Flir CM55

author: threephase
author_rank: Regular Contributor
timestamp: October 20, 2019, 07:27:26 pm
content: Photos inside the case and the Rogowski coil

author: threephase
author_rank: Regular Contributor
timestamp: October 20, 2019, 07:28:18 pm
content: Final Higher resolution of PCB
Suggestion of Ultrasonic cleaner for general PCB cleaning and flux removal? - Page 1
Forum section: electronics / testgear

author: Fusion916
author_rank: Regular Contributor
timestamp: October 16, 2019, 11:06:02 pm
content: What do you guys suggest for an ultrasonic cleaner than can be used for flux removal? Also what flux removal solution do you suggest?

author: DaJMasta
author_rank: Super Contributor
timestamp: October 16, 2019, 11:10:38 pm
content: There have been a few threads on it, but I think you can probably get some good info as replies too.In my limited experience, there are the expensive ultrasonic cleaners that most people can recommend, and then there are the various cheap brands of varying quality. I ended up going with a cheapy with certain restrictions: all stainless steel, variable frequency, with preheater, and it was around $100 for something that can accommodate small to medium (almost video card size) boards, and I've been fairly happy - though no gasket on the lid or damping on the basket makes it quite noisy in operation until dampened.... even then I like to run it in another room with the door closed.As for cleaners, I use alconox. Comes dry and dissolves quickly, seems to be generally regarded as safe, easy to use, and good for a lot of cleaning types. The kind of flux you're cleaning off matters, and there are cleaners specifically for flux too. Some people will recommend isoproyl alcohol, and others will tell you that heating and agitating IPA in a small area is a recipe for starting a fire - I have no experience using it, I'll stick to regular detergents and water.

author: james_s
author_rank: Super Contributor
timestamp: October 17, 2019, 12:25:37 am
content: I use an old Branson that originally came from a dental clinic. It was originally expensive but I didn't pay much for it. Might be worth checking the used market, these things are typically pretty reliable.

author: MarkF
author_rank: Super Contributor
timestamp: October 17, 2019, 12:29:17 am
content: F.Y.I.

author: nukie
author_rank: Frequent Contributor
timestamp: October 21, 2019, 02:28:17 am
content: Gold Standard -https://www.elmaultrasonic.com/DIY/Home gamer -https://www.aliexpress.com/af/pcb-ultrasonic-cleaner.htmlYou want a waterbased flux cleaning detergent. Avoid solvents or flammable products in an ultrasonic cleaner.
"High-Precision-4-Wire-Milliohm-Meter-Microohm-Meter" - Page 1
Forum section: electronics / testgear

author: Electro Fan
author_rank: Super Contributor
timestamp: October 05, 2019, 08:54:27 pm
content: Anyone have any experience - or thoughts - regarding this?https://www.ebay.com/itm/High-Precision-4-Wire-Milliohm-Meter-Microohm-Meter-With-Test-Clip-dl45/163772918520?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D60256%26meid%3D6378112b91464d85a67fdc2a1d984540%26pid%3D100005%26rk%3D2%26rkt%3D12%26mehot%3Dsb%26sd%3D182822385304%26itm%3D163772918520%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c100005.m1851

author: Martin72
author_rank: Super Contributor
timestamp: October 05, 2019, 09:03:20 pm
content: I coudn´t get it, the meaning of "high precision" and tolerances up to 10% depending to the range…..

author: trobbins
author_rank: Frequent Contributor
timestamp: October 06, 2019, 01:38:03 am
content: How can a meter have a 0.1mohm resolution but only dispay 1 mohm resolution when measuring a 47 mohm resistor?

author: nukie
author_rank: Frequent Contributor
timestamp: October 20, 2019, 09:16:48 am
content: I suggest the Deree DE-5000. It's got 1mOhm resolution but better than the no brand 0.1mOhm eBay deal.

author: Shock
author_rank: Super Contributor
timestamp: October 20, 2019, 06:57:47 pm
content: I agree, here is an oldie but goodie showing the DE-5000 and measurement reproducibility. ESR meters also make cheap milliohm meters but the DE-5000 is way more versatile for that extra money. Just not the best idea using it for in circuit component testing that is all.
Keithley 602 scale - Page 1
Forum section: electronics / testgear

author: justanothername
author_rank: Regular Contributor
timestamp: October 04, 2019, 07:59:10 pm
content: Hello Forums!Today I ruined my Keithley 602 scale by accident.Is anyone able to provide me a scan of that scale or, better, a replacement?

author: justanothername
author_rank: Regular Contributor
timestamp: October 06, 2019, 04:22:49 pm
content: Hello.So I made a replacement scale for the 602. Propably it will fit to the 610 as well. Files attached. PDF and DXF for the laser.

author: justanothername
author_rank: Regular Contributor
timestamp: October 19, 2019, 09:13:51 pm
content: I may be talking to myself or no one but maybe someone will have the same problem as I had replacing the mercury cell inside this meter.My solution is aSaft LS14500sealed primary cell with 10 years shelf life and 2600mAh capacity, followed by aTPS709135ldo with 1µA Iq. Mounted on adapter pcb with some capacitors.There is some very small amount of noise visible in the 0.001 range multiplier setting, but totally acceptable and now this meter is finally fully restored.

author: don.r
author_rank: Frequent Contributor
timestamp: October 20, 2019, 03:13:43 am
content: Excellent work! It looks beautiful.
What is this connector? Anritsu 37347C - Page 1
Forum section: electronics / testgear

author: pratiken
author_rank: Contributor
timestamp: October 22, 2019, 11:32:35 pm
content: HiI'm using an 37347C and I'm wondering what this connector is? Ultimately, I'd like SMA M.The datasheet says it's Universal K (male) which I learned is 2.92mm and also the shares the same pin as SMA. However, I don't think it's a good idea to screw an SMA F in there, is it? Is there a bulkhead adapter that would protect the instrument's connector and allow me to connect an SMA M cable to it safely?Thank you for the advice!!

author: EE-digger
author_rank: Frequent Contributor
timestamp: October 23, 2019, 12:37:08 am
content: From Radiall (a high quality connector mfgr):SMA 2.9 (K)Sub miniature screw-on connector, operating in the range DC-40 GHz50 ohms / part series R127SMA 2.9 also called "K" or "2.92 mm" connector was developped in the 1980's and is standardized per IEC 61169-35.Intermateable with SMA and SMA3.5, SMA 2.9 is used for test and measurement and for high frequency microwave modules. The range includes some SMA 2.9 connectors specified up to 46 GHz.I would not bring an SMA near it if it's in good shape.

author: pratiken
author_rank: Contributor
timestamp: October 23, 2019, 06:37:35 am
content: Thanks EE-Digger!The device I'm testing is SMA F, so I'm going to use cables that are SMA M to SMA MIf I understand this right, I need a 2.92mm to SMA converter such as this one?https://www.digikey.com/product-detail/en/amphenol-sv-microwave/SF1115-6005/SF1115-6005-ND/6201679

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: October 23, 2019, 10:47:38 am
content: This is a common connector type on VNAs which are ruggedized connectors. They use the female connectors, and if you get the fancy phase-stable VNA cables from the manufacturer, you will often find they first thread on the inside and then have a second connection to the outer thread for increased strength.You really should not connect an SMA to a VNA 2.92 mm. It can be okay if you have high-quality SMA connectors but even then should be avoided. You could use a connector save for this, such as the one you suggested.
Siglent SDS1202DL Firmware upgrade - Page 1
Forum section: electronics / testgear

author: evansg
author_rank: Contributor
timestamp: October 19, 2019, 04:12:57 pm
content: It seems that I uploaded a wrong firmware to my old Siglent SDS1202DL Oscilloscope and now it does not work properly.I used the SDS1000CFL 2CH Firmware - 5.08.02.38 (Release Date 03.10.15 ) and unfortunately it accepted the wrong firmware.It boots and all menus/buttons works except the most important thing.. to measure. (I can see a sinusoidal graph after boot in both channel when nothing is present connected to the device)Anybody has the correct firmware for the SDS1202DL?Thanks,Evans

author: tv84
author_rank: Super Contributor
timestamp: October 19, 2019, 07:02:56 pm
content: Decompress zip and 7z.

author: evansg
author_rank: Contributor
timestamp: October 19, 2019, 09:06:02 pm
content: Thanks man, back to normalAppreciate your help!
HP16500C with HP16517A & HP16518A cards - Page 1
Forum section: electronics / testgear

author: vincei
author_rank: Contributor
timestamp: October 16, 2019, 08:30:59 pm
content: I just got a job lot of HP16517A & HP16518A cards with jumpers to gang the cards together. I installed the cards into a 16501A mainframe and connected it to a 16500C that has other cards in it.All 5 slots in the 16501A with the 18A/17A cards are showing "unrecognized card". I can't believe all these cards are dead - highly unlikely - so what do I need to do to get the device to recognize the new cards? I can post pictures if required.Thanks!Vince

author: MadTux
author_rank: Frequent Contributor
timestamp: October 17, 2019, 12:03:06 am
content: See if 16500C mainframe has the "driver" files installed. Should be a file with 16517 or 16518 in it.Should be on a couple of floppies that you could download fromHPKeysight website.Without that file, the card isn't recognized.

author: vincei
author_rank: Contributor
timestamp: October 18, 2019, 08:52:41 pm
content: Hi, Thanks for the response. Apologies for the late reply - I wanted to make sure that I had all bases covered.As it turns out I didn't really have to do anything in software. It occurred to me that the mainframe and the cards that I purchased are very old and were giving strange and random device id's hence being unrecognized. I sprayed all the connectors on all five cards and the expander frame edge connectors with M&G chemicals contact cleaner and re-seated all the boards. And, boom, happy Vince.In the multi-day search for what might be the issue I also tracked down the last firmware version release by HP for the 16500C - it was extremely difficult to find! Over the weekend I'll backup the hard-disk and take a shot at installing this later version of the software.https://www.keysight.com/main/editorial.jspx?cc=US&lc=eng&ckey=1000004086:epsg:faq&nid=-536902551.536880500&id=1000004086:epsg:faqThanks again for the assistance!-Vince
MDA3V dist. amp impedance mismatch - Page 1
Forum section: electronics / testgear

author: tkamiya
author_rank: Super Contributor
timestamp: October 17, 2019, 09:09:45 pm
content: I am using Extron MDA 3V distribution amplifier (1 input, 3 output, all 75 ohm) for 10MHz distribution. Cables are all RG58 of some kind. I think 75ohm/50ohm mismatch is not a big deal as VSWR is only 1.5, AND equipment 10MHz input is not always 50 ohms. Am I correct in my assumption?I did locate the output/input resister in MDA 3V but I'm kind of lazy to change them.
SDS1202X-E calibration  - Page 1
Forum section: electronics / testgear

author: CDaniel
author_rank: Frequent Contributor
timestamp: October 06, 2019, 03:42:54 pm
content: It is possible somehow to calibrate this scope to be spot-on ?Mine is showing someting like 3,75V rms when it should be 3,5V rms at any frequency ( of course the rest of measurement , amplitude and so on are affected too ) . The error is the about the same at any input voltage and attenuation .It is not the probe , it's the same with a simple cable BNC to BNC . The signal is measured with calibrated instruments , so there is no external error .This was the same when it was brand new .Self calibration was done of course numerous times , the firmware is updated to the latest version .

author: HendriXML
author_rank: Super Contributor
timestamp: October 06, 2019, 09:35:25 pm
content: Do you experience the same inaccuracies with DC signals?(Have you checked that no voltage is lost over the ground lead from the bnc cable? I used to have a usb signal generator that drew current and thus dropped voltage)I think I saw a calibration manual for this scope serie though. But calibrating requires the right equipment.

author: HendriXML
author_rank: Super Contributor
timestamp: October 06, 2019, 10:50:07 pm
content: Service manual:http://siglentna.com/wp-content/uploads/dlm_uploads/2017/10/SDS1000Xplus_ServiceManual_SM0101X-E01A.pdf

author: Rerouter
author_rank: Super Contributor
timestamp: October 06, 2019, 11:49:14 pm
content: Another thing, Are you on a fine channel gain or a course one? if its like the 4 channel model, there was a few fine steps that until the firmware was updated where incorrect.

author: LvdK
author_rank: Newbie
timestamp: October 17, 2019, 07:16:04 pm
content: Dit you see EEVblog #1223 and #1226 ? Very instructive, it helped me.
Vintage Electronics: Hungarian Function Generator! - Page 1
Forum section: electronics / testgear

author: moboch
author_rank: Contributor
timestamp: October 17, 2019, 05:52:58 pm
content: Bought this old function Generator from eBay for 40€ Delivered(!). It works without any problems. Now comes the good part: The insides.Photos of the main PCB is attached. The best thing about the PCB is that the "functional blocks" are labeled on the silkscreen! The seller even provided me with schematics, a (hand drawn!) block diagram and a PCB layout of the mainboard. Photos of everything i mentioned are attached. I don´t know from when this is so maybe you know some more.Link to more pictures because I could not upload them all here:https://workupload.com/archive/stNTPrw

author: Yansi
author_rank: Super Contributor
timestamp: October 17, 2019, 06:10:51 pm
content: That's indeed a thing of beauty.
Fluke 175 'modification' - Page 1
Forum section: electronics / testgear

author: AudioFile
author_rank: Contributor
timestamp: October 16, 2019, 01:40:16 pm
content: I recently acquired a Fluke 175 in fair condition. After servicing it works pretty much as per specification, but I see that two tracks have been cut on the pcb. These are on tracks marked with the diode symbol (see pics).Does anyone know why such a 'mod' may have been made? I'm minded to reconnect the tracks but thought I'd check with the experts first.The only deviation from spec is that the continuity buzzer works at 50 Ohm, whereas the spec says it should sound at <25 Ohm and turn off at >250 Ohm. I wonder if this is why the tracks were cut? Seems a drastic thing to do if so.Help appreciated.AudioFile

author: brabus
author_rank: Frequent Contributor
timestamp: October 16, 2019, 02:43:43 pm
content: IMvHO the "mod" only affects the backlight. The tracks seem to go to the LCD backlight LEDs, but the LEDs seem never to be mounted on those shiny pads.The continuity buzzer function seems fine to me as well.I wonder why someone would cut traces, without them having any effect on the function. EMC maybe?

author: Paul Moir
author_rank: Frequent Contributor
timestamp: October 16, 2019, 02:46:59 pm
content: Weird: It looks like they've cut the traces to the backlight LEDs for the 177&179. The LEDs go in those diode symbol footprints. If you install the LEDs, drill a hole in your case and install a rubber button set from the 177/179 they will work. It's almost as if someone wanted to inhibit someone from modding it by smashing up the tracks.I'm sure my 175 doesn't look like this.

author: AudioFile
author_rank: Contributor
timestamp: October 16, 2019, 03:45:40 pm
content: Guys, thanks for the quick and helpful replies. Yes I can see now those tracks are for the LEDs which were fitted on the 177/179 only. If it weren't for the ugly way they have been cut, I'd suspect Fluke for protecting sales of the 177. I think I'll leave it alone for now.

author: retiredcaps
author_rank: Super Contributor
timestamp: October 17, 2019, 03:47:10 am
content: Fluke 175 modded by modemhead.https://www.eevblog.com/forum/testgear/fluke-175-and-179-side-by-side-backlight-hack-on-fluke-175/
BK Precision 2831E (5491B) ZERO CAL - Page 1
Forum section: electronics / testgear

author: Ringmodulator
author_rank: Regular Contributor
timestamp: March 21, 2019, 07:46:21 am
content: Hi,in the system menu of the BK Precision 2831E, there is an entry for "ZERO CAL".To perform this, the entry of a numeric key is required.Through trial and error, I found, that the key is 6666.The volt in socket has to be shorted to the ground socket.After confirmation with ENTER, the selfcal runs automatically.I have tested this with the 2831E and this will most likely also work with the sister model 5491B.Chris

author: xxx2fan
author_rank: Contributor
timestamp: October 13, 2019, 01:17:00 pm
content: Thank you very much.I will try this zero cal this afternoon and let everyone know how I made out. My AC volts is reading way high right now.B&K2831Exxx2fan

author: xxx2fan
author_rank: Contributor
timestamp: October 13, 2019, 02:24:45 pm
content: Could you please post the key strokes to get to the Zero Cal and exactly the step by step to do the zero cal I can get to the C:SYS MEU but can't get to the zero cal and step through the procedure to do itThanks for your help

author: Ringmodulator
author_rank: Regular Contributor
timestamp: October 14, 2019, 07:58:51 pm
content: Hi,it is in the SYSTEM MENU, the last entry.Check the manual. In the PDF it is on page 11.Just google 2831Eand5491B_manual.pdfIn the Zero Cal menu hit enter.It is very much selfexplaining.

author: xxx2fan
author_rank: Contributor
timestamp: October 15, 2019, 12:50:27 am
content: Thanks for the info

author: xxx2fan
author_rank: Contributor
timestamp: October 16, 2019, 10:46:32 pm
content: My B&K 2831E is leaving tomorrow to B&K repair. The AC voltage at line voltage is about 9 volts high manual and auto. I did some research and the Zero Cal zeros out the leads for OHMS and has nothing to do with the rest.Thanks for the info you posted. You can get the cal software but if it goes south you have a paper weight.Out of warranty repair/cal without paperwork for the cal is 170 and 30 dollars shipping no good on my bench the way it is. Love the display on this meter so.......... we'll get it to specs.Thanks for the information from everyone
Multimeter with probe holders on the sides vs back - any advantage? - Page 1
Forum section: electronics / testgear

author: sleemanj
author_rank: Super Contributor
timestamp: October 15, 2019, 09:13:33 pm
content: So I was looking around Aliexpress meters in the $10-20 range, and came across a couple of (new?) offerings from BSIDE (who previously have been a Mastech rebadger), probably also sold by others but I haven't actually seen any, theADM62 (2000 cnt), ADM66 (6000 cnt)andADMS6 ("smart", or perhaps "silly")These all seem to have the same case design and what is most striking is the probe holders being on the sides rather than on the back as is "traditional". Aesthetically I think this looks really dorky, like big flappy ears, but I'm wondering if there is some advantage to having them on the side rather than the back, perhaps in the way maybe electricians or something might use them? I can't say I've actually had any reason to use a meter's probe holders for anything at all, but my meters seldom leave my bench.

author: tautech
author_rank: Super Contributor
timestamp: October 15, 2019, 09:23:59 pm
content: Rear ones are better and yes they are useful when you have nowhere to put your DMM other than to hold it.....unless you have 3 sets of hands.

author: threephase
author_rank: Regular Contributor
timestamp: October 16, 2019, 04:44:40 pm
content: I have used the probe holders when working inside panels. Allows me to hold the meter in one hand with the probe in its holder on the neutral or common and probe around with the other.For me there is no real difference in side or rear mounted holders. You might find on the odd occasion that the layout of the components in a panel favour one type or another for access, but most of the time I can cope.Kind regards.
OSSW/OSHW automated semiconductor analyzer - Page 1
Forum section: electronics / testgear

author: rhb
author_rank: Super Contributor
timestamp: October 15, 2019, 10:03:32 pm
content: I've been scratching an old itch for the last few days. I just went back and looked at a bunch of old curve tracer threads, but none was really as ambitious as what I have in mind.I've got a Peak DCA75 which is an excellent piece of kit, but I'd like something more comprehensive. The cheap LCR transistor testers such as the BSIDE ESR02 Pro and the nanoVNA are very powerful demonstrations of what can be done with clever design and modern parts. When I got involved with electronics, such things were simply outside the means of a hobbyist. I'm old now and can afford to buy a 30 year old piece of Tek or HP gear. But I think an OSSW/OSHW design would be more valuable for the same price if it can be reproduced cheaply enough.A general outline of what I have in mind is a device with 3 terminals. Connect a DUT, close the lid and it probes for the type as does the BSIDE or DCA75, but in addition, measures breakdown voltages to 1000 V and every other parameter which can be accurately measured without device specific test fixtures.At the conclusion it generates a PDF datasheet for the device. Eventually I'd like to be able to look up the part in a database and check that the measured values are within spec. But that's a long way off. First I just want to measure the DUT parameters with an OSSW/OSHW tester which could be sold on ebay for around $100 or less.At present I'm working on a low current digitally controlled 0-1000 V PSU that can be pulsed at low duty cycles for 50-500 microseconds at various voltages to determine breakdown voltages. I found that MOSFETS with ratings in the 1200-1500 V range are reasonably cheap, well under $1 in quantity. The cost goes up rather quickly above that.For the digital control of the HV supply I have in mind using PWM from an MCU to generate a variable voltage sine wave and feed that to a transformer. There's not a lot of current needed for the breakdown tests, in fact limiting is needed. But with a 1-2% duty cycle, just using a small capacitor should take care of that.At the moment my "transformer" is a 380 uH ferrite choke with a single turn through it for the 2nd winding. I've been testing it in step down mode because I don't want to damage anything. It's 1:100, so I'm going to put a 2 turn primary on it, add a rectifier bridge, capacitor and 1 Meg load resistor and start feeding low level sine waves to it using an AWG while checking operation with a scope and DMM.There are, of course, high current tests which are needed, but with Farad capacitors available that seems fairly tractable in pulsed operation at least up to 10 V or so.MCUs such as the STM32F429 provide 3x 2.4 MSa/s 12 bit ADCs. With those multiplexed to read the B, C & E currents and the voltages across the junctions, one should be able to get 200-300 measurements during a 300 us pulse as is commonly specified in datasheets.Reg
Function Signal Generator for circuit testing - Page 1
Forum section: electronics / testgear

author: Smash54
author_rank: Newbie
timestamp: October 15, 2019, 03:34:48 pm
content: Hello All.I'm working on building a Guitar Pedal and thinking of using one of these Onyehn XR2206 High Precision Function Signal Generator for signal tracing.https://www.amazon.com/dp/B078X9PVX3/ref=cm_sw_em_r_mt_dp_U_KjEPDbQBF4AFBWhat I'm thinking is to inject the signal into the audio path and monitor with my Scope. I had one of these a few years ago and it died I'm thinking I shorted it out don't think it has any protection built in. Is there any protection I could add to this, the circuit is 9 Volts.
tektronix tcpa300+tcp303 on fluke 190-204 - Page 1
Forum section: electronics / testgear

author: embun
author_rank: Newbie
timestamp: October 15, 2019, 12:17:14 am
content: Dear all..Long ago I bought a used tektronix tcpa300+tcp303 current probe for around USD500 but never really use it and left it in storage in my house in other city. Now, I bought a used fluke 190-204 and need current probe for some testing.Can I use tektronix tcpa300+tcp303 on fluke 190-204 and get a good reading ?My other concern is current probe sensitifity in fluke 190-204 in the range of 1, 10, 100, 400 mV/A, but the tcp303 is in the range of 5A/V and 50A/V.Does it mean 200mV/A and 20mV/A in fluke ?can I use 6dB attenuator to make it 100mV/A dan 10mV/A (I'am not really sure about this suggestion) and still got a good reading ? is there any better sollution?Please help, I cannot test it my self because now I live in appartement on different island, and it will be costly if I get it and not working after that.is a used fluke i310s a good alternative ?Sorry for my English and thanks for any thought.
HP 1660AS L.A./Scope - Page 1
Forum section: electronics / testgear

author: Andy53
author_rank: Newbie
timestamp: October 16, 2019, 05:23:47 pm
content: Hi, l'am new to this forum and have a question about HP 1660AS. (same scope inside as HP 16532A)When using the scope in repetitive mode, there is a very low screen refresh rate on the screen for the measuring signal (about 3 Hertz max. I guess).Is this normal due to FISO memory used or a fail function ?I think reading 8k RAM with lets say 50 Hz gives a DataStream from 400Khz, it must be not a great problem for a 25Mhz multitasking CPU, or am I wrong ?
Kunkin KP-184 Reviews? / Good , cheap load? - Page 1
Forum section: electronics / testgear

author: Noy
author_rank: Frequent Contributor
timestamp: September 20, 2019, 08:43:32 pm
content: Hi,i need a DC Load for switching power supply testing.Up to 50V or 10A is needed. With less than 100W.But i want test "load jumps" like embedded Linux system cpu/gpu load scaling. And for regulation loop testing.Does somebody know If the cheap kunkin KP-184 DC Load is good for this?I can get it for 160€ on eBay...

author: Noy
author_rank: Frequent Contributor
timestamp: September 21, 2019, 02:50:33 pm
content: Nobody knows something?

author: doktor pyta
author_rank: Frequent Contributor
timestamp: October 12, 2019, 09:01:48 pm
content: So I bought one and now I regret.I got a faulty instrument which I decided to repair... without spectacular success and I cannot return it. So beware.First issue: rotary encoder with insufficient debouncing. It was impossible to set value I wanted.Adding 2x10nF in parallel to existing approx 2x4.7nF located near encoder did help.Second and biggest issue: voltage readout hangs up in random moments and never goes back to normal operation.This is really killing bug during battery test. Battery cut-off voltage feature does not work due to this bug and discharges battery to almost 0V.My investigation showed that during hang up SPI (between uC and ADC) stops working (no SCLK).Hang up is rather not related to EMI.It is also interesting that I cannot measure any oscillation across uC crystal oscillator despite I'm using 1/10 probe.If someone could confirm this crystal observation I would be grateful.

author: doktor pyta
author_rank: Frequent Contributor
timestamp: October 14, 2019, 08:57:49 pm
content: To make things clear: if You get good unit, it is nice, small versatile and good value for the money.
Feeltech FY6800 with battery and more - Page 1
Forum section: electronics / testgear

author: Grubi
author_rank: Contributor
timestamp: September 20, 2018, 05:34:26 pm
content: Anyone with FY6800, FY6600 or similar, and patch/try to run those from battery?Removing the AC/DC power supply clean a lot of space and it will be great ifthis thingy can run on a battery. Don't know what Cyclone FPGA and output20V will need, though. Will measure on power connector tomorrow.Just received mine from ebay - dead on arrival, open the cover... someone forgot toplug power supply connector on... now it is fine.Last question - have someone try how external VCO, is it working?Want to modulate few Hz square signals with 50/100Hz or so,for driving some LCD shutter cells.Thanks in advance!

author: rvalente
author_rank: Frequent Contributor
timestamp: October 14, 2019, 11:43:11 am
content: I do not own one of them yet but, I believe the need 3 rails: +5, +12 and -12V. All can be made with off the shelf bricks or, you can design your own board with charger and etc...
MESTEK DM100C multimeter - Page 1
Forum section: electronics / testgear

author: floobydust
author_rank: Super Contributor
timestamp: October 13, 2019, 10:14:54 pm
content: Picked up DM100C for $25 with leads and thermocouple and find it disappointing - I give it a fail.Took it apart and there's a barnacle on the mA current shunt. Anyone else seen this? No need if you calibrate using EEPROM...It's an added 68R 0805 parallel to the R56//R18 mA current shunt, goal seems to be 4.99R100uA shunt is huge at 5k ohms, compared to 100R in AN8008.100mA shunt is 5R.600mA shunt 0.5R and the range is silly for a 10,000 count DMM. So 750mA reads as 00.75A on the next (10A) range.10A shunt 0.05R with 10 second time limit for currents over 5A, according to the manual. There is only a 99.99A range (no 9.999A) i.e. you will read 01.17A instead of 1.169A like AN8008.So some ranges are just oddball, and missing sig digits.Continuity resolution is only 1, there is no decimal point and the beeper is really slow.DCV autoranging goes down to 1V scale, no 100mV unless you rotate to manual range.The firmware is buggy and jack-detect expects you to turn the range knob, then connect jack in. If you are already in the right jack beforehand, it beeps, gotta pull it and put it back in. Now it's thankfully stopped working altogether except for the 10A jack, lol. There is no null/zero feature.Inside is the familiar Dreamtech DTM0660L. "Smart double-core" seems to be just a COB LCD display processor.The display is fast, overall the meter is just as fast as the AN8008 except for the beeper.Creepage and clearance have several violations so it's not a 1,000V Cat. III 61010 puppy.Current draw is about 26mA on 3V. LED backlight uses 3.3V boost converter. Reference is LM385-2.5V in SOT-23.I did not peek at the serial data out or diassemble the EEPROM.It's just a confused multimeter - has partial both auto and manual ranges.

author: 001
author_rank: Super Contributor
timestamp: October 14, 2019, 10:50:49 am
content: thanx a lot!it is wery strange to buid dtm0660 meter wrong way
Tek AM503 Schematics - Page 1
Forum section: electronics / testgear

author: tecman
author_rank: Frequent Contributor
timestamp: February 04, 2019, 05:33:48 pm
content: I have a Tek AM503B that needs some minor troubleshooting. I have only been able to find schematics for the AM503A on line. Does anyone have a copy of AM503B schematics ?If not, does anyone know if the AM503A schematics are similar to the B version ?Paul

author: r0d3z1
author_rank: Regular Contributor
timestamp: October 14, 2019, 09:31:49 am
content: Hello, I am also looking for the Am503B schematics, but it looks like that is hasn't be released. From what I have read, AM503A and B are similar in some parts but different in other.

author: jonpaul
author_rank: Super Contributor
timestamp: October 14, 2019, 08:15:32 pm
content: Bonjour à tousI have all three models AM503/A/BI believe that A and B have significant differences.I may have printed manuals or PDFs of either or both but I am traveling away from my lab for some time.Contact me via email if you can wait 1-2 monthsBon journéeJon
Anritsu/Wiltron 372xx schematics - Page 1
Forum section: electronics / testgear

author: Staffan321
author_rank: Regular Contributor
timestamp: October 13, 2019, 07:08:53 am
content: Hello,Anyone has schematics or any service information for the Wiltron 37xxx series of VNAs? I have a Wiltron 37247A network analyzer with a dead LO. My first guess is the YIG driver, most likely a supply voltage. Problem is that the power supply seems OK.Any documents or information apart from what I already found on Anritsu's website would be of great help! I have searched ko4bb.com, elektrontanya.com and contacted Artek manuals, but to no avail.Many thanks in advance!Regards,Staffan
HP8648 information request - Page 1
Forum section: electronics / testgear

author: tkamiya
author_rank: Super Contributor
timestamp: October 10, 2019, 06:12:49 pm
content: I have HP8644A and B, so I'm pretty familiar with these.I have been looking at HP8647 and HP8648 series but few things aren't clear. I wonder if someone who owns these can help me out.I found a pretty nice comparison here, which answered a lot of my questions already.http://www.libertytest.com/assetmanager/uploaded/pdf-201031-145924-hp_864x.pdfWhat it doesn't mention are:These models come with LCD and FD display. Yet, they don't appear as options. Did they start with one type and switch to the other?How are these models different from HP8644 series besides the obvious? (size and weight) These all come from the same time period. Are these good, better, best kind of difference? If so, where are these models positioned in HP's line up?Before anyone asks, I want these because of its size and weight. I always hurt myself trying to move what I have. So lighter is an advantage.

author: nfmax
author_rank: Super Contributor
timestamp: October 10, 2019, 06:30:26 pm
content: These instruments started out with LCD displays and were modified to use VFDs towards the end of the 'HP' era. I have an HP 8647A with LCD display, and an Agilent 8648D with VFD display.They are low cost, basic signal generators. The signal purity (phase noise, residual FM) is not very good, though the 8648 is significantly better, and they exhibit wideband noise on the output. They are best suited to 'in channel' measurements and tasks such as receiver alignment and fault-finding. Also useful for EMC susceptibility testing.Notoriously, the higher-frequency C & D versions of the 8648 allow you to set an output level above what the instrument can actually deliver above about 2.5 GHz, but do not provide a warning that this is happening.

author: tkamiya
author_rank: Super Contributor
timestamp: October 13, 2019, 02:04:29 am
content: Thank you.Then I'll look for 8648B with VFD, and spend accordingly.... For some reasons, they typically go for as much as and higher than 8644. Every now and then, I see bargains. It would be a good unit for my test bench.Thanks again for your reply.
Anybody want a classic HP 5245L ? - Page 1
Forum section: electronics / testgear

author: MosherIV
author_rank: Super Contributor
timestamp: October 12, 2019, 01:04:57 pm
content: The National Museum of computing is having another Electrojumble sale.Look at what I found among the items goingVintage HP 5245L precision counter.Bargin at £50Although missing the input module, worth it just for the 8 nixie tubes alone.There is also a OCXO !I see someone has restored one beforehttps://www.eevblog.com/forum/repair/repair-of-hp-5245l-nixie-frequency-counter/There is also a HP scope going for a £5Come and check it out, you might find a barginThe Electrojumble. (Sun 13Oct2019 10am to 5pm)The National Museum of ComputingBlock HBletchleyMilton KeynesMK3 6DS

author: factory
author_rank: Super Contributor
timestamp: October 12, 2019, 03:05:08 pm
content: Quote from: MosherIV on October 12, 2019, 01:04:57 pmThese will work without the plug-in modules, a blank would normally be fitted if no plug-in was supplied.Plug-ins were available to extend the frequency range, provide other functions and there was even a voltmeter one.David
B&K 2831E calibration - Page 1
Forum section: electronics / testgear

author: xxx2fan
author_rank: Contributor
timestamp: October 11, 2019, 09:18:40 pm
content: My B&K 2831E on AC reads 132.10 vac all my other meters say 122.0 vac is there a way to recal the B&K meter if anyone can help me through this it would be great.Thanks for any help