hybridfree/eevblog-posts huggingface dataset:
slow signal triggering fails with DSO Tek TDS-420 - Page 1
Forum section: electronics / testgear

author: gotnoise
author_rank: Newbie
timestamp: June 15, 2013, 02:14:03 am
content: I just treated myself with a Tektronix TDS-420 from ebay (vintage digitizing scope, 150 MHz, 100 MSa/s, 4 channels). I quite like it, and it is surely one of the better pieces of equipment on my beginners bench. But I have a little problem when trying to trigger slow signals. For some of my projects, I am working with signals at 1-100 Hz. And I am not able to trigger them properly with the TDS-420. When I switch to anything above 20 ms/dev (next step for this scope is at 50 ms/dev), triggering fails, and the scope switches to rolling (untriggered) mode. I fed the scope with an external function generator, and the problem seems independent of amplitude (0.1 - 5 V) or waveform (sine, sawtooth, square wave) of the input. Also, I could not get it to work by feeding the sync output from the waveform generator into channel 2, and then triggering from channel 2. I assume, the scope is simply not capable of triggering at that slow time base. Is this normal, and am I asking for too much? I don't quite understand why a slow time base would limit the trigger function. Also, is there a trick to overcome the problem? Just pressing the stop button to look at the frozen signal is not good enough for my purpose.Thanks a million for any input!

author: Bored@Work
author_rank: Super Contributor
timestamp: June 15, 2013, 05:57:12 am
content: The manual says two out of its four roll modes trigger, two are untriggered. Check the manual to see how to switch between roll modes.

author: gotnoise
author_rank: Newbie
timestamp: June 15, 2013, 02:38:05 pm
content: Thanks for your feedback, bored@work!My TDS420 has only two roll modes (auto=untriggered roll & normal=triggered roll). I did find your reference to 4 trigger modes in the manual for the TDS420A. There, it explicitly states that at 50 ms/div and slower, roll mode can be turned off. Unfortunately, in my TDS420 this option does not show up in the menu. I could not find a menu for the 420, only for the 420A. But I assume that the difference between the 420A manual and the 420 menu functions has to do with the older 420 version. Maybe a firmware upgrade would fix this problem. My current firmware version is FV:2.5e. I could not find any firmware upgrade yet, but I will keep looking for one.
Measuring scope channel skew and cable velocity with Jim Williams pulser - Page 1
Forum section: electronics / testgear

author: jpb
author_rank: Super Contributor
timestamp: June 15, 2013, 12:53:02 pm
content: Sorry for the long title, but this is two experiments in one.I've been having a lot of fun with my Jim Williams pulse generator (thanks Free_electron/Vince for the kit). One experiment that I've just done is to use it to measure both the velocity of signals in my coax cable and at the same time get the channel-to-channel skew in my scope at the 1ns/div scale. I hope this will be of interest to others who have got bored of just measuring the rise time.SetupVery simple. I have a bnc t-connector and three bnc cables whose end-to-end lengths are 1017mm, 535mm and 268mm (standard cables I bought from Conrad I think).I connect the pulse via a sma-to-bnc adapter to one of the t-branches and a cable to the other. The t is then connected to either channel 1 of the scope or channel 3 and the other endof the cable connected to channel 3 or channel 1.The scope display then shows a pulse and delayed pulse and the delay can be easily measured. To allow for channel skew the delay is measured from 1 to 3 and then from 3 to 1 and the difference in delay is twice the skew (adds one way and subtracts the other).The slope of the delay vs cable length line gives the velocity at 2.01005 E 8 m/sec or 0.67048 c (where c is the speed of light).The skew shows a roughly linear relationship with delay varying from 50 psecs for no delay to potentially 130 psecs for 10 nsecs delay - by extrapolation, the actual skews Imeasured were 60, 70 and 90 psecs.I attach the screen shots and plots.
TDS 540 problem II - Page 1
Forum section: electronics / testgear

author: vaualbus
author_rank: Frequent Contributor
timestamp: June 08, 2013, 12:55:59 pm
content: In relation to my previous forum I make another one.Now I've replaced both the TVS diode and Q9 and now I have a bias voltage of 15, sweat!.Unfortunally the psu still doesn't work, it have no output from the transformer and for some reason the 12V bias is 15V. This is no strange because the service manual refer to 12V bias voltage to a rail that than is ratet to 14.65V. (See the picture below for more detail).I also post the A19 board schematics.There some common failure on the A18 board that is the switching part of the psu?There some else to check to make sure that everything is ok?

author: vaualbus
author_rank: Frequent Contributor
timestamp: June 13, 2013, 08:23:07 pm
content: Jus to in form people out there finally I replace UC3525A nad boom now it work!!!

author: nctnico
author_rank: Super Contributor
timestamp: June 13, 2013, 11:04:26 pm
content: That is a pretty uncommon failure. Usually the controller chip is about the last thing that fails. In other words: very good find!How is the rest of the scope?

author: vaualbus
author_rank: Frequent Contributor
timestamp: June 14, 2013, 03:55:15 pm
content: Ya I also think so but I'm luck finding this error.My thought is that the chip not techical wrong a part from the internal 5V ref that read 0.

author: vaualbus
author_rank: Frequent Contributor
timestamp: June 14, 2013, 04:11:45 pm
content: For the rest of the scope, see the TDS540 problem III
Best 2-ch lab supply in 200 euro range - Page 1
Forum section: electronics / testgear

author: mrkva
author_rank: Unknown
timestamp: June 12, 2013, 10:17:59 pm
content: Hello,since my beginners-lab is starting to require some solid power supply, I am looking for some 2ch power supply (I need 2ch because I use a lot of +/- 12V). Any tips?Shouldn't be above 200 euros (260$).Thank you!

author: Paul Price
author_rank: Super Contributor
timestamp: June 13, 2013, 02:26:31 am
content: Build your own and save a ton of money. There are many topics here about that, some from me, others from others.

author: uoficowboy
author_rank: Regular Contributor
timestamp: June 13, 2013, 05:58:04 am
content: If you don't want to build your own, I'd find a nice used one. $200 is way more than you need for a 2 channel power supply on Ebay. There's a lot of old HP and Power Designs gear on Ebay going for awesome prices. I got a Power Designs TW5005W on there (2x 50V, 0.5A). Definitely my favorite power supply that I own (and I have something of a collection...) I think I paid about $75 and all it needed was a couple capacitors and a little cleaning.

author: mrkva
author_rank: Unknown
timestamp: June 13, 2013, 06:21:22 am
content: Yes, I considered building my own, I even have two home-built ones. But I wanted something with a display, current limiting, etc.. And also, I worked for my friend, and as a reward he offered me he would buy me (new) one.Thanks for the tips

author: Unknown
author_rank: Unknown
timestamp: June 13, 2013, 07:27:01 am
content: Instek Totally recomended...http://www.gwinstek.com/en/product/productbcategory.aspx?pid=38but in the $200eu range?Instek SPD-3606 is the best Switching D.C. Power Supply, but is in the $8OOusd. range.GPS-x303 Series, best toroidal linear DC Power supply,the gps-4303 is in the <$8OOusd range.theGPS-2303is in the <$4OOusd range. fits the bill.GPC-Series are classic EI transformer design (the only brand with selectable input voltage 110v,120v,220v,240vac), top quality.you may want to ask yourself, if you want more AMPs,_? More Volts,? or more Displays.?GPC-1850D = (0~18V/0~5A)x2 + (5V/3A)x1, 3-channels.GPC-3030DGPC-6030DGPC-3060DGPC-3030DQ...or you can buy singles and link the controls, displays & outputs serial or parallel, there´s no need to be a 2-ch, unit.many options available....EI transformer or switching.many voltage & amp. ranges,from the popular GPS, to the super expensive GPR-U.SPS are switching.GPS-xx0D are the EI.
Is Fluke 80 series rotary knob with plastic shaft common? - Page 1
Forum section: electronics / testgear

author: retiredcaps
author_rank: Super Contributor
timestamp: June 11, 2013, 06:20:06 am
content: I managed to break a Fluke 80 series rotary knob with plastic shaft while taking it apart.It was from a Fluke 87V firmware 1.0.1, rev 9 board.I have taken 4 or 5 Fluke 80 series rotary knobs apart and they have always been steel/metal until now.Anyone else notice a plastic shaft on their series 80?

author: ron
author_rank: Regular Contributor
timestamp: June 12, 2013, 01:22:53 am
content: You are right. The shaft that used to be metal on previous 80 series meters is now plastic. Last year a friend somehow broke the selector dial on his nearly new 87V. I replaced the a broken plastic shaft with a metal one machined from a piece of hex stock (think allen wrench). It was kind of a tricky repair to seat, secure, and center the new shaft into the dial it but turned out well. The meter is in daily use and no problems so far.

author: retiredcaps
author_rank: Super Contributor
timestamp: June 13, 2013, 06:47:12 am
content: @ron, thanks for the feedback and your repair suggestion.
Is This Serious ? Where Does this Equipment Come From !! - Page 1
Forum section: electronics / testgear

author: Unknown
author_rank: Unknown
timestamp: June 12, 2013, 08:01:18 pm
content: A picture saves a thousand words, or so it's said... just wondering about this E-Bay seller, from Israel;I'm puzzled about the duff equipment this seller seems to sell, typical example below:http://www.ebay.co.uk/itm/Wavetek-271-Digital-Programmable-Pulse-Function-Signal-Generator-/150945889024?pt=LH_DefaultDomain_0&hash=item2325137b00

author: eevblogfan
author_rank: Frequent Contributor
timestamp: June 12, 2013, 08:05:29 pm
content: nothing about israel my friendthis seller seem to be superbly ass , and the test gear might come from secret program I musn't tell you the nameAnyhow , don't buy this things unless you know wat your doing

author: gregariz
author_rank: Frequent Contributor
timestamp: June 12, 2013, 08:12:14 pm
content: I have purchased from that seller. He often lists RF equipment. Alot of it appears Military surplus. I've even seen stuff with bullet holes in it.

author: Unknown
author_rank: Unknown
timestamp: June 12, 2013, 08:23:29 pm
content: Quote from: vlf3 on June 12, 2013, 08:01:18 pmmany people or out of business or retired companies throw in the trash old equipment, recyclers sell it to electronic collectors & resellers, and they resell it again.haven´ t heard, some ones trash is someones else treasure?in my country there is a whole shopping mall of vintage electronics + a museum filled with old stuff, mostly unknown equipment, or not the ones i want,crazy stuff i´ve seen there, from Geiger counters to x-ray tubes, to am radio frequency generators, photo cameras, video & film, vintage oscilloscopes, damaged ramsa consoles, reel to reel stuff mostly sony, hp generators, etc...it was aired in some tv show/chapter in Discovery Channel or NatGeo can´t remember.i´ve seen trash quality imacon 848 on ebay for $4000usd., like new ones sell for $6000usd., did it sold? i guess not.

author: don.r
author_rank: Frequent Contributor
timestamp: June 12, 2013, 08:28:14 pm
content: There's a whole thread on here about some of the STM stuff. The one listed by the OP looks fairly good in comparison to some of the stuff they sell.

author: saturation
author_rank: Super Contributor
timestamp: June 12, 2013, 08:35:12 pm
content: He's a character no doubt:https://www.eevblog.com/forum/suggestions/blog-suggestion-repair-of-the-odd-random-ebay-'untested'-purchase/msg90816/#msg90816

author: Unknown
author_rank: Unknown
timestamp: June 12, 2013, 09:22:35 pm
content: Quote from: gregariz on June 12, 2013, 08:12:14 pmyou make me remember the video of someone shooting a vintage drum machine...sadly the video was removed jajajajajahttp://www.synthtopia.com/content/2008/10/18/crazy-half-naked-man-dirty-harrys/
3Vpp switching noise on switchmode bench PSU - Page 1
Forum section: electronics / testgear

author: king.oslo
author_rank: Frequent Contributor
timestamp: June 14, 2013, 12:10:11 pm
content: Hello there,I've got a XHR-150-7 150V 7AMP PSU. Recently I noticed some serious 3Vpp switching noise on the output. Think I will pop it open in a few days to check for problems. What is the common corporate causing problems like these?Thanks.Kind regards,Marius

author: Paul Price
author_rank: Super Contributor
timestamp: June 14, 2013, 12:50:33 pm
content: Large valued electrolytic capacitors (directly at the output? or HV mains post rectifier? have developed high ESR, outgassing or open. Look for the dead cap signature: any sign of the tops being domed shaped, bulging...should be perfectly flat in a healthy electrolytic.

author: David_AVD
author_rank: Super Contributor
timestamp: June 14, 2013, 10:04:35 pm
content: Also make sure that you're really measuring that noise on the output. Dave did a video recently where the signal shown on the scope was actually induced by another switch-mode power supply that was running nearby.
Fluke 5100 - what's the worth of that thing ?  - Page 1
Forum section: electronics / testgear

author: eevblogfan
author_rank: Frequent Contributor
timestamp: June 10, 2013, 04:32:18 pm
content: heyIn the cal lab we have one old fluke 5100 and it says "NOT WORKING" , I am pretty damm sure that either stupide fuse or bad caps internallyI need to know if that something worth playing with or notas far as I can see I won't be able to calibrate my HP34401 since that calibrator goes onlt to 5.5 digit res ,I may be able to buy that for 120$ or soI think of buying LTZ1000A and put it inside and send it for adjastment - Wonder how much do they charge for fully adjustment , and if it has to be shipped , man that some weight to fright ...what is your opinion ?can you spot me the pros and cons of the device ?thank you in advance !

author: edavid
author_rank: Super Contributor
timestamp: June 12, 2013, 06:19:05 pm
content: It's a great calibrator, and since it's so heavy, it is a big advantage that you can just take it home. If you can fix it, you probably won't need to adjust it, since they are quite stable.The bad part is that it may be hard to fix, because of the weight, and the complex/confusing circuit.I really doubt you could make any improvement on the existing reference.
about UNI-T UTD2025CL scope. - Page 1
Forum section: electronics / testgear

author: CHexclaim
author_rank: Regular Contributor
timestamp: June 12, 2013, 02:12:02 am
content: Hello everyone.I have the chance to buy a brand new UNI-T UTD2025CL scope at a really attractive price. Does anyone have any opinion, bad or good, that can help me decide if I buy it?Thank you very much, Charlie.

author: Hydrawerk
author_rank: Super Contributor
timestamp: June 12, 2013, 02:43:25 am
content: Really a low end scope.

author: CHexclaim
author_rank: Regular Contributor
timestamp: June 12, 2013, 03:02:04 am
content: Thank you Hydrawerk for your comment. Yes, I know about the category of this scope, but I do not have many options around. Do you know if it is a fairly new design or is it based in an old architecture?On the other hand I have a good price in the TBS 1000 series Tektronik scopes. I know that for the same price in the US there are many other options, but do you believe if one of these Tek scopes is a bad option?

author: valentinc
author_rank: Regular Contributor
timestamp: June 12, 2013, 02:59:33 pm
content: In my opinion, the TBS1000 series from Tektronix (because they are expensive and offer only 2.5Kpts of sample memory...) don't worth... There are a lot of situations (including bursts of digital data, complex analog signals (like video), modulated signals) where 2.5 Kpoints are not enough to reproduce the waveform...The UNI-T is probably the same as the Rigol DS1052, Siglent and ohter brands that share the same hardware... A good scope for the money... anyway...

author: Hydrawerk
author_rank: Super Contributor
timestamp: June 12, 2013, 03:13:46 pm
content: TBS1000 is suitable only for school use, or for someone who is used to TDS1000 or TDS2000. Definitely not a bang per buck, the scope is apparently obsolete.
Automated voltage rail monitoring - Page 1
Forum section: electronics / testgear

author: Russ.Dill@gmail.com
author_rank: Contributor
timestamp: June 11, 2013, 07:51:08 pm
content: I get a piece of test equipment that will allow me to monitor several voltage rails as part of an automated test. I just need to measure DC levels. I don't care if it's USB, serial, network, or other. Multiple channels would be nice, but if it's only one channel, I can buy multiple.I see stuff like the USBee DX, but it's got way more features than I need and the cost is way too high, especially when you need more than 2 channels:http://www.usbee.com/dx.htmlAny tips?

author: PedroDaGr8
author_rank: Super Contributor
timestamp: June 11, 2013, 08:04:53 pm
content: Quote from: Russ.Dill@gmail.com on June 11, 2013, 07:51:08 pmThat is QUITE pricey for what it is IMHO. I am not size is an issue but there are a variety of scanning DMMs out there. You don't mention, do you have a required precision or accuracy, minimum number of channels, voltage range?

author: Rufus
author_rank: Super Contributor
timestamp: June 11, 2013, 08:06:29 pm
content: Quote from: Russ.Dill@gmail.com on June 11, 2013, 07:51:08 pmhttp://www.mccdaq.com/Will sell you USB data acquisition modules starting at $99 for 8 single ended 12 bit channels.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: June 11, 2013, 08:16:16 pm
content: Quote from: Rufus on June 11, 2013, 08:06:29 pmThat looks quite good and likely would fit pretty well with the OP's requirements. Though I see no mentions of accuracy of the readings.If he needs something a bit more high powered there are always the Agilent 34790A data acquisition systems. They can do more than just DC monitoring and are typically $500-900 on ebay, but can monitor a high number of channels and has 22bit (6.5 digit) and 0.004% accuracy.

author: Russ.Dill@gmail.com
author_rank: Contributor
timestamp: June 11, 2013, 08:35:19 pm
content: Quote from: PedroDaGr8 on June 11, 2013, 08:04:53 pm4 digits would be fine, accuracy really only needs to be around 10mV, voltage range +/-10V. I can always add more devices to get more channels.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: June 11, 2013, 08:46:57 pm
content: If you don't mind one that is a bit old, check out the Keithley 199 DMM (with the Option 1992 multiplex interface). It will give you up to 8 channels, controllable via GPIP.

author: Russ.Dill@gmail.com
author_rank: Contributor
timestamp: June 11, 2013, 08:48:16 pm
content: Quote from: Rufus on June 11, 2013, 08:06:29 pmThey have an open source API that uses libusb, nice. It's .net/mono but really that's just a personal prejudice and not a technical one. I'll give it a go
siglent 100mhz - Page 1
Forum section: electronics / testgear

author: alex77
author_rank: Contributor
timestamp: June 08, 2013, 06:30:58 pm
content: hello,I'm new in this forum and certainly no expert in oscilloscopes.I am a computer technician and I bought my first oscilloscope, a siglent 1102cnl (100mhz), a few months ago mainly for troubleshooting computer motherboards. I was surprised when by chance I realized that it could measure waveforms of nearly 170mhz (I still don't know its limits). the waveforms look very stable and the frequency shown is ok.Is this kind of thing usual? should I buy a pair of 200mhz probes in order to try to get more from it?

author: Skimask
author_rank: Super Contributor
timestamp: June 08, 2013, 07:01:58 pm
content: 100Mhz 'scope doesn't mean it stops dead at 100Mhz and won't display a 101Mhz signal. It means generally that the analog input bandwidth is 100Mhz. Once you get above that range, the quality of the displayed signal might suffer, might show the signal as a lower amplitude than it actually is, etc.WIKI it...

author: rf-loop
author_rank: Super Contributor
timestamp: June 08, 2013, 07:10:42 pm
content: Quote from: alex77 on June 08, 2013, 06:30:58 pmOf course it can. It can trig and show over 400MHz.But of course level drops lot of.-3dB point is roughly around 150MHz (without probe)-6dB point is roughly around 200MHz (without probe)(measured with 50ohm external terminator what typically attenuate too much higher frequencies due to mismatch becouse scope input + 50ohm terminator is not 50ohm impedance specially with higher frequencies.)(with probe it is much more complicated and this is common thing, not Siglent thing. )This is SDS1102CML frequency response. CNL model have same freq response, but of course individual scopes may have small differencies. Only markable difference is memory.Here more.

author: alex77
author_rank: Contributor
timestamp: June 09, 2013, 01:15:39 pm
content: thanks a lot for your replies, I've learned a lot.
Lutron  LCR-9183 - Page 1
Forum section: electronics / testgear

author: akanowitz
author_rank: Contributor
timestamp: June 13, 2013, 06:22:03 am
content: Hi everyone,I am in the market looking at the above unit. All I need is to be able to test a cap and see if it is history. Unfortunately I have not seen too much info about these. I tried to contact ESR Blue manufacturers and to date still do not have response. Can anyone advise something that is simple and reliable to use.thanksAlan
Screenshot via USB from a InfiniiVision 2000 / 3000 x - Page 1
Forum section: electronics / testgear

author: Bob S
author_rank: Contributor
timestamp: June 08, 2013, 01:56:16 am
content: Hi all,Just starting with this scope and wondering if / how you can get a screenshot of the scopes display onto your PC using USB.The optional LAN module supports this (and more). The mobile link software can do it but is requires several steps. Am I missing something?thanks

author: Hydrawerk
author_rank: Super Contributor
timestamp: June 08, 2013, 02:19:27 am
content: https://www.eevblog.com/forum/reviews/my-new-toy-%29-agilent-dsox2002a-sex-on-a-stick!/msg229341/#msg229341
What would you pay for an Agilent MSO7104B? - Page 1
Forum section: electronics / testgear

author: kiss_eng
author_rank: Newbie
timestamp: June 06, 2013, 10:30:07 pm
content: Long story short I just purchased an MSO7104b, at a decent price, and am trying not to have buyer's remorse. While I could get away with using a slower scope, I like seeing square waves instead of sign waves on high speed signals. So, what would you pay for an MSO7104b, or what would you buy instead if you wouldn't. (Thanks for the help, and sorry for the bitching)

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 06, 2013, 10:32:13 pm
content: Soothe that remorse by loading it up with trial licenses and setting the clock back. You now got even better value for money!

author: ben_r_
author_rank: Frequent Contributor
timestamp: June 07, 2013, 02:00:45 am
content: Its much more important that YOU feel what YOU paid was a good deal.Typically I use completed listings searches on eBay to kinda gauge what a good deal is. For the MSO7104b I would guess something like $9-10K would be a good deal depending on condition and warranty.

author: kiss_eng
author_rank: Newbie
timestamp: June 08, 2013, 12:14:05 am
content: Thanks for the help guys, I'm feeling much better now(The wife's the one that really got on me about it. Wasn't really concerned about the purchase until she was concerned. So it goes.)
Metrix MX57Ex Digital Multimeter - Page 1
Forum section: electronics / testgear

author: nukie
author_rank: Frequent Contributor
timestamp: June 07, 2013, 04:12:09 am
content: Can someone please clarify why this multimeter is so expensive? It doesn't print money does it??http://www.instrumart.com/products/34976/aemc-mx-57ex-multimeterhttp://www.cuthbertsonlaird.co.uk/Detail.asp?ProdID=330

author: don.r
author_rank: Frequent Contributor
timestamp: June 07, 2013, 04:18:30 am
content: Maybe because its ATEX-certified?

author: millerb
author_rank: Regular Contributor
timestamp: June 07, 2013, 04:19:33 am
content: Its main selling point is that you can use it in potentially explosive atmospheres.

author: Lightages
author_rank: Unknown
timestamp: June 07, 2013, 04:39:54 am
content: The same reason this one costs so much:http://www.testequipmentdepot.com/fluke/dmm/28iiex.htm

author: Rick Law
author_rank: Super Contributor
timestamp: June 07, 2013, 04:07:51 pm
content: Quote from: nukie on June 07, 2013, 04:12:09 amI learned that some sellers (eBay, perhaps others) would put in a very very high price (temporarily) so as no one would order while they are out of stock, and change the price back down to earth when they get stock again. They do so to save the trouble of deleting the post and re-post later. They also get to keep the stats (xxx sold).I suppose the added logic too is, if I am out of stock of this $60 DMM, and if some one say paid me $1,000 for one, I sure would take the trouble to get one for him/her somehow for that kind of profit.Rick

author: rdl
author_rank: Super Contributor
timestamp: June 07, 2013, 04:38:41 pm
content: I worked in industrial coatings (paint) for 25 years. We would call this type of equipment "explosion proof". This requirement always adds a lot of cost.http://en.wikipedia.org/wiki/Electrical_equipment_in_hazardous_areas
Tenma 72-410A schematic and calibration info. - Page 1
Forum section: electronics / testgear

author: Unknown
author_rank: Unknown
timestamp: June 07, 2013, 01:02:39 pm
content: I'm not asking for it, I have it. I asked MCM for the information yesterday, and this morning, they came through! So I'll share here, as this info seems to be rather hard to come by. Enjoy. (multiple posts as these files are too large when taken at once)

author: Unknown
author_rank: Unknown
timestamp: June 07, 2013, 01:03:20 pm
content: Some more...

author: Unknown
author_rank: Unknown
timestamp: June 07, 2013, 01:04:02 pm
content: And the rest.
Hantek 4032L - Opinions please  - Page 1
Forum section: electronics / testgear

author: Fraser
author_rank: Super Contributor
timestamp: April 21, 2013, 12:06:31 pm
content: I already own a Link Instruments MSO-19 logic analyzer (http://www.linkinstruments.com/mso19.htm) and I am considering the purchase of a newer model. I do not use logic analysers a great deal in my daily work but the repair of some embeded boards recently made me think of an increased number of channels being useful.I am aware that Hantek does not always have the best software but the unit does appear half decent from the user manaul.Does anyone have an opinion on the device or a better product for similar money (GBP150)Hantek page is here:http://www.hantek.com/english/produce.asp?classid=31http://www.hantek.com/english/produce_list.asp?unid=67Manual is here:http://www.hantek.com/Product/HT4032/4032_Manual.PDFRegardsFraser

author: Yaksaredabomb
author_rank: Regular Contributor
timestamp: June 05, 2013, 09:09:59 pm
content: That's funny, I saw your post here where you mentioned the Hantek 4032L:Need help selecting a logic analyzerThen this thread was the 4th link down when I searched Google for "Hantek 4032L". So I guess no one gave you any opinions but you went for it anyways, and find it tolerable?Edit June 6th: My display name has recently changed from "jneumann" to "Yaksaredabomb"

author: Fraser
author_rank: Super Contributor
timestamp: June 06, 2013, 09:01:09 am
content: Hi,Yes I looked at what was available on the market and read the comments regarding the Hantek 5034 and decided the 4032 would suit my needs. I have only used it briefly a I am buried on other work but it appears to do what I need. I am looking a an MC68000 based embedded computer with a problem during boot causing a HALT on the system. The 32 channels and decent sampling rate are perfect for the requirement. The units GBP140 price seems very fair for what you receive, and compared to the several thousand pounds that the embedded computer is worth, its well worth the investment. I took some pictures of the units internal parts and it looks to be a decent design.I certainly don't have problems with the Hantek software but then I am not an advanced user of logic analysers !My other posting is here:https://www.eevblog.com/forum/testgear/hantek-ht4032l-logic-analyser/

author: Yaksaredabomb
author_rank: Regular Contributor
timestamp: June 06, 2013, 11:49:53 am
content: Thanks for the update, impressions, and link! I was just curious (for now), but if I was in the market it would be really helpful.Edit June 6th: My display name has recently changed from "jneumann" to "Yaksaredabomb"
oscilloscope for 300-400 EUR - Page 1
Forum section: electronics / testgear

author: Elandril
author_rank: Contributor
timestamp: June 07, 2013, 09:48:03 pm
content: After a few years of having no time due to house building, I'm about to reenter my old electronics hobbyand so I'd like to finally upgrade my "lab" with a digital oscilloscope.I'm looking for a digital oscilloscope in the 300-400 EUR price range (constraint in place by SWMBO), but feel a bit overwhelmed by all the (rebadged) products out there: Rigol 1052E, Owon, Atten, Uni-T, PeakTech,...So are there obvious choices out there (or any models to avoid)? I'm grateful for any comment and recommendation!

author: madires
author_rank: Super Contributor
timestamp: June 07, 2013, 09:54:18 pm
content: I'd go for the Rigol DS1052E (€280) or the DS1102E (100 MHz, €390).
Agilent U8001A very loud hum noise - Page 1
Forum section: electronics / testgear

author: jbbeck
author_rank: Newbie
timestamp: June 04, 2013, 06:23:00 pm
content: Hey...I just bought a Agilent U8001A, but when I take it above 1 - 1.3 A it starts to make a loud sound, like a old 230/400V AC relay (a very loud hum), should it do that? it is very annoying. I would like to be sure that it is not just me, before i send it back, because i don't want to spend money on returning it, if it is just how it is.

author: saturation
author_rank: Super Contributor
timestamp: June 04, 2013, 08:48:17 pm
content: Check filter caps. Hum are often caused by resonance of components inside the PSU or transformer core by magnetorestriction, but this is often faint and regardless of load. If it varies with load, it suggests a filter cap is failing, allowing less regulated voltage through that is adding to the resonance.If it doesn't vary with load, you can use dampening techniques, such as putting rubber washers underneath the transformer mounting. Search google under "transformer hum".
Fluke 2625A - "error 6" - "instrument configuration corrupted" - Page 1
Forum section: electronics / testgear

author: uoficowboy
author_rank: Regular Contributor
timestamp: May 29, 2013, 12:35:44 am
content: Hi - I am hoping to resurrect a Fluke 2626A. When powered up, it occasionally throws an error 6. According to the manual, this means "instrument configuration corrupted".Does anybody know what could cause this and how to fix it?Thanks!!edit: setting the time clears this error and gets things working, but after a couple power cycles it seems to come back. I wonder if there is a toasty battery in there somewhere...

author: uoficowboy
author_rank: Regular Contributor
timestamp: June 04, 2013, 03:42:54 pm
content: The device continues to be rather forgetful when power cycled. Definitely a bad battery. However, I see no batteries inside the device. I did, however, find an ST MK48T08B-15. It is a 28 DIP with a sort of lithium battery backpack permanently attached to it. I found some replacements on Ebay here:http://www.ebay.com/itm/321102182543hopefully the battery is still good in those...If they don't work, I found a thread online saying that you can dremel off the top of the battery pack and get at the wires going to the battery. So there's a backup plan.
Standard / advanced Audio measure with oscilloscope - Page 1
Forum section: electronics / testgear

author: luca1000
author_rank: Regular Contributor
timestamp: June 07, 2013, 06:58:46 pm
content: Hi,Some years ago someone told me about particular techniques to show, with only a standard analog oscilloscope (30 Mhz), the distorsion, noise , dynamic range, frequency response, etc..This without use a specific equipment like specturm analizer , distorsion meter , etc..At the end, he confirm me that these technique are not applicable with a digital oscilloscope but only with analogue scope.Now I don't remember exactly what are these technique.Someone can suggest me some standard / advanced way to show the distortion, noise and other usuful informations with an oscilloscope ?Any pdf / handbooks are appreciated.

author: G7PSK
author_rank: Super Contributor
timestamp: June 08, 2013, 05:59:26 pm
content: Here's something from a 1960's book on using an oscilloscope by D.W.Easterling. This is pre DSO but I am sure that you could use one for the same purpose.
Tenma 72-410A teardown - Page 1
Forum section: electronics / testgear

author: Unknown
author_rank: Unknown
timestamp: June 03, 2013, 04:18:52 pm
content: Dave inspired me to start a video blog series I call the "I kinda sorta know what I'm doing" series. episode 1, where I battle bad lighting and pushing the wrong button, is a Tenma teardown. Thought you all might be interested.I don't have the Australian accent, hope you can forgive me.I figure as I figure it out, the lighting will get better, etc.Two things I didn't mention: The solder quality is HORRIBLE (the through hole plated joints aren't done all the way through) and the switches are interesting in that there's no logic behind how they work. All of the LEDs, etc, are done from the switches themselves. It's truly a very simple circuit.
*HELP* YH-853D Reworking Station 3 in 1 Power Failure, and Soldering Iron Prob - Page 1
Forum section: electronics / testgear

author: robthegeek
author_rank: Newbie
timestamp: May 28, 2013, 02:02:15 pm
content: Hello there,I have a cheapy China made YH-853D Reworking Station 3 in 1. The hot air gun works perfect. Still gives an, supposedly, accurate temp on the display.However, the DC power on it went out one day. Now when that is on it just beeps for over current. The soldering iron still gets hot but no temp control. The display shows a temp but it is just on full blast at the lowest setting 200.The insides look very basic. Transformer, power distribution and then the controller for the display.This guy does a basic review and cracks the case.Any help on the subject would be appreciated. I'm not an engineer just a hobbyist but learning.ThanksRobtheGeek

author: Tube_Dude
author_rank: Regular Contributor
timestamp: June 03, 2013, 02:11:36 pm
content: The guy in the vídeo, call the TO3 power supply pass transístor, thermal cut-off...
Should i buy Fluke 87v RMS for 270$? - Page 1
Forum section: electronics / testgear

author: nardev
author_rank: Unknown
timestamp: June 04, 2013, 05:42:51 am
content: There is my neighbour who worked in Iraq and had 3 Fluke's "87v RMS". One which is left was not used at all, it was like backup. Now he is selling for 270.Is it a good price? Should i buy it?

author: Unknown
author_rank: Unknown
timestamp: June 04, 2013, 06:48:47 am
content: http://www.ebay.com/sch/sis.html?_kw=Fluke+87+True+RMS+Multimeter+Meter+DVM+EXCELLENT+LN

author: nardev
author_rank: Unknown
timestamp: June 04, 2013, 07:34:06 am
content: Quote from: JuanPC on June 04, 2013, 06:48:47 amYea.. but new one comes at about the same or even more...

author: Dave
author_rank: Super Contributor
timestamp: June 04, 2013, 09:56:56 am
content: When buying from eBay, you will need to pay postage and customs as well. I really doubt you will be able to find an 87V for less in Bosnia. Try to knock the price down a bit and go for it.

author: BravoV
author_rank: Super Contributor
timestamp: June 04, 2013, 10:00:31 am
content: Have you ever thought of the luxury of physically inspecting the dmm your self before buying, is that worth something here ?Not to scare you though, imagine you have a really bad luck that the DMM is crushed during shipping, or worst the seller is a scammer by selling you a dead DMM ? Unlikely though, but still could happen.Think again, how much is this worth of buying an used DMM online versus this traditional method ?

author: nardev
author_rank: Unknown
timestamp: June 04, 2013, 01:29:56 pm
content: Thnx, at first i thought i could be cheaper somewhere else.Quote from: Dave on June 04, 2013, 09:56:56 amSlovenac, bas mi je drago da vidim nekoga sa Balkana, pozdrav.

author: Dave
author_rank: Super Contributor
timestamp: June 04, 2013, 02:39:18 pm
content: Quote from: BravoV on June 04, 2013, 10:00:31 amNot to mention the opportunity to negotiate the price. There is no negotiation like face to face. It does take some practice, but it's really exciting once you figure it out. HAM radio fairs are a great place to do so.Quote from: BravoV on June 04, 2013, 10:00:31 amNot long ago I had a terrible experience with an eBay seller from UK. I won the auction for a HP 34401A and the moron packed it in a very thin layer of bubblewrap and scrap pieces of cardboard. Needless to say, the meter was trash upon arrival. The power switch would just stay inside when pushed, no click back. I had to pay the return postage (over 20€) and I wasted a lot of time trying to communicate with the seller.It's really a thing of luck, sometimes you come across a great seller, sometimes you run into a moron.Quote from: nardev on June 04, 2013, 01:29:56 pmPozdrav, prijatelj!
Rigol 1052E vs old Fluke 124 - Page 1
Forum section: electronics / testgear

author: JuergenB52
author_rank: Contributor
timestamp: June 02, 2013, 08:00:36 pm
content: I have a realy old Fuke 124 for HiFi repairs and for trend plots, sometimes i do check serial connections and jtag signal.i do repair some TFT displays, mostly power supply and tube amps.The display is hardly readable (backlight is not good) and Battery is not good, lasts for 2-3 hours.I use it mostly on my workbench.Will a new Rigol 1052E be a good and cheap choice?Any recommendation?thanks

author: Bored@Work
author_rank: Super Contributor
timestamp: June 02, 2013, 08:13:34 pm
content: Cheap yes, good mostly. It will not be isolated from ground, as opposite to your ScopeMeter. It will not be as small as your ScopeMeter. It will not be as safe as your ScopeMeter. It will not run from battery. Everything else should be better.

author: robrenz
author_rank: Super Contributor
timestamp: June 02, 2013, 08:22:05 pm
content: If you used it much you will sorely miss Trend Plot. Probably my favorite feature of my 8846A.

author: zaoka
author_rank: Frequent Contributor
timestamp: June 03, 2013, 01:34:53 am
content: What do you think about new Siglent handheld?http://www.ebay.com/itm/SIGLENT-SHS806-Handheld-Oscilloscope-1-Ghz-Sampling-Rate-SHS806-/380574099745?pt=BI_Oscilloscopes&hash=item589bfbe921It has trendplot as well.I am thinking to buy one.

author: robrenz
author_rank: Super Contributor
timestamp: June 03, 2013, 01:55:13 am
content: Save yourself some moneyheresame supplier. I have to look at the manual to see what their trend plot is like.
Question about Scopes with CRT's (Solved) - Page 1
Forum section: electronics / testgear

author: slim
author_rank: Contributor
timestamp: June 02, 2013, 01:47:46 pm
content: Hello all,I am looking to get back into the hobby and am looking to buy my first used scope.I have been looking at the tek 2467 line, Particularly ones with the #6 option and have a Q about what I am seeing out there.Some of the scopes have a red boarder on the display, Is this indicative of a failing CRT or other problem?Thanks in advance

author: BravoV
author_rank: Super Contributor
timestamp: June 02, 2013, 01:51:05 pm
content: Quote from: slim on June 02, 2013, 01:47:46 pmNo, that is the back light for the graticule with the adjustable brightness, and can be turned on and off.Edit :For example here my 2465B (should be similar to 2467) with red backlight turned off. There is a knob with label "SCALE ILLUM" at the bottom, thats the knob for the red back light.This with the red back light turned on. If you watch closely at the bottom, there are 3 brighter spots where the light originated by the incandescence lamps located at the bottom of the screen.

author: slim
author_rank: Contributor
timestamp: June 02, 2013, 02:42:18 pm
content: Thank you very much BravoV
HP 6205C not quite zero - Page 1
Forum section: electronics / testgear

author: don.r
author_rank: Frequent Contributor
timestamp: May 30, 2013, 06:29:53 pm
content: I have a 6205C that won't quite reach 0v when wound down (reads about +20mv). The voltage control pot reads 0 ohms. The service manual says to shunt R6 or R8 with an appropriate value resistor to achieve 0V (after experimentation with a decade box) but I thought about replacing them with a series 330K and 470K and two 100K pots so that adjustments could be made in the future. Problems?BTW, for some reason R6 is a beefy 1/2 watter, not sure why, maybe temp stability?

author: don.r
author_rank: Frequent Contributor
timestamp: June 03, 2013, 01:36:36 am
content: After poking R6 a little I noticed the voltage changed. I reflowed the joints and now its only a mv or 2 out so good enough for me. I guess the joint cracked maybe due to transport.
Is Agilent 54615B scope good for beginer? - Page 1
Forum section: electronics / testgear

author: Magnifito
author_rank: Newbie
timestamp: June 05, 2013, 08:38:35 pm
content: Hi,I can buy Agilent 54615B for about 130$ shipped. However it is sold as untested with a picture showing signal which as I presume is noise (http://zdroj.org/allegro/oscyloskop/oscyloskop_agilent_54615b_1.jpg).Should I buy it? Would it be useful for me in the future when I will buy 1000+$ scope?Thanks in advance for advice!

author: dfmischler
author_rank: Frequent Contributor
timestamp: June 06, 2013, 12:01:10 am
content: It sounds like a great deal if it works. Not so much if it doesn't. Can you return it if it doesn't work? Can you get the seller to test it?

author: Hydrawerk
author_rank: Super Contributor
timestamp: June 06, 2013, 01:26:50 am
content: The record length is poor, but anyway this series 54600 was once quite popular.http://cp.literature.agilent.com/litweb/pdf/54615-97019.pdfAt least it has 1GSa/s per each channel. Well, it's a nice old scope. The first scopes of 54600 series were made in early 1990's.
Tektronix 2225 - Page 1
Forum section: electronics / testgear

author: Anne
author_rank: Newbie
timestamp: May 31, 2013, 12:59:58 pm
content: Dave, thanks for the great video's on the Tektronix 2225 scope!!-Tektronix 2225 Analog Oscilloscope - EEVblog #196-Tektronix 2225 Oscilloscope Teardown and Calibration - EEVblog #208By any chance, yesterday I came across one! With your excitement in mind I picked it up!Especially the following side note convinced me at the time :)-Tektronix 2225 Oscilloscope Teardown and Calibration - EEVblog #208 (14 min 21 sec)It works like a charm and seems to be calibrated reasonably well.Thanks for pointing out this scope!Best wishes from the Netherlands!Anne

author: don.r
author_rank: Frequent Contributor
timestamp: May 31, 2013, 02:48:16 pm
content: Great scope. Excellent for looking for sub 1mv noise. Love mine!
Rigol DG4000 series counter - Page 1
Forum section: electronics / testgear

author: jpb
author_rank: Super Contributor
timestamp: May 30, 2013, 03:46:01 pm
content: I've a feeling this has already been covered but I couldn't find it by searching.I was just looking at the specs for the Rigol DG4162 and I see the counter is specced at 6 digits/sec (gate time of 1sec) but it shows 12 digits all the time!?The default gate time is only 1.3ms which presumably means only the first three digits are meaningful?To get 12 digits worth you'd need to set a gate of 11.5 days? (Or is my maths wrong?)I remember on another thread someone saying that they got 9.999 999 ... for a Rubidian 10MHz source but this apparent accuracy is presumablya fortuitous combination of it using binary and counting a whole number that is pretty close.

author: AndyC_772
author_rank: Super Contributor
timestamp: May 30, 2013, 04:00:23 pm
content: You can set the gate time - but if you're looking for accurate frequency measurements I couldn't recommend the DG4xxx family. There are definitely some rounding / quantisation issues with the displayed frequency, it's not nearly as precise as it could or should be.

author: EV
author_rank: Frequent Contributor
timestamp: May 30, 2013, 05:13:04 pm
content: I have also wondered this earlier and tested it again. The counter gives 7 correct digits with Rubidium standard as external clock and 10 s gate time. The accuracy is quite the same with internal clock. So why are there 4..5 irrelevant numbers?

author: jpb
author_rank: Super Contributor
timestamp: May 30, 2013, 05:22:19 pm
content: I'm also taken aback by the number of digits. I would guess it is similar to scope counters which are typically 6 digits but only show 6 digits. It seems to be a marketing rather than engineering addition. I can imagine one of the Rigol design engineers suggested that they could easily add a simple six digit counter, the marketing department then looked around and saw top quality counters had 12 digits and it all morphed from there.In a similar vein, last time I was in Tokyo I noticed in the taxi the dimensions, such as height, on some official plaque were given to the nearest mm!

author: KedasProbe
author_rank: Frequent Contributor
timestamp: May 31, 2013, 11:09:11 am
content: The Standard Deviation shown in the statistics gives you a clear view of the accuracy.So I don't mind more digits.
Beckman Circuitmate FG2 service manual - Page 1
Forum section: electronics / testgear

author: heathkitman
author_rank: Contributor
timestamp: May 28, 2013, 08:06:58 pm
content: I am looking for the service manual for the Beckman Circuitmate FG2 2Mhz Function Generator. Something that would cover the calibration procedure .Thanks
Leader 1041 manuals. - Page 1
Forum section: electronics / testgear

author: G7PSK
author_rank: Super Contributor
timestamp: May 28, 2013, 03:33:12 pm
content: I have just got a Leader 1041 oscilloscope from E bay and am looking for any manuals for it, so far my search on the web has come up zilch for this model, does ant one have a copy they could let me have as a pdf or even have a hard copy they want to sell. i have not yet received the scope so know very little about it just that it's a Leader 1041 40mhz and has a trace.