hybridfree/eevblog-posts huggingface dataset:
Bench power supply suggestions around 400-500€ - Page 1
Forum section: electronics / testgear

author: Anachron
author_rank: Contributor
timestamp: April 26, 2015, 11:06:39 am
content: Hello fellow EEVbloggers,I am looking in investing in a new bench power supply. I currently own a tripple output 2x35V/4A & 1x5V TTI supply that has served me wellfor a few years, but I would like to upgrade and use the TTI as my secondary supply. My max budget is around 400-500€. I was looking at theRigol DP832, I admit Dave's first impression video made me like it quite a lot.Searched around ebay UK and FR for used agilents and TTIs but from a first look I didn't find much around my budget.Do you guys have any suggestions? Could the DP832 software options be hackable like the Rigol scopes?Thanks in advance, have a great day
TSOP in circuit reading   tsop test clips - Page 1
Forum section: electronics / testgear

author: nandman
author_rank: Newbie
timestamp: April 25, 2015, 12:15:58 am
content: Does anyone know if you can read a tsop in circuit?Many sites say you can not but I see people selling tsop test clips to read tsops in circuit.just wondering

author: tggzzz
author_rank: Super Contributor
timestamp: April 25, 2015, 09:00:25 am
content: Quote from: nandman on April 25, 2015, 12:15:58 amLinks?

author: nandman
author_rank: Newbie
timestamp: April 25, 2015, 10:45:28 pm
content: Quote from: tggzzz on April 25, 2015, 09:00:25 amWell I was looking at the Pomona test clips and the emulation.com test clipshttp://www.amazon.com/Pomona-5514-SOIC-Clip-Test/dp/B005T617VQhttps://www.emulation.com/catalog/off-the-shelf_solutions/debugging_accessories/test_clips/tsop_test_clips/

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: April 25, 2015, 10:51:54 pm
content: Are you asking if you can read a device like an (e)eprom in-circuit?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 25, 2015, 11:56:48 pm
content: It depends entirely on the nature of the circuitry in the system it's used in.You may be lucky and the system might tristate its address bus & control lines when held in reset.Or you may be able to force enough current to override the address drivers.Or maybe not.TSOPS are easy to desolder, so using a normal socket is going to be the most reliable way.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 25, 2015, 11:59:12 pm
content: Quote from: nandman on April 25, 2015, 10:45:28 pmWhat makes you think these have anything to do with programming?The clue is in the name :testclip

author: nandman
author_rank: Newbie
timestamp: April 26, 2015, 03:35:23 am
content: Quote from: mikeselectricstuff on April 25, 2015, 11:59:12 pmHow do we locate and use the tristate? I have seen tristate mentioned when using the test clip. something about connecting tristate to ground.

author: tggzzz
author_rank: Super Contributor
timestamp: April 26, 2015, 07:42:18 am
content: Quote from: nandman on April 26, 2015, 03:35:23 amIf you don't understand how the UUT is supposed to work, then having any testclip whatsoever is a waste of time - and may damage the UUT.Applying inappropriate signals will damage something on the board. If you areluckyit will stop workingimmediately. If you areunluckyit will survive longjustenough to have entered service.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 26, 2015, 09:01:46 am
content: Quote from: nandman on April 26, 2015, 03:35:23 amLike I said, it will depend entirely on the rest of the system.
Maynuo Electronic Load serial/usb isolator - Page 1
Forum section: electronics / testgear

author: georges80
author_rank: Frequent Contributor
timestamp: April 25, 2015, 09:53:38 pm
content: I've been using my Electronic load for many months now and had to recently run some prototype pcb's. Seemed like a good time to piggy back on the run and put on an ADUM2402 based isolator for the M9812 I have.So, I have 2 spare BLANK PCB's. Below is a picture of a finished unit (the one I'm using) and also the schematic.The 2 spare's are up for grabs. Just PM for details. $5 including shipping within the US, each. Note, this is a BLANK PCB, you'll need to source the components (Digikey stocks them all). I'll provide the digikey part numbers.I 'encapsulated' the final board in some adhesive lined heatshrink - easier than putting it into a casecheers,george.

author: dadler
author_rank: Unknown
timestamp: April 25, 2015, 11:09:35 pm
content: Maybe consider uploading the board to Osh Park?

author: JBaughb
author_rank: Regular Contributor
timestamp: April 25, 2015, 11:54:02 pm
content: What does this do? Isolate the USB out from the power circuitry?

author: georges80
author_rank: Frequent Contributor
timestamp: April 26, 2015, 02:07:52 am
content: It is an isolator - electrically isolates USB from the Electronic Load. The load has non-isolated TTL level serial data. So this unit takes the TTL and electrically isolates it via the Analog Devices part and then pumps the isolated serial data in/out of the FTDI USB chip. You can buy a unit to do it - but it's $50 (or something like that) and you have to wait for delivery etc.I'm just offering the couple of extra boards I had made to anyone that wants to build up their own unit.I don't use oshpark, don't know what it is. If someone wants to put up the gerbers etc., they're attached below.cheers,george.
DSA815 option hack - Page 1
Forum section: electronics / testgear

author: K6TR
author_rank: Regular Contributor
timestamp: April 25, 2015, 08:37:14 pm
content: Has anyone RECENTLY performed the option hack to the 815. I have a machine with an older version of firmware and my attempts to unlock them are unsuccessful.

author: dadler
author_rank: Unknown
timestamp: April 25, 2015, 08:39:56 pm
content: Which firmware/boot loader are you on?

author: K6TR
author_rank: Regular Contributor
timestamp: April 25, 2015, 09:58:47 pm
content: Firmware.........00.01.05Bootloader......00.01.02
Look what came in the mail. Recommendations for cleaning.  - Page 1
Forum section: electronics / testgear

author: JBaughb
author_rank: Regular Contributor
timestamp: April 25, 2015, 04:16:37 am
content: These fine pieces got dropped off this afternoon by my friendly neighborhood UPS driver. They need to be cleaned up and a few things repaired. Some of the ball bearings are missing and a few of the dials are not lined up correctly with the numbers on the face. Everything seems to be functioning within spec though. All but the 7 decade box are 0.01%, which is way more than I need but still awesome.What would you recommend for cleaning the contacts and dials inside these things, also the banana posts on the outside?Thank you.

author: VK5RC
author_rank: Unknown
timestamp: April 25, 2015, 09:59:25 am
content: I certainly am no expert, my natural tendency would be to do the essential repairs /adjustments and if in spec leave the vitals alone, I certainly could stuff it up! HiHiPerhaps a clean on the outside. :-)

author: Grapsus
author_rank: Regular Contributor
timestamp: April 25, 2015, 10:26:29 am
content: Wow they look gorgeous, did you get them at an auction of some kind ? In Europe those dacade boxes are just out of reach in terms of prices and you don't see a lot of them on ebay.The contacts look pretty good, just turning each selector a few times should auto-clean them. I wouldn't wipe them with anything that leaves any kind of residue, maybe isopropanol if you really need to.

author: SeanB
author_rank: Super Contributor
timestamp: April 25, 2015, 11:25:40 am
content: 1 can Deoxit for the contacts, one trip to the auto parts store ( USA likely close to you) and a can of Lithium grease ( not wheel bearing or CV joint grease, you want a general purpose grease. I use Shell Cassida because I bought a 20l drum for work, and it is a nice general purpose food grade grease) for the switch mechanisms themselves. That along with new balls, which are available off the shelf at most bearing distributors, or just take a small ball bearing and crack it with a vice or grinder, will do all the repair.The Deoxit can be used on a Q tip as well to clean inside the banana plugs.For the dials use a dry fine brush, and leave it after that, unless you want to use some car wax to polish the topsides, stay away from the bottom as the paint will be very fragile.
Retro Teardown: Zhenxing DT-890 - Page 1
Forum section: electronics / testgear

author: technix
author_rank: Super Contributor
timestamp: April 24, 2015, 06:34:28 pm
content: This meter was made by Guiyang 2nd Radio Works in late 80's. Made in China at that time was some pretty solid stull, unlike now. So here it is, the meter that is older than me, which is still in active service.Face of the meter. 4.88V is the voltage of my Raspberry Pi's 5V rail.Back of the meterCase removed. Greeted with a aluminum plate shield (or I would be mooned)Noticed the fuse?My current backup meter doesn't even have that!Right side up, with shield.Shield removed.Backside, sans shield.Notice the longer screw on the COM terminal? That connects to the internal shields.Board-to-board interconnectChip porn time (and note the date codes. This unit is probably made in the lated 80s).RCA CD4030B (is 831 a date code for 1988/31w?)Maxim ICL7136 (1988/14w)Hitachi HD14011B (Hoes 8H45 stand for 1988/45w?)TI TL062 (Does 844 stands for 1988/44w? Why is the chip colored silver with black letters? Also I have several 2N7000 look like this. Why?)Intersil ICM7556 (1988/27w, this chip is not sitting in the socket properly)SS9014 (date code missing, this part is very common on Chinese-made stuff, like 2N3904)

author: electr_peter
author_rank: Unknown
timestamp: April 24, 2015, 06:42:58 pm
content: Not too bad DMM for that time, but could be better.Does it still function well? What does white potentiometer knob (above voltage terminal jack) do?

author: technix
author_rank: Super Contributor
timestamp: April 24, 2015, 06:53:40 pm
content: Quote from: electr_peter on April 24, 2015, 06:42:58 pmIt still works like a treat and it is my main meter. Maybe it need a trip to the cal lab nut still holding up actually.I have no idea what the knob is. It seem to me it have something to do with the capacitor measurement but since I have a separate LC meter I don't really use that.

author: retiredcaps
author_rank: Super Contributor
timestamp: April 24, 2015, 10:00:49 pm
content: Thanks for sharing pictures of all your meters. I enjoy seeing the construction of meters that I would not normally be able to get here in Canada.Here is the same meter, but from 1987.http://bbs.mydigit.cn/read.php?tid=870311

author: technix
author_rank: Super Contributor
timestamp: April 25, 2015, 05:21:47 am
content: Quote from: retiredcaps on April 24, 2015, 10:00:49 pmThat one's from maybe early 1988 - noticed the 1988/10w date code in the ICL7556?

author: retiredcaps
author_rank: Super Contributor
timestamp: April 25, 2015, 06:20:18 am
content: I went by the ICL7106 showing S8742. 1987 week 42.
ESR meter recommendation - Page 1
Forum section: electronics / testgear

author: Jane
author_rank: Frequent Contributor
timestamp: April 23, 2015, 07:48:15 pm
content: Can you please recommend a really good ESR meter?

author: tautech
author_rank: Super Contributor
timestamp: April 23, 2015, 07:57:33 pm
content: Recent thread:https://www.eevblog.com/forum/testgear/are-there-any-good-esr-meters-at-reasonable-prices/

author: kripton2035
author_rank: Super Contributor
timestamp: April 23, 2015, 08:22:25 pm
content: it depends the price you want to pay for it ?

author: AG6QR
author_rank: Frequent Contributor
timestamp: April 23, 2015, 09:36:21 pm
content: For what purpose?For diagnosis/repair work, if you want something to do rapid in-circuit go/no-go testing of whether an electrolytic capacitor needs to be replaced, I've used the Anatek Blue ESR meter kit. It works very well. It's not a high precision instrument, but for the purpose I described, you don't really need high precision. It's rare to see a capacitor on the border between good and bad; when they go bad, they usually go very bad very fast. Once a capacitor starts to fail, the added resistance causes self-heating, which boils the electrolyte, causing a quick death spiral resulting in a very high ESR.But if you have reason to need a high precision instrument, describe your requirements and someone may chime in with something more appropriate.
HP 3456A displaying -4.0000 in test mode - Page 1
Forum section: electronics / testgear

author: Tallie
author_rank: Regular Contributor
timestamp: April 27, 2015, 02:12:54 pm
content: Any help?

author: K5HJ
author_rank: Regular Contributor
timestamp: April 27, 2015, 05:27:26 pm
content: -4 indicates an A/D converter error. There are a lot of things that can cause this. Do you have the service manual?Randy

author: Tallie
author_rank: Regular Contributor
timestamp: April 27, 2015, 05:46:01 pm
content: Yes, and I've found all of the relevant information... which I overlooked earlier. Thanks for the help!

author: lowimpedance
author_rank: Super Contributor
timestamp: April 28, 2015, 12:58:56 am
content: As you have probably found searching that the power supplies of this vintage are the prime source of many errors.Make absolutely sure that yours is in full working order before any further speculation on faults.
HM504-2 rotary encoder problems - Page 1
Forum section: electronics / testgear

author: Hydrawerk
author_rank: Super Contributor
timestamp: April 23, 2015, 02:16:43 pm
content: The timebase knob on my Hameg HM504-2 started developing problems in late 2014.The video works fine, do not mind the grey color at preview.I should replace it in future. The scope can still be used, though. The scope was manufactured in 2007 and bought in 2008 in a sale in a second-hand store. The warranty is gone.The scope was not used very often, just a few times in a month.

author: Fraser
author_rank: Super Contributor
timestamp: April 23, 2015, 02:59:33 pm
content: I used to sell Hameg oscilloscopes in the late 1980's. They were always happy to help with problems and they still provide schematic diagrams upon request. Things may have changed under R&S management but you could ask customer services about obtaining a replacement encoder. You may be pleasantly surprised by their response.I have an oscilloscope that suffered from intermittent push button operation. I was very pleased to see the switch manufacturers part no. next to each switch on the schematic diagram. It was then easy to find the exact replacement part. Worth checking to see if Hameg have used a COTS encoder from ALPS or BOURNS.Aurora

author: Fraser
author_rank: Super Contributor
timestamp: April 23, 2015, 03:28:45 pm
content: I have just taken a look at my similar HM2005 oscilloscope schematic and have attached the relevant part as a PDF. Sadly the schematic set is slightly too big to attach.The Timebase encoder is shown as a 'STEC16B04' on the schematic. Very helpful of Hameg to provide that detail. I note that there are two types of encoders used on the scope STEC16B03 and the STEC16B04. On my scope the Y channels and Time base use the same encoder type. The only difference between the '03' and '04' is whether a click action detent is present.The STEC16B04 is an ALPS part and costs less than $5It would be worth buying some spares at that price !http://www.distrelec.ch/de/Encoder-24-24-%C3%B8-6-mm-abgeflacht-Alps-STEC16B04/p/13584673Datasheet attached. Thankfully these are not hard to find partsYou need to confirm that my scope uses the same part as yours but it is very likely that Hameg do use a part like this across their range.Let me know how you get onAurora

author: Hydrawerk
author_rank: Super Contributor
timestamp: April 23, 2015, 03:36:03 pm
content: Thank you for your advice. I do not have much time now, so I will repair it in two months or so.

author: Fraser
author_rank: Super Contributor
timestamp: April 23, 2015, 03:46:12 pm
content: At least you now know that the encoder is likely to be a nice common ALPS type and nothing custom, or hard to sourceIt is worth an email to Hameg Customer services to request your units schematics. They have never disappointed me but they do not seem to provide service manuals.Aurora
FY3212S Signal generator  - Page 1
Forum section: electronics / testgear

author: alin_im
author_rank: Regular Contributor
timestamp: April 21, 2015, 04:14:01 pm
content: hey guys,i recently find a signal generator on ebay that blow my mind...http://www.ebay.co.uk/itm/12MHz-Dual-channel-Arbitrary-Waveform-DDS-Function-Signal-Generator-FY3212S-/281537690313?pt=LH_DefaultDomain_3&hash=item418cf43ac9..it is only 80 pounds what is the catchi know it is Chinese but it dose a lot of things for its price. Is it worth it for this price or is just a knock off ? I will be using for basic stuff nothing too fancy, i am a student at the moment but i think it will help me for the next 3 - 4 years. Any how, what are your thoughts ? i Attached you the manual that they send me.

author: smjcuk
author_rank: Frequent Contributor
timestamp: April 21, 2015, 04:28:06 pm
content: If you keep your eyes peeled on gumtree and eBay you can pick up better brand units.I picked up a Thandar TG550 for £60/on Gumtree last year. There was one with a TTi triple DC supply both for £100 the other day too. Probably £800 retail.I tend not to trust anything like that unless its under £20 inc delivery.

author: Performa01
author_rank: Super Contributor
timestamp: April 21, 2015, 04:47:01 pm
content: The price seems to be plausible, considering the shortcomings when compared to the well known low-end function generators:1) Only 12 bits amplitude resolution - that would have been high-end some 20 years ago, but nowadays 14 bits is quite common.2) Only 2048 samples per waveform.3) Very high distortions, which was to expect after the observations mentioned above. Sine wave distortion of 0.8% at 1kHz is even worse than most analog function generators, which used diode networks to form a sinewave from the triangle of an RC-oscillator. On the topic of triangle waves, the FY32xxS produces one up to 6MHz, but linearity is only specified up to 10kHz and is quite bad, even at these low frequencies.4) No modulation capabilities.5) Very simplistic user interface & display.If you can live with these limitations, it might be worth buying.Yet I think you are better off saving a few bucks more and getting a Siglent SDG805 or SDG810.

author: dom0
author_rank: Super Contributor
timestamp: April 21, 2015, 04:51:37 pm
content: At 12 bits vertical res I'd expect a THD more in the range of ~-70 dB (~0.03 %). 0.8 % is very poor and worse than ... anything?

author: Obin
author_rank: Contributor
timestamp: April 23, 2015, 09:40:27 am
content: I have a similar unit, but with the FY2105S.No complaints. It doesnt have the quality and features of a 2000 dollar unit, but then again, it isn'tIt delivers a decent signal in my opinion. The only thing i had to remove was the beeping sound it makes with every interaction.If you're looking for a cheap signal generator, i'd say these units are worth it.
Fluke Service - Page 1
Forum section: electronics / testgear

author: kasone
author_rank: Contributor
timestamp: April 22, 2015, 01:59:13 pm
content: Hi, This is my first post. I have been following EEV blog posts about DMMs for a while and decided to share my experience with Fluke service. I purchased a factory reconditioned Fluke 76 direct from Fluke in the 1990's. It was sent back for a display problem. They replaced the display and calibrated it in 1997. It still reads accurately with the Fluke 83V that I use at work. I have had no further problems with the 76. I recently acquired a non working Fluke 177 and sent it to Fluke for service expecting a bill because the battery door was missing, fuses open, beeper not working, probes would not insert easily into the volt jack, and backlight not working. I received it back in less than 10 business days and they covered it under their lifetime warranty. They replaced the circuit board, battery door, and beeper. It works perfectly. all 3 flukes that I use compare very closely in readings.I have purchased and used other meters, but the Fluke meters give me a feeling of being accurate, well built, and their service is next to none in my opinion.This is just my experience from working in electronics for over 30 years.

author: Lightages
author_rank: Unknown
timestamp: April 22, 2015, 06:21:26 pm
content: That is exemplary service. I don't think any other company I have dealt with would have done that. Well maybe Leatherman but they don't make multimeters, just multitools!

author: KeepItSimpleStupid
author_rank: Regular Contributor
timestamp: April 22, 2015, 07:09:24 pm
content: I could not even get a simple battery door for a Fluke Networks Toner without sending it in for full repair.

author: H.O
author_rank: Frequent Contributor
timestamp: April 22, 2015, 08:25:51 pm
content: My single experience with FLUKE service:A couple of years ago I got a 79-III from the dumpster at work. I don't remeber what the actuall issue with it was but it wasn't working properly.So I thought I'd see what that "Lifetime warranty" stuff was all about and contacted FLUKE. Was told to send it in for investigation and that if they determined that the meter was damaged by abuse they'd charge me a fee for the investigation and give me with a quote for the repair. If the problem wasn't likely to been caused by abuse they would take care of it.So, it was a bit of gamble really since I could've been charged more than the poor old meter was worth but I sent it in. A couple of days after later they got back to me and said that the problem couldn't have been caused by abusing the meter and asked if I'd accept a brand new 175 in return since it wasn't really worth reparing the 79-III. I didn't mind that...
uCurrent Gold oscillate on 1mV/nA range? - Page 1
Forum section: electronics / testgear

author: paul.gaastra
author_rank: Newbie
timestamp: April 09, 2015, 01:34:03 am
content: Hi, We have a uCurrent Gold from the Eevblog shop. On the 1mV/nA range I get an irregular approx. 40kHz oscillation.This is with a 12V battery in series with a 10M resistor.Anyone experienced the same thing?Any fixes?Thanks

author: EEVblog
author_rank: Unknown
timestamp: April 09, 2015, 02:22:40 am
content: It will be your setup, most likely picking up noise from somewhere. proper low current measurement is not a trivial thing to do.

author: KeepItSimpleStupid
author_rank: Regular Contributor
timestamp: April 22, 2015, 08:40:00 pm
content: What I would try to do is to add a polyester or polystyrene cap across the combination of R3 and R11 (98K) such thatf = 1/(2*PI*98,000*C) where f is the -3 db frequency and C is the capacitance in Farads. f would be much greater than the frequency of interest.If not interested in high frequencies the MAX4238 is unity gain stable and reduces the GBW to 1 Mhz. GBW = Gain*Bandwidth.At low currents, the system could be affected by the tribolectric effect. Motion of the conductors will cause currents to flow.40 kHz could very possibly be the frequency of a CFL lamp and thus you could be picking up transmissions from that or a computer fan.Shielded cables have capacitance and can be more prone to oscillations.Low current measurements are easy to set up, if you know what you have to watch out for. I set up a system to measure below 2 pA without Dave's device.With these measurements, a shielded fixture is used and a shielded and guarded conductor is used. Specifically Triax cableing which has two shields and a center conductor. 1 meter of this cable with connectors is >$100 USD. The gaurd is "driven" at the same voltage of the inner conductor, so leakage to the shield does not take place. The fixture is guarded/ driven at the center conductor voltage.Measurements are sensitive to the piezoelectric, triboelectric effects ad EMI and RFI.What type of 10 M resistor are you using? Think of what might be nearby that operates at 40 Khz. Do the measurement outside with the wires secured or use thick wire so they don't move in the wind.
Suggestion for dual output power supply, 0-15V, 5A minimum on both channels - Page 1
Forum section: electronics / testgear

author: uoficowboy
author_rank: Regular Contributor
timestamp: April 22, 2015, 01:11:35 am
content: I need to grab one or two dual output power supplies for work. They need to be modern and reliable. 15V, 5A out is a minimum. I'd rather see more like 30V, 10A out. Volume is a major concern. Banana jacks on the front are required.Currently we're using theKeysight U8031A. They're... OK. They're a bit loud and the internal build quality is not what I expect from Agilent, so I don't really think it'll last forever. Does anybody have a better suggestion? Reliability is key here, so I'm very nervous about the various Asian brands that are popular. Budget is $1500ish each.

author: smjcuk
author_rank: Frequent Contributor
timestamp: April 22, 2015, 06:34:10 am
content: TTi do some nice supplies with those specs:http://www.tti-test.com/products-tti/psu/psu-bench.htmThey're absolutely bomb proof as well.
Lab Calibration Results - Page 1
Forum section: electronics / testgear

author: RoboTechEd
author_rank: Regular Contributor
timestamp: April 21, 2015, 03:22:02 am
content: Hi All,In another thread I mentioned getting in a DMMCheck Plus to calibrate all of my test gear (link). I got it in today, and measured all of my test equipment to see what was within spec and what wasn't. I have compiled the data below in a google doc spreadsheet. I figured I'd share it here because everyone loves more dataInteresting Findings:-My $10 pocket multimeter is one of my most accurate-The old Fluke-8012A is still well within spec (incredible considering the age)-All meters seemed to struggle most with the lowest resistance/AC Voltage/CurrentNext step: Calibration!Feel free to chime in with suggestions/critiques.https://docs.google.com/spreadsheets/d/1iuMLSG44whJUPThB31mjJ63v_EDOB1AnHA3-22toGvg

author: ElectroNub
author_rank: Contributor
timestamp: April 21, 2015, 04:04:26 am
content: pictures or it didn't happen!

author: Dave
author_rank: Super Contributor
timestamp: April 21, 2015, 04:08:16 am
content: Variance and error are two entirely different things.Measuring a square wave with a non-RMS meter will not yield the correct result. If you want to see the actual measurement error, you need a sine wave.

author: RoboTechEd
author_rank: Regular Contributor
timestamp: April 21, 2015, 04:43:13 am
content: Quote from: Dave on April 21, 2015, 04:08:16 amYou are correct. I updated the spreadsheet. oops! Also, All of the meters were RMS meters luckily, besides the Knight DMM. I highlighted those results red to imply to look at the notes. I do think 5.55v is an accurate reading though for a 5vpeak square wave. I just checked on the DMMCheck site, and they confirmed that. Also, it was surprising that so many of my cheap meters were RMS!Quote from: ElectroNub on April 21, 2015, 04:04:26 amWhatya want pics of? The results? I guess I could have made the data up without photographing the equipment's screens....Guess we'll never know
Hako ?? What model - Page 1
Forum section: electronics / testgear

author: sam coniglio
author_rank: Newbie
timestamp: April 20, 2015, 09:11:27 pm
content: I need a dedisoder station.nothing fancy just reliable and replacement tips that are ceap.I mainly work with see-trough old school printed pcbs.I used to Pace decoder station. It really sucks but the heat element does not work anymore. I have a million tips and accessories for it.However I want to give Hako a tryany suggestions on a model? the many choices are overwhelming.Sam

author: nanofrog
author_rank: Super Contributor
timestamp: April 20, 2015, 09:59:01 pm
content: Where are you located?If you go into your user profile and set your country, the flag will be displayed beneath your userID. Makes it so much easier and faster for everyone if you do, particularly regarding relevant links for products & pricing.Regarding a desoldering tool, if your Pace is otherwise functional as indicated, you'd be better off replacing the heating element. Particularly as Pace makes really good quality products, nor should you underestimate the expense of consumables (filters & nozzles add up).Past this, your location is necessary for relevant links.

author: generatorny
author_rank: Newbie
timestamp: April 20, 2015, 11:02:28 pm
content: Have two of FR-300 and three 808 (two died in last three years)Hakko FR-300 works great. For around $300, in my opinion you can't buy anything that good. It is a Hakko 808 successor. Which in my opinion was average grade desoldering tool.Fr-300 has easy to change tips with some improvements in tip design (coating and durability). Found that 1.3 mm works great for regular size eyelets, 0.8 and 1mm can be hard to work with, specially with 20 -30 year old circuit boards.Suction power is better than older version, only downside is design of ceramic cartridge (seems loose inside the filter pipe).I have set temperature to medium (right in the middle) and I am able to work with multilayer boards without any problemsTurn of when not using it, it saves tip as well as heating element.In the past I have used various brands of desoldering tools from Pace, Weller and Denon, and FR-300 works better.Hope this helps
FG-100 DDS function generator, need help please - Page 1
Forum section: electronics / testgear

author: generatorny
author_rank: Newbie
timestamp: April 17, 2015, 01:21:28 pm
content: Hi guys,I need some advice, I got cheap FG-100 DDS of Ebay and did not notice that it range is from 1 Hz to 20 kHz. For my application I need only range between 0.1 Hz and 1 Hz. Is it possible to make some changes internally or I just wasted my money. Any help is appreciated.Cheers

author: deephaven
author_rank: Frequent Contributor
timestamp: April 17, 2015, 04:19:39 pm
content: Quote from: generatorny on April 17, 2015, 01:21:28 pmIf you just wanted a square wave, you could wire up an external divide by ten counter and feed the counter with the FG-100.

author: Kleinstein
author_rank: Super Contributor
timestamp: April 19, 2015, 07:34:05 pm
content: This one looks like a µC (likely AVR) doing DDS in Software. Without a circuit plan it is a little difficult so say how to modify it. In Principle there are 2 methods to lower the frequency:1) change the Hardware - e.g. change the crystal to a slower one.2) change the software - there are man similar projects out there, and some even provide software including source code, so one could adapt it to a slightly different hardware (e.g. different pins used). However a first step for this would be finding the circuit. If the µC is in a socket you can start over with a new and keep the original as Backup. You also need a programmer Hardware - unless you have this, this wold be the hard way.It is possible that the amplifier uses AC coupling, though 1 Hz is allready quite low. If so a larger capacitor may be helpful.

author: generatorny
author_rank: Newbie
timestamp: April 20, 2015, 04:32:13 pm
content: Yes lowering the frequency of oscillator did the trick. I went from 30Mhz to 5.0688Mhz and did not affect quality of sine wave much, and my output is proportional to oscillator change so it went from 1Hz down to 0.17Hz which is what I need.Guys thanks for the input.Cheers
Service manual or calibration tips for my old Tektronix 2211 scope? - Page 1
Forum section: electronics / testgear

author: cdev
author_rank: Super Contributor
timestamp: April 20, 2015, 01:34:45 pm
content: Hello,A bit less than a year ago I purchased an old Tek 2211 for a bit less than $100 which even uncalibrated has been really useful for me. Over that time I have been looking for a service manual for it. I have manuals for some similar models but none of them appears to be quite adequate for what i would like to do which is replace any capacitors that are out of spec and calibrate it. For the most part it seems close enough for a lot of what I do but there is no substitute for following the manufacturers procedure so I could have confidence in it as a measurement tool. The worst thing that I found which is clearly out of calibration is the "1 khz" square wave - which is now 991 Hz.Does anybody know where I could find the service manual or whatever info I would need to calibrate it and deal with anything that is out of whack?Its a fine scope, its not too large but it clearly is a good quality construction, the CRT appears to be in decent shape and I would love to fix it up a bit (perhaps with a quieter fan) so I could get many years of use out of it. It has the 500 uv range which makes it a very useful tool for a lot of things. It even has a RS232 port so it can send screen captures to a serial port in HPGL.Thank you!

author: sync
author_rank: Frequent Contributor
timestamp: April 20, 2015, 06:37:43 pm
content: Quote from: cdev on April 20, 2015, 01:34:45 pmThat's ok. It's specified 1kHz +/-20%. For probe adjustment an accurate frequency is not needed. It's probably not adjustable anyway.About the service manual. You can buy it fromhttp://artekmanuals.com/.But you can look at manuals from similar Tek scopes (2212?) first. To get an idea how to adjust these scopes and what equipment do you need.Before adjustments or replacing components do the performance verification tests. If it's not broken, don't fix it.
Extech 382260 Fault - Page 1
Forum section: electronics / testgear

author: tgdavies
author_rank: Newbie
timestamp: April 20, 2015, 06:39:18 am
content: I have an Extech 382260 bench power supply. I have not used it much, but it has worked fine.Last night I had it set to 12V 1A and was powering a LiPo battery charger which was drawing about 800mA. Suddenly the charger turned off, and I saw that the power supply was providing about 4V at 10mA.Turning the output of the PS off and on turns the charger on for a moment until the overcurrent cuts the voltage again, so it can supply the current.Turning the output off, holding down 'review' and turning the 'current' knob does nothing -- the set current fluctuates between about 5 and 20 mA.I've tried unplugging the PS and using different ranges.The charger is fine -- I'm now using it from a wall wart which provides 12V at max. 1A and it's charging a 2S LiPo at 1A.Any ideas about what might be wrong, or what else I can try.Thanks,Tom
Rigol DM3068/3058 RFI-emission problem... - Page 1
Forum section: electronics / testgear

author: Co6aka
author_rank: Unknown
timestamp: January 06, 2015, 07:40:08 pm
content: If anyone has a DM3068 or DM3058, please check your instrument for RFI-emission with scope and spectrum analyzer. From its test leads, mine is emitting quite an RF hash; probing either lead with my scope shows a nasty looking but slightly different waveform, and changing test mode changes the waveform slightly. Wondering if mine has a problem, or if Rigol has a problem. Will try to post waveforms later.

author: Omikron
author_rank: Contributor
timestamp: April 03, 2015, 12:18:25 am
content: Did you ever end up figuring out what was going on here? Do you still have photos of the waveforms?

author: mcinque
author_rank: Unknown
timestamp: April 03, 2015, 08:34:46 am
content: Found nothing on the probes, can you be a little more specific about the frequency?

author: Omikron
author_rank: Contributor
timestamp: April 23, 2015, 07:11:16 pm
content: Just checking in again, as I am about to buy a DM3068. Has anyone else been able to duplicate these symptoms?
parallel connection for hp 6205b - Page 1
Forum section: electronics / testgear

author: lukaq
author_rank: Regular Contributor
timestamp: April 22, 2015, 06:32:01 am
content: Hey,I have a problem, i'm not too sure how to make outputs share current, I was able to get voltage tracking, but channels don't want to source the same current, one is what it is, other is around 0For voltage track, you have A6 os slave connected to +, S+, A10 and GNDSlave still has +, S+ and A10 shorted, A7 floating as is A8I can't connect S+ master to S+ slave, since slave will sink some current

author: macboy
author_rank: Super Contributor
timestamp: April 22, 2015, 01:40:52 pm
content: When doing parallel connection, it is common for one supply to source all current, until it reaches the current limit, when the other one will start to source the excess. This is because one will have a slightly higher output voltage that the other (even if set to the same voltage). This causes the slightly lower one to completely turn off since the output voltage is higher, even if only slightly, than it is trying to maintain. When the first one goes to current limited mode, its voltage will drop, and the second one will begin to source current.If you really want to share current equally, then you can use ballast resistors between each supply and the load. Even just a long cable (2+ meters) can do well enough. Don't connect one supply to the other one, then one set of cables from it to the load; connect each supply to the load through its own cables, and make those cables the same for each supply. The accuracy of the current sharing will depend on how precisely the output voltages and the cables (or resistors) are matched.

author: lukaq
author_rank: Regular Contributor
timestamp: April 22, 2015, 06:35:41 pm
content: Sure, this all makes sense. But what I have seen (could be because i didn't fully connect it right or something) is, that one channel (primary) hit current limit driving led and other channel did nothing to output any current (even sink 10-20mA from the first one)
Buying Amazon equipment for use in Australia - Page 1
Forum section: electronics / testgear

author: Zalgar
author_rank: Contributor
timestamp: April 19, 2015, 05:16:53 am
content: On Dave's amazon store there is a couple pieces of equipment that I would like to acquire, its much cheaper on amazon, even when converted from USD to AUD.Im wondering if the scopes and power supplies can be used with australian outlets, or do I need an adapter/different cord/ a converter of some sort for use.Cheers.I should probably add, the devices are:Rigol DS1054ZBK Precision 1670A

author: deadlylover
author_rank: Frequent Contributor
timestamp: April 19, 2015, 05:49:57 am
content: Both will work, just remember to change the line input setting on the BK Precision to 230V, the manual says the switch is on the bottom of the unit. You'll need new kettle cords if you don't have any spare, but they're only a few bucks each.

author: Zalgar
author_rank: Contributor
timestamp: April 19, 2015, 06:07:42 am
content: Ah excellent, thanks for that.

author: firepower
author_rank: Regular Contributor
timestamp: April 19, 2015, 08:49:54 am
content: They don't ship Rigol DS1054Z to Australia
Tektronix P6139A Probe Cable - Page 1
Forum section: electronics / testgear

author: skennedy
author_rank: Contributor
timestamp: April 19, 2015, 07:02:37 am
content: I have recently found that one of my Tektronix P6139A probes has stopped working. Disassembly of probe has revealed that the cable has become an open circuit. I have tested the rest of the probe and it works fine when I swap in a cable from another probe. Obviously I'm not going to be able to just easily repair the cable to an acceptable level (let alone located the fault) so I wonder if I can find a cheaper replacement cable than having to buy a replacement probe. There are heaps of different Tektronix probes that appear to have very similar probe cable assemblies and wonder if anyone knows if another probe has a cable that will work with the P6139A attenuator and compensator?Thanks for your help,Simon
Fluke High Voltage Probe Tip - Page 1
Forum section: electronics / testgear

author: Excavatoree
author_rank: Frequent Contributor
timestamp: April 17, 2015, 01:38:43 pm
content: Because I am often after the "bargain basement" Fluke meters, I have a collection of high voltage probes (The ones that come with many 27s) that are missing the tip. I can't seem to find any of them for sale, so I am considering having some made. (Please excuse the crudity of my computer model, it IS to scale, but I didn't have time to paint it. )The problem is, I'd have to get more than I need made to get the cost down. I'm seriously doubting I could sell 5-10 of these things, but I wanted to get some other opinions. Most of the members here are in electronics and don't use these probes, but is there anyone who would purchase spare/replacement tips, and if so, what would you be willing to pay? I know the entire probe can be found for 50-100 dollars by themselves, and more economically for 60-100 with a Fluke meter, so I know it isn't very much. I fear this is a useless and uneconomic endeavor, but I thought I'd at least explore it.

author: HighVoltage
author_rank: Super Contributor
timestamp: April 17, 2015, 05:10:27 pm
content: You are probably talking about the Fluke 80K-6 and higher modelsI have one of those but the metal tip seems to be the strongest part of the probe and usually does not get lost. So, you probably do not find a real market for these, as you pointed out already.But the metal tip is easily made on a lathe and should not cost much at all, even for a couple of them.Tolerances are not so important.

author: Lightages
author_rank: Unknown
timestamp: April 17, 2015, 11:43:28 pm
content: I would make you a couple for free, except the shipping from Chile to the US would be $30. The cheapest thing to do is find some screws with the same thread, cut the heads off, file the end to a ball, and fix them in place with a nut.
Digitech Qc 1920 scope - Page 1
Forum section: electronics / testgear

author: Jbliss
author_rank: Regular Contributor
timestamp: April 18, 2015, 02:12:27 pm
content: anyone got any manuals or design for this PleaseDigitech Qc 1920 scope 10mhz Single channel CROThanks

author: Guni
author_rank: Regular Contributor
timestamp: April 18, 2015, 02:34:26 pm
content: Check this treadhttps://www.eevblog.com/forum/testgear/digitech-qc-1922-oscilloscope-schematic/
Replacement HP/Agilent/Keysight kit foam? - Page 1
Forum section: electronics / testgear

author: darrell
author_rank: Regular Contributor
timestamp: April 16, 2015, 09:09:54 pm
content: I got a HP 11752D 3.5 mm connector gage kit today and of course it has decaying foam. Fortunately it wasn't too bad and all the parts cleaned up with a bit of isopropyl.I tried Keysight for replacement foam and they still have parts for the kit, but no foam. Any suggestions for replacement? Something fairly dense that could be layered and cut with a knife would be good. I found one place that does laser cut foam but it seems to be a minimum of $50.

author: Neganur
author_rank: Unknown
timestamp: April 16, 2015, 09:56:27 pm
content: No idea. It's also a frequent topic on the Agilent and Tektronix mailing lists.I guess if it's not static sensitive you could get away with using the dense insulation foam used in houses.

author: dom0
author_rank: Super Contributor
timestamp: April 16, 2015, 10:28:45 pm
content: How about ESD-safe PUR foam?

author: darrell
author_rank: Regular Contributor
timestamp: April 16, 2015, 11:18:27 pm
content: I ordered this. Ugly but cheap and anti static.http://www.ebay.com/itm/251920290317?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Value of Fluke 192C? - Page 1
Forum section: electronics / testgear

author: zaoka
author_rank: Frequent Contributor
timestamp: April 13, 2015, 05:49:26 pm
content: Does anybody know what is the real value of Fluke 192C, brand new condition?

author: Gribo
author_rank: Frequent Contributor
timestamp: April 13, 2015, 06:07:05 pm
content: A new 192C Scopemeter is around 1800USD, depends on your location. Pay attention, the battery packs (NiMH) tend to die after a couple of years and can prevent the scope from working (It will work without the pack and with external DC power).

author: zaoka
author_rank: Frequent Contributor
timestamp: April 13, 2015, 06:16:01 pm
content: How reliable are these? Are they worth keeping?

author: zaoka
author_rank: Frequent Contributor
timestamp: April 17, 2015, 12:29:53 am
content: Nobody uses these?

author: noidea
author_rank: Unknown
timestamp: April 17, 2015, 02:34:33 pm
content: Quote from: Gribo on April 13, 2015, 06:07:05 pmHi Gribo Is it just a case of fitting a new battery pack or are there any other things to watch out for? I'm looking at buying a 196c that's been in storage for a while with a dead battery but it does power up on mains.

author: LaurentR
author_rank: Frequent Contributor
timestamp: April 17, 2015, 04:34:20 pm
content: I had a 192B (B&W) for a while.This thing had 2 significant and one mild advantages:* It's portable. IIRC I had to change the battery.* The inputs are fully floating catIII rated. So for everyday tasks, it removes the need for a differential probe and you can play with mains / SMPS safely.* It also works as a DMM.Apart from that, it is nowhere near any modern scope in terms of functionality.For a few $100s (bought mine $500 on EBay), it was worth having around (although I sold it after a couple of years of rare use past the initial novelty). At $1800, except if you absolutely need the portability and isolated inputs on a regular basis, I wouldn't do it.
Agilent E7495A/B Hacking - Page 1
Forum section: electronics / testgear

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: April 16, 2015, 07:47:41 pm
content: Since I'm apparently not the only owner of an Agilent E7495 BTS Test Set, did any of the other owners make any progress in terms of hacking that thing?What I'm particularly interested in is if the predefined waveforms for the AWG can be replaced by less cellphone centric waveforms, or if the built-in speaker could be enabled for demodulation.If we're at it, maybe someone can find a way to prevent the screen capture setting reverting to white backgroundDid anyone make any progress?
not just another cheap thermal imager, HemaVision - Page 1
Forum section: electronics / testgear

author: ebeall
author_rank: Newbie
timestamp: April 15, 2015, 03:33:08 am
content: Hey all, following the intense Mu and Seek discussions here, would like to announce there is another thermal imager on Kickstarter now athttp://kck.st/1C6gXtg(disclosure: I'm one of the guys, ahem, people behind it).The HemaVision is less than the Lepton dev kit at Sparkfun (https://www.sparkfun.com/products/13233) by quite a bit (not to knock Sparkfun or Pure Engineering - they're both excellent), and it includes a screen, a shutterless 82x62 thermal diode array (never needs recalibration, very much like a thermopile array), battery, case, image sensor, quad-core processor and Wifi module. Its real, and it will ship in October of _this_ year. Please feel free to comment and ask questions.Erik

author: efahrenholz
author_rank: Regular Contributor
timestamp: April 16, 2015, 06:01:25 pm
content: Are you using an off the shelf developed sensor or is this something you designed? This is quite an undertaking, especially considering the image quality compared to the more conventional 80x60 lapton core. Your images look cleaner than the Seek developed sensor... Of course you also list the NetD, which they have all but forgotten that they even sell a thermal camera.
Try To Hack My Flir E4!! - Page 1
Forum section: electronics / testgear

author: elplome
author_rank: Newbie
timestamp: April 16, 2015, 11:02:37 pm
content: I'll tried to hack my flir e4 but i have a little trouble!now when i connect the e4 to the computer show me not the Flir Usb Video just a name like a network of internet something like that !if someone can help me ill appreciatethank