hybridfree/eevblog-posts huggingface dataset:
Help me about oscilloscope ? - Page 1
Forum section: electronics / testgear

author: Nhan95
author_rank: Contributor
timestamp: April 09, 2016, 02:17:02 pm
content: I want to observe the signal on resistor and capacitor in this circuit by oscilloscope. But if I connect the probe of channel 1 and 2 like the picture, the inductor will be short circuit. How do I do in this case ? Help me. thank you so muchAssume we don't swap the component.

author: nctnico
author_rank: Super Contributor
timestamp: April 09, 2016, 02:23:41 pm
content: The grounds of the probes are connected together and to earth (the ground wire in the mains lead) on 99.9% of the oscilloscopes so there is your problem.

author: mauroh
author_rank: Frequent Contributor
timestamp: April 09, 2016, 02:36:52 pm
content: Swap C1 and L1, the circuit will not change.Leave CH1 as is and move up CH2 across C1Select Invert CH2 on the oscilloscopeNow you have the ground connected toghether and the signal of R1 and C1 on the scope without short circuitsIf you have a 4ch oscilloscope you can use 3 channels and the math function without swapping C1 and L1Mauro

author: Brumby
author_rank: Unknown
timestamp: April 09, 2016, 02:39:33 pm
content: I was going to suggest something - but I like this idea much better...Quote from: mauroh on April 09, 2016, 02:36:52 pm

author: alsetalokin4017
author_rank: Super Contributor
timestamp: April 09, 2016, 10:27:45 pm
content: Don't forget that in the "real world" the BNC shields of the Function Generator's output jacks are also likely to be connected to the Mains Ground and hence also connected to the Scope Probe grounds through the mains power cords.

author: mauroh
author_rank: Frequent Contributor
timestamp: April 11, 2016, 09:38:18 am
content: Good point alsetalokin4017, I think the easiest way is to rearange again the circuit moving R1 close to C1.Now CH1 will see the wave form across R1 and using the marh function, the difference CH2-CH1 will be the signal on C1.Don't know if Nhan95 is still interested in this....Mauro
Hartmann&Braun H&B Elavi 2 - Page 1
Forum section: electronics / testgear

author: Thilo78
author_rank: Regular Contributor
timestamp: April 10, 2016, 01:18:47 pm
content: At saturday's hamfest/boot sale I got a few items for my lab.This is number two:A H&B Elavi 2 multimeter, unknown vintage.If anyone knows, which year they were produced, please let me know.Really nice unit, also near mint condition.This one has a brown bakelite (?) case, which appears unusual, as I only know them with black cases.Tried it out yesterday. Works like a charm
Fluke 8400 and 8842A DMM - Page 1
Forum section: electronics / testgear

author: avvidclif
author_rank: Regular Contributor
timestamp: April 09, 2016, 11:28:45 pm
content: A friend has one of each for sale, cheap, less than $50 ea. All he knows is they turn on. Any thoughts on either. It would be a bench unit. Currently using a HP 3478A and a Fluke 8050A. The 8050A is primarily for the diode test function and HV so it wouldn't go away.

author: edavid
author_rank: Super Contributor
timestamp: April 10, 2016, 02:20:57 am
content: The 8400A is very old/large/heavy, but a nice meter if you like Nixies. AC and ohms are option boards, so may not be included. I'd say $50 is on the high side.The 8842A is similar to your HP 3478A, but has a nice readable VFD in place of the 3478A's crappy LCD. $50 is a great deal if it's working.

author: avvidclif
author_rank: Regular Contributor
timestamp: April 10, 2016, 02:45:08 am
content: Thanks that's what I was looking for.

author: xwarp
author_rank: Frequent Contributor
timestamp: April 11, 2016, 07:35:18 am
content: If the display on the 8842a is still somewhat bright and it passes all the self tests, that's not a bad price.I have an 8842a that I paid $7 for that is a nice unit with a bright VFD.

author: dr.diesel
author_rank: Super Contributor
timestamp: April 11, 2016, 07:41:09 am
content: The 8842A also has the LTFLU voltage reference!

author: avvidclif
author_rank: Regular Contributor
timestamp: April 12, 2016, 09:24:39 pm
content: He had 4. One had a 1/2 bright display. All 4 checked as operational. I picked the prettiest one that had intact calibration stickers.
Some vintage function generator pics - Page 1
Forum section: electronics / testgear

author: kendalll
author_rank: Contributor
timestamp: April 10, 2016, 06:52:14 am
content: I was at my high school's alumni weekend and they had the physics lab open. One of the teachers was there and was saying this stuff was up on that top shelf when he left 30 years ago.

author: DTJ
author_rank: Super Contributor
timestamp: April 10, 2016, 08:25:54 am
content: I like the dead fly under the front of the Heathkit, he's probably been there a while too.There's a few memories in those pics.
[SOLVED] Rigol DS1054Z Loses Settings on Reboot - Page 1
Forum section: electronics / testgear

author: jpanhalt
author_rank: Super Contributor
timestamp: April 06, 2016, 10:01:39 am
content: 1) For the first 4 months, whenever I turned the scope off it automatically saved all settings. Yesterday, it stopped doing that and reboots as almost a new scope would with only channel 1 active and in the center of the screen. All vertical settings and horizontal settings from the previous session are lost. I searched on the Internet and couldn't find a solution. Also tried a "save" but that didn't help.2) This problem resolved, but was bizarre. In the "coarse" settings mode for vertical sensitivity, the sequence for all channels was 1,2,5,10 V. Three days ago, that sequence changed for channel one only and was 1,2,4,10 V. Of course using the fine control I could set the voltage to 5 V. After a few reboots over 2 days, this problem disappeared, but then the problem described in #1 started. That behavior made me wonder whether they might be related, such as a problem in flash memory.Thank you. John

author: Blaffetuur
author_rank: Regular Contributor
timestamp: April 06, 2016, 10:29:22 am
content: Do you have the power up set to default or last ?https://youtu.be/W2qdtQkBKhc?t=11m8s

author: jpanhalt
author_rank: Super Contributor
timestamp: April 06, 2016, 10:52:35 am
content: Thank you.That solved the problem with #1. Don't know how it got set to default. Maybe while I was trying to solve problem #2. I can live with the second issue, should it ever recur. So far, my problems have all be "pilot error."There is a lot to learn on that scope. I do like the cursor options; although, I find the "Quick 1..5" not very helpful -- can't remember the sequence of my last five. I always just go to the menu and select what I want. The scope, however, remembers better than I do, and tells me it is already selected.One thing I would like to see is a chart with all of the menus and sub-menus. Jason (?) at Rigol said there are too many, but still, I believe it would be helpful versus pressing on various buttons to find them.John

author: alsetalokin4017
author_rank: Super Contributor
timestamp: April 07, 2016, 01:04:26 am
content: QuoteThat's very strange, and rather worrisome. Good that it has stopped doing that, but if it ever does it again, let's try to find out what other settings might be causing this behaviour.
ITech IT6302/ IT6322 and A/B and BK Precision 9129B Software question - Page 1
Forum section: electronics / testgear

author: mohala
author_rank: Newbie
timestamp: April 06, 2016, 07:28:02 pm
content: Hiya Guys,I have been looking around for a 3 way PSU with good data logging facilities via the computer and I came across BK first with their new 9129B, but later looking around find out the same model is also known as ITech IT300 series I think from memory the IT6302 is the same spec.My question here is that I had look at the software from BK and I really liked it but will cost me £510 ex VAT, which is quite expensive but the alternative is IT6302 or the better version IT6322A are half the price from China.I was wondering has any one got the IT6300's PSU and if you did get it from china did it come with software ready or is it only the LABview driver? Also, has anyone got the BK 9129B software working on the IT6300 PSU's?Mo
Budget scopes and intensity graded display - Page 1
Forum section: electronics / testgear

author: gardner
author_rank: Regular Contributor
timestamp: April 04, 2016, 10:47:04 pm
content: I am trying to choose between the Siglent SDS1102CML @ $440 and the Rigol DS1054Z @ $560. Overall I like the features of the Rigol, but the price I get here in Ontario is higher, even though it's the lower bandwidth model.Graduated display is something I really want though. I've seen Dave's video on the Rigol DS1104Z and he shows the intensity graded display for that, and the operation of the Rigol looks fine for my needs. There are many comments and threads covering the Siglent SDS1102CML, but I can't find any mention of the intensity graded display. The very useful oscilloscope spreadsheet indicates that this model has a 256-level grading. Anyone have any comments or screenshots or pointers to reviews etc that discuss the intensity graded display feature on the Siglent?Thanks.

author: nanofrog
author_rank: Super Contributor
timestamp: April 04, 2016, 10:54:31 pm
content: FWIW, the Rigol can be unlocked to 100MHz, double the memory (it's already on the board), and make the optional software features unlimited. Should help improve it's value.Search for riglol 1.03d, and you should easily find both the site and instructions (it's easy, and only takes a few minutes).

author: tautech
author_rank: Super Contributor
timestamp: April 05, 2016, 08:52:10 am
content: gardner, the SDS1102CML doesn't have an intensity graded display.Siglent's recently released SDS1102X model does.Threads of interest for more info:https://www.eevblog.com/forum/testgear/siglent-sds1000x-series-oscilloscopes/https://www.eevblog.com/forum/blog/eevblog-797-siglent-sds1000x-review/

author: gardner
author_rank: Regular Contributor
timestamp: April 05, 2016, 06:05:25 pm
content: Quote from: tautech on April 05, 2016, 08:52:10 amAh! Major mis-read of the scope list on my part. I see I was looking at the ...X line. Ooops. Thank you.
Tektronix THS720 frozen - Page 1
Forum section: electronics / testgear

author: mnow
author_rank: Newbie
timestamp: April 06, 2016, 07:22:51 am
content: Got a TEK THS720 that seems to turn on. It goes to a dim scope screenbut then no functions work. Possible corrupt firmware??

author: R_G_B_
author_rank: Frequent Contributor
timestamp: April 07, 2016, 06:50:10 am
content: Try turning up or reducing the contrast.It could be the display?Do you hear any clicks when it switches on?Try plugging in a probe and select auto on the the voltage range. Apply a signal with different voltages can you hear the relays start to click.Makes sure your wall wart or power supply is able to provide at least 1.2 amps of current other wise when switching on it will just give you a dim screen and switch off.R_G_B

author: mnow
author_rank: Newbie
timestamp: April 07, 2016, 07:42:37 am
content: After boot-up, the screen is dim in the scope mode and none of the buttons function.Also, there is no test signal on the scope cal point but only a 22v 60hz hum.Kind of looking like a bad main board at this point.What you think?
Hantek DSO4102C - Page 1
Forum section: electronics / testgear

author: glicos
author_rank: Regular Contributor
timestamp: February 07, 2016, 06:55:11 am
content: After a few weeks of waiting, my first Digital Oscilloscope arrived. Though i read a lot of negative reviews of Hantek products in this forum, i finally decided to give it a shot since i'm more on troubleshooting and repairing circuits than circuit designing. Anyway I'm not that experience in reviewing test equipment, but if you have any question regarding this scope, im glad to give answer to the best of my ability and understanding. Teardown??? Of course i WILL DO IT but not for now since i have a lot of things to do.Here's the image:For the details and specs:http://www.hantek.com/en/ProductDetail_3_4163.htmlA quick experiment in seting up a VI component tester utilizing its build in DDS Function Generator.This is it for now since may internet is too slow to upload more pictures. Will soon post pictures of the teardown..

author: PLATIJET
author_rank: Contributor
timestamp: March 19, 2016, 01:28:43 pm
content: So after 1 month what do you think, worth a buy?

author: Steps
author_rank: Contributor
timestamp: April 04, 2016, 02:52:36 pm
content: Hi! I am going to buy this. Or... Siglent may be. But signal generator is quite good for lab purposes, and chipo integrally:). But what about quality?

author: glicos
author_rank: Regular Contributor
timestamp: April 05, 2016, 01:19:41 am
content: So far it serves my purpose. But i observed some occasional hangups of the scope during acquisition (need reboot to recover from hangups). I now upgrade it to latest firmware and as of this time, i don't observed any hangups. The build in function and arbitrary generator are also ok, but if your into audio work and you need a low distortion signal generator..then this equipment is not suitable for you.I suggest get a Siglent and a dedicated Function GenHantek support is slow and very much limited..
Service manual request: Krohn-Hite 7500 Wideband Amplifier - Page 1
Forum section: electronics / testgear

author: jeremy
author_rank: Super Contributor
timestamp: April 12, 2016, 07:59:48 am
content: Hi all,It's in the titleMy google skills are failing me here, can anyone help me?More specifically, I'm interested in the schematic which is supposedly inside the service manual.
Tweezer test leads (NOT tweezer meters) - Page 1
Forum section: electronics / testgear

author: AdamHi
author_rank: Contributor
timestamp: March 31, 2016, 11:53:33 pm
content: Based on what i've seen around the web, I don't want to buy a cheap tweezer-meter (Smart Tweezer clone). I've also seen mixed reviews on inexpensive tweezer leads for DMMs. I saw that Probe Master makes some - and I tend to like their stuff - anybody tried their version? I'd be using them to confirm parts (R and C mostly), sometimes on boards.http://probemaster.com/dmm-multimeter-test-leads/tweezer-test-leads/--adam

author: AdamHi
author_rank: Contributor
timestamp: April 03, 2016, 03:00:28 am
content: Nothing heard . . . so i went ahead and ordered a set.In case it helps somebody in the future, I'll report back when i've tried them out.Features from the Probemaster site:Gold Tips & ConnectorsVoltage rating 250 VRMS@ 3 AMPSShielded RG174/U CableLength 5 ft.$19.90--adam

author: radhaz
author_rank: Regular Contributor
timestamp: April 03, 2016, 03:02:34 am
content: I agree about liking Probe Master stuff. Well made.

author: djQUAN
author_rank: Frequent Contributor
timestamp: April 03, 2016, 03:07:11 am
content: I made one a while back.http://www.quan-diy.com/projects/testjig/smdtweez.htm

author: nanofrog
author_rank: Super Contributor
timestamp: April 03, 2016, 04:18:59 am
content: FWIW, the vast majority of my DMM test leads are from Probemaster. I've been using their stuff for years and not had any problems thus far. And although I don't have that specific test lead (tweezers), I suspect you've made a good choice.I do look forward to you're reporting back though.

author: rx8pilot
author_rank: Super Contributor
timestamp: April 03, 2016, 06:05:02 am
content: Generally happy with Probe Master - but my tweezers are terrible. Never use them.

author: peter.mitchell
author_rank: Super Contributor
timestamp: April 03, 2016, 07:55:33 am
content: I got the probemaster tweezers after buying their other leads - the tweezers were rubbish. just as bad as $5 chinese junk, with better banana jacks.

author: nanofrog
author_rank: Super Contributor
timestamp: April 03, 2016, 12:31:33 pm
content: Quote from: rx8pilot on April 03, 2016, 06:05:02 amQuote from: peter.mitchell on April 03, 2016, 07:55:33 amUnexpected, but good to know if I ever decide to get a pair (I usually use pogo/spring loaded instead).djQUAN's link is giving me some ideas for a true Kelvin set(I'd like better than what came with my DER EE DE-5000 LCR meter), and it would be pretty easy to whip up a 2 wire pair as well.
Metric or Imperial DMM? - Page 1
Forum section: electronics / testgear

author: elex_enthusiast
author_rank: Regular Contributor
timestamp: April 03, 2016, 03:15:40 am
content: DMM=Digital Machinist's Meter

author: gardner
author_rank: Regular Contributor
timestamp: April 03, 2016, 03:40:40 am
content: I really like This Old Tony's videos. Aside from the April fools, they have a sense of humour that appeals to me.
Analogue Discovery 2 - Page 1
Forum section: electronics / testgear

author: Snikwah
author_rank: Contributor
timestamp: March 27, 2016, 07:23:36 am
content: Hi AllBeen lurking here a bit but this is my first post.I watched the video blog on the Analogue Discovery. Seems like a nice neat unit for the price and the software seemed very versatile.I'm not sure if Dave catches all of the posts here, but if so, I'm wondering if he might be able to do a review/comparison on the new Analogue Discovery 2 verse the Analogue Discovery. I'm thinking of getting one particularly for the low frequency network analyser function. Nice stuff. I realise it doesn't cut the mustard when compared to the professional stuff, but for my limited use of the gear I can't justify the expense of a professional Network Analyser. Actually, the truth is that I would buy one but the Mrs would kick me out of home and you can do lots with test gear but you can't cook food in it or use it for a pillow.Regards Brad.

author: Mark
author_rank: Frequent Contributor
timestamp: March 27, 2016, 11:55:55 am
content: The only hardware difference between the two is the improved power supplies on the Version 2.I have the version 1 and it has proved to be a very useful tool which had paid for itself many times over.

author: hopski
author_rank: Regular Contributor
timestamp: March 27, 2016, 12:16:01 pm
content: You might find this useful

author: 4cx10000
author_rank: Regular Contributor
timestamp: March 27, 2016, 01:51:50 pm
content: Very useful little piece of equipment. Recently I have used the Analog Discovery along with Jaxbird's software Audio Analyzer Suit - just excellent! Well, think I would not consider a purchase of the V2 after looking at tomtektest video. Of course, the upgrade of the psu would probably come in handy.

author: Quiggers
author_rank: Contributor
timestamp: April 02, 2016, 07:48:41 am
content: I also have the analog discovery 1. I use it daily at my day job for low voltage work. I would recommend it and advise you to pick up the scope and awg breakout board.The built in logic analyser with all the decoding options have saved my bacon a few times.There is also the ability to us the device as a front end for automated testing via python or c++ . A real boss pleaser.

author: rstofer
author_rank: Super Contributor
timestamp: April 03, 2016, 01:50:40 am
content: I had forgotten about the Network Analyzer. On another forum, we got into a discussion of tuned circuits and I just breadboarded them up and used the NA to check frequency and phase response. That is a NEAT feature. The math is nice, the math is perfect but a plot tells the real story. I guess I learn from doing...

author: Snikwah
author_rank: Contributor
timestamp: April 03, 2016, 03:05:18 am
content: Hi AllThanks for the replies. I will have to add this to the very soon to be realised wish list.RegardsBradSent from my SM-T805Y using Tapatalk
Anyone have a Kepco JQE36-15 service manual?  - Page 1
Forum section: electronics / testgear

author: iampoor
author_rank: Frequent Contributor
timestamp: April 02, 2016, 06:31:57 am
content: HiWOndering if anyone might have the service manual for this? Or own a unit?I am trying to figure out the values for the current and voltage adjust pot. I got one of these without any control pots.Trying to not spend 200$ for the service manual on a very cheap purchase...

author: kanuk
author_rank: Contributor
timestamp: April 02, 2016, 02:37:43 pm
content: http://mmrc.caltech.edu/Other/Kepco%20JAE%2025-20%201.pdfand here:http://physics.ucsd.edu/neurophysics/Manuals/Kepco/JQE%206-22M.pdf
effective - Page 1
Forum section: electronics / testgear

author: GEuser
author_rank: Frequent Contributor
timestamp: April 01, 2016, 03:33:34 am
content: Q

author: DimitriP
author_rank: Super Contributor
timestamp: April 01, 2016, 04:19:38 am
content: Here is a write-up from 2003 aimed at self constructionhttp://www.mmccs.com/mmarc/n0ss/dl_30w_hf-uhf.pdf

author: joeqsmith
author_rank: Super Contributor
timestamp: April 02, 2016, 03:49:47 am
content: Quote from: DimitriP on April 01, 2016, 04:19:38 amLooks good. I attempted to assemble a sort of amplifier kit at one time along with a dummy load. This worked out pretty well for testing an old current probe I was attempting to modify. Load has a built in monitor port which has been handy. I was putting a fair amount of power into it (over 50W) but a lot of air flow.https://www.eevblog.com/forum/projects/home-made-pa-and-load/msg635912/#msg635912
giving a HP1650 for almost free - Page 1
Forum section: electronics / testgear

author: iso14000
author_rank: Contributor
timestamp: March 25, 2016, 09:38:27 pm
content: HII have saving up an old HP1650 from my company trash, It wake up properly but I don't have system disk and I'm not sure that it works OK.If somebody wants it .... for spare part

author: TAMHAN
author_rank: Frequent Contributor
timestamp: March 26, 2016, 05:35:15 pm
content: Hello,I would move this to the buy and sell thread, it gets more attention there.Do you think it can be shipped to Slovakia?

author: robert_
author_rank: Regular Contributor
timestamp: April 01, 2016, 06:27:17 pm
content: I would have working boot floppys for it.

author: Martini
author_rank: Regular Contributor
timestamp: April 01, 2016, 07:17:47 pm
content: I just downloaded the operating software, pretty incredible it's still online 20 years after its release date!(I live in France if that helps for the shipping)
How does MDO3000 RF trigger work? - Page 1
Forum section: electronics / testgear

author: luisprata
author_rank: Regular Contributor
timestamp: March 31, 2016, 10:47:37 am
content: Hi,I wonder how MDO3000 RF trigger works.It`s possible to trigger it by an external trigger?I would like to use another scope to view time correlated waveforms. (almost like MDO4000) It would be possible?Thanks.

author: Howardlong
author_rank: Super Contributor
timestamp: March 31, 2016, 02:01:22 pm
content: No, unlike the MDO4000, the MDO3000 does not offer time correlated triggering.Either you operate the MDO3000 as a scope or you operate it as an SA, both cannot be operated at the same time, again unlike the MDO4000.This restriction is not very well communicated IMHO by Tek marketing, probably deliberately so.

author: luisprata
author_rank: Regular Contributor
timestamp: March 31, 2016, 09:17:24 pm
content: Yes,I`ve seen on EEVBlog teardown video that it seems to use all ADCs sample rate to RF. So you really can't use RF and time at same time.But my question is about using 2 equipments ... MDO3000 as SA and another scope to see time domain.But to use it, I would need to source an external trigger input to start Signal Analysis. Or some external trigger from SA to synchonize the second scope.Well, the main question is if there is a way to get or source some trigger to SA in MDO3000.Certainly, there is no easy way to do it, but I`m thinking about some internal hack or something.I`ve seen an unmounted Trigger input in teardown. And There is an "spectrum run free" menu button.Thank you again.

author: Howardlong
author_rank: Super Contributor
timestamp: March 31, 2016, 09:55:59 pm
content: I had a quick look just now and the only way it seems to operate is with continuous free run mode, or stopped. i couldn't find a way to trigger it externally. It's not my main SA so I don't use it a great deal as an SA, so it's possible I've missed something, but the settings in SA mode are pretty rudimentary.Obscurely you can enable the scope's trigger menu while in SA mode, but it doesn't affect the SA sweep, I did try.There is a non-changeable menu item "Spectrum Free Run", I don't know why it's a menu item, you can't do anything with it as far as I can tell, but to be fair the UI is a bit of a dog's dinner so I might not have the right telepathy rating for changing it.
Lavolta Variable Linear DC Bench Power Supply - Is it any good? - Page 1
Forum section: electronics / testgear

author: haggar
author_rank: Contributor
timestamp: April 01, 2016, 12:50:05 pm
content: Hey all,I was hoping to get some building/testing done this weekend, but it's time for me to get a bench power supply. The only one I can find with delivery for tomorrow is this:http://www.amazon.co.uk/Lavolta-Variable-Linear-Bench-Supply/dp/B019KL4G6I/ref=sOn the face of it, it seems OK, but I'd really appreciate some honest input.The stuff I'm mostly working with at the moment is extremely low power stuff, like 5.0V at around 450mA, so I don't need anything too crazy, but I need a supply that can go low enough.Any input or advice would be super.Ta.

author: rdl
author_rank: Super Contributor
timestamp: April 01, 2016, 04:36:10 pm
content: That is probably the most copied/knocked off/re-branded power supply design in the world. Some will be good, others will be pure garbage. Unfortunately, that means you have little hope of knowing which you bought until you get it and open it up. The brand name does not inspire hope.
Oscilloscope C1- 79 problems - Page 1
Forum section: electronics / testgear

author: teslapand
author_rank: Newbie
timestamp: March 29, 2016, 10:50:44 am
content: Hello all,I have got an old Russian oscilloscope C1-79 that wasn't working well.(http://www.izmer-tech.narod.ru/oscil/oscil.html)With power on, everything looks like ok.All controls on the front panel appear to function normally.The two traces appear correctly, brightness and focus going well.I tried with sinusoidal signal at the entrance A and B, signal was synchronized well.The oscilloscope works very well until 20 minutes.After 20 minutes R68(5,1 ohms) from power supply(?22.044.072 ?3) heats very strong.At the same time happens next:-transistor T1(2T808A) [?23.211.029 ?3] heats strong.-current through fusibile ??(2A) [?23.211.029 ?3] rise from 0,34 A to 1,02 A.-tension bar (27V) - collector T1 [?23.211.029 ?3] decreases from 32 V to 19 V-brightness and focus decreases very much so the traces disappear.-fan rotation speed decreases(the pwer supply of the fan is 27 V)After I power off the oscilloscope and it is getting cold, again the oscilloscope works well.I checked fan and it is ok.I checked T1(2T808A), T4(2T602b) C3, C4(1uF)[?23.211.029 ?3] and it is ok.I untied the terminal 7 from transformer (T?) [?23.211.029 ?3] but still persisted the same defect.Anyone have any ideas fixing this problem?!Thank and sorry for my poor english.

author: teslapand
author_rank: Newbie
timestamp: March 30, 2016, 06:55:31 am
content: The russian figures does'nt appears in this topic!?!

author: TAMHAN
author_rank: Frequent Contributor
timestamp: March 31, 2016, 01:19:15 am
content: Do you have access to cold spray?Maybe selectively spraying, thereby cooling, parts of the planar might help!

author: teslapand
author_rank: Newbie
timestamp: April 01, 2016, 10:04:08 am
content: So, you are saying to use cold spray to indentify the defective part.It might be a bad idea, I might damage something else with spray.Anyway, I do not have cool spray.This malfunction of the oscilloscope might be common for russian oscilloscopes, because another friends of mine tell me that their oscilloscope have the same malfunction.

author: MK14
author_rank: Super Contributor
timestamp: April 01, 2016, 10:20:00 am
content: Quote from: teslapand on April 01, 2016, 10:04:08 amYou are suppose to use, special cooling/freezing "gas" cans. These are made out of inert gases, which are relatively safe to use on electronics. As long as you don't use it too much, and freeze up moisture in the air, and end up getting the electronics wet, that way.

author: GEuser
author_rank: Frequent Contributor
timestamp: April 01, 2016, 10:26:36 am
content: Seems like big drop on T1 collector , I'd follow the emitter to see where goes , I could not follow where 8----9 goes .Just a thought ...

author: wraper
author_rank: Unknown
timestamp: April 01, 2016, 10:46:46 am
content: Quiet obviously problem is not in the PSU. You should look into the high voltage converter (Y15). The worst you might have is that voltage multiplayer is toast.
[teardown] NoiseCom UFX99CA 1 Ghz Programmable Noise Generator - Page 1
Forum section: electronics / testgear

author: Earendil
author_rank: Regular Contributor
timestamp: April 03, 2016, 01:48:26 pm
content: I bought this unit very cheaply on Ebay. It's quite impressive in the inside I think.Datasheet:https://accusrc.com/uploads/datasheets/5930_ufx99ca.pdfMy unit has options U9opt01, U9opt05.It had 75 Ohm inputs but actually it used minimum loss pads to convert from 50 Ohm. Everything else is 50 ohms inside. I've already removed the minimum loss pads and I need to replace them with attenuators. I've also removed and reused for the conversion of the unit to 50 ohm some of the connectors on back. (I don't need 4 external filters).Unfortunately one of the 6 pole RF relays was stuck after some initial usage and burned the driver IC (over current). I found the same type relays on Ebay and they've already been installed on the pictures. After this event I found out that there's some extra noise (10kHz pulses, so the noise floor is not flat at those frequencies anymore) coming from the power supply which I removed to investigate. It's pictured separately. I don't have too much time to work on this so that why it's not fixed and installed back yet.I've also dumped the software for the unit for backup purposes. I included that too.Enjoy.

author: Earendil
author_rank: Regular Contributor
timestamp: April 03, 2016, 02:02:40 pm
content: (Same picture as before with somewhat improved colors).

author: Earendil
author_rank: Regular Contributor
timestamp: April 03, 2016, 02:17:35 pm
content: And this is one of the minimum loss pads.
Gould Oscilloscope DataSys, 9500 etc - Page 1
Forum section: electronics / testgear

author: Jester
author_rank: Frequent Contributor
timestamp: December 11, 2015, 09:47:38 pm
content: Does anyone out there have a Gould Oscilloscope either a DataSys, 9500 or similar that has the 8 pin circular probe power connector on the back?If you do I would really appreciate if you could measure the voltages on the probe power connector. I have a Gould Differential probe that I would like to use with another scope, however I can't use it because I don't know the pin-out of the probe power connector. The connector has 8 pins and the center pin is most likely ground as a black wire is connected to it, and various other colored wires connect to the remainder of the pins. The connector looks like this:Much appreciated.[imghttp://forum.allaboutcircuits.com/attachments/con1-png.96342/

author: Jester
author_rank: Frequent Contributor
timestamp: March 24, 2016, 05:26:35 pm
content: No response in 3 months, I thought I would resurrect this post to see if anyone has any input.

author: TAMHAN
author_rank: Frequent Contributor
timestamp: March 24, 2016, 08:14:22 pm
content: AFAIK, there is a German company which handles all the service for the Gould Nicolet instruments now. Dont know the name, but can look it up if you so desire. Maybe asking them will help

author: Jester
author_rank: Frequent Contributor
timestamp: March 27, 2016, 09:23:30 am
content: I did a google search, the only reference I found was Gould Nicolet Meßtechnik GmbH, however they seem to be closed.If there is someone else please let me know.Thank you

author: TAMHAN
author_rank: Frequent Contributor
timestamp: March 27, 2016, 05:37:05 pm
content: Not 100% sure, but it could be these guys:http://www.mess-und-datentechnik.com/en/produkte/I can darkly remember them as I wanted to buy a GOuld Ultima some time ago, but missed it on ebay for being cheap. I was stoopid

author: Jester
author_rank: Frequent Contributor
timestamp: March 27, 2016, 08:39:07 pm
content: Thank you, I sent them an email.

author: TAMHAN
author_rank: Frequent Contributor
timestamp: March 29, 2016, 07:30:23 pm
content: If the language barrier is high, hit me up. tamhan aht tamoggemon ball com.They are likely to have it or to know where to get it. But it is unlikely to be cheap...labor costs are insanely high in the BRD. Insanely, insanely high.
Using NI HW stuff without NI SW (or free NI software)? - Page 1
Forum section: electronics / testgear

author: daqq
author_rank: Super Contributor
timestamp: March 30, 2016, 07:40:33 pm
content: Hi guys,I've got a NI 6009 and it looks like a nice thingie. However, I haven't got LabVIEW or anything else. Is there any free way I can play around with NI hardware stuff without purchasing the LabVIEW sotftware?Thanks,David

author: xyrtek
author_rank: Regular Contributor
timestamp: March 30, 2016, 08:09:57 pm
content: Hi,I have used (against my will) NI hardware, usually with the .NET API. (including usb daq)Search around and check the drivers available etc.http://www.ni.com/datasheet/pdf/en/ds-218From the datasheet this are other options they mention:ANSI C/C++LabVIEWLabWindows/CVIMeasurement StudioSignalExpressVisual Basic .NETVisual C#
GPIB software - Page 1
Forum section: electronics / testgear

author: McBryce
author_rank: Super Contributor
timestamp: March 30, 2016, 09:54:17 am
content: Hi all,I'm trying to set up a small test at home and I'm finding it hard to find the right software solution. Here's what I have and what I need to do:I have a Keithley 2000 and a HP3478A, both with GPIB. I also have a (real) Agilent 82357A and a PC of course. I'd like to control and read data from these two instruments without spending a fortune on software.At work we have several software packages (LabView etc) with which I could easily do this, but they don't quite fit into my hobby budget and I'd like to use the setup for longer than a 45 day trial period (thanks a bunch NI).What would you guys recommend?McBryce.

author: PigSpark
author_rank: Contributor
timestamp: March 30, 2016, 10:31:56 am
content: My last company used Visual Basic 6 to control a test rig for calibrating instruments.VB6 ran on a touch screen PC and communicated with NI DAQ gear just fine. A lot of the code samples for their gear had VB6 examples.

author: Lukas
author_rank: Frequent Contributor
timestamp: March 30, 2016, 10:44:40 am
content: Just use the programming language you are familiar with. Odds are that there are VISA bindings for it.

author: McBryce
author_rank: Super Contributor
timestamp: March 30, 2016, 11:35:59 am
content: I have Visual C and Visual Basic (and can program them). It just seemed like a lot of work, when someone had possibly already written some nice frontend that I could useI suppose I'll end up writing my own, now that my "lazy solution" doesn't seem to be available.McBryce.

author: edpalmer42
author_rank: Super Contributor
timestamp: March 30, 2016, 05:25:40 pm
content: Since you've got Labview at work, why not use Labview Home?http://store.digilentinc.com/labview-home-bundle/If you don't like that, there are various free languages with GPIB extensions or modules. A couple that come to mind are PyVisa and EZGPIB.Ed

author: McBryce
author_rank: Super Contributor
timestamp: March 30, 2016, 07:18:22 pm
content: I found EZGPIB while browsing, but I hadn't looked at it fully yet. One of my Test engineers then mentioned the LabView Home option and it looks like I'll go for that optionMcBryce.
Siglent SD1202X Update - Page 1
Forum section: electronics / testgear

author: hendrix
author_rank: Contributor
timestamp: March 26, 2016, 07:22:15 pm
content: Hello,I am trying to update a new Siglent SDS1202X oscilloscope and its been like 20 mins since the "updating 100%" came up but it still has not said "success" like the firmware update pdf states. Should I keep waiting or should I restart or pull the USB out or what should I do? Help would be appreciated. Thanks.

author: hendrix
author_rank: Contributor
timestamp: March 26, 2016, 07:28:15 pm
content: Forgot the pic

author: tautech
author_rank: Super Contributor
timestamp: March 26, 2016, 07:35:53 pm
content: Re-boot it.I had exactly the same issues with a couple of units I upgraded before sale.Early FW did not display "Please power cycle DSO" or words to that effect.Later versions do.IIRC a new FW version mentioned this problem as being fixed in the FW changelog.BTWCheck the System info in Utilities for your new FW version as a sanity check that all has gone well.

author: hendrix
author_rank: Contributor
timestamp: March 26, 2016, 08:09:36 pm
content: Oh, thank you...saved a headache? Btw, what do you think about the differences between this and a sds2202x, is the 2000x series worth the extra dollar? I might be tempted to send this back and get that if the differences are worth it. Thanks.

author: tautech
author_rank: Super Contributor
timestamp: March 26, 2016, 08:28:48 pm
content: Quote from: hendrix on March 26, 2016, 08:09:36 pmThe SDS2000 and 2kX series are in a different class, the 2kX series has 10 time the memory depth, double the sampling speed, ~3 times the wfm/s capture rate, MSO front panel connector(if you require MSO at a later date) and the AWG is already incorporated in the PCB should you wish to activate that option later.The one thing the SDS1000X seriesdoeshave is a full BW 500uV/div range whereas the SDS2000X series max sensitivity is 1mV/div @ full BW.(not 20 MHz limited)The UI is quite similar in both of these series as they share similar Siglent V2 FW.

author: firworks
author_rank: Unknown
timestamp: March 28, 2016, 06:14:52 am
content: I just went through the update as well, and video'd it for future updaters who are unsure about the process or see it getting stuck at 100%:
Tektronix DSA602 Harmonic Distortion Measurement ? - Page 1
Forum section: electronics / testgear

author: Johnny10
author_rank: Frequent Contributor
timestamp: March 26, 2016, 03:18:07 pm
content: I am trying to determine if the DSA 602 is different from the DSA 602A.In the DSA 602A manual it shows a measurement window that allows for selection of Spectral Frequency, Spectral Magnitude & THD.On my 602 I find no such window.I have continued checking different manuals on this and I guess the 602 does not have the added features outlined in the DSA602A Manual.

author: edavid
author_rank: Super Contributor
timestamp: March 26, 2016, 04:04:43 pm
content: Quote from: Johnny10 on March 26, 2016, 03:18:07 pmThe main hardware difference is that the DSA602A has the floppy drive, but of course DSA602As have later firmware as well. So maybe you could upgrade your DSA602 EPROMs to get that function.(Of course a DSA602 is never going to be a very good THD analyzer, due to digitizer limitations.)

author: Johnny10
author_rank: Frequent Contributor
timestamp: March 27, 2016, 03:42:19 pm
content: Could you explain the THD digitizer limitations.I have available in my area a broken DSA602A that I might be able to use as a parts unit for low dollars.Of course I realize this FFT only good to -60 to -70dBData sheet from DSA 602AMeasurement SystemAmplitude: Min, max, mid, mean, p-p, gain, RMS, overshoot, undershoot, area +, area -, and energy.Timing: Rise, fall, width, delay, main-to-window trigger time, period, propagation delay, cross, phase, frequency, duty cycle, and skew.FFT: Fundamental track, harmonic amplitude, frequency, and total harmonic distortion.Statistics: Available for any measurement listed above for both live acquisitions and groups of stored waveforms.Cursors: Single or dual dots, split or paired mode, horizontal and vertical bars, and measurement-zone delimiters. Delta volts, delta time, 1/delta time, and slope.Waveform ProcessingWaveform Functions: Absolute value, average (exponential and summation), convolution, correlation, delay, dejitter, differentiate, envelope, exponential, FFT filter, FFT integrate, interpolate, log, natural log, pulse, signum, smooth, and square root. Live waveforms can be changed by using adjustable parameters.Arithmetic Operators: Add, subtract, multiply and divide.FFT: Magnitude and phase; real and imaginary; inverse FFT, correlation, and convolution; six window functions; Typical Noise Floor: -60 dB; -70 dB with averaging.Act on Delta: Save, repeat, chime, SRQ, and hardcopy.Histograms: Vertical or horizontal histograms generated from a user-defined portion of any waveform. Statistical information is provided for histogram data.

author: edavid
author_rank: Super Contributor
timestamp: March 27, 2016, 05:18:11 pm
content: Quote from: Johnny10 on March 27, 2016, 03:42:19 pmJust that you only get 32K points at 8 bits.

author: Johnny10
author_rank: Frequent Contributor
timestamp: March 27, 2016, 07:24:45 pm
content: I found a Service manual for DSA600 series that talks about certain features only available after Firmware 2.0.Mine is older 1.3 version
peek  - Page 1
Forum section: electronics / testgear

author: GEuser
author_rank: Frequent Contributor
timestamp: September 20, 2014, 10:28:58 am
content: Q

author: IZ1FID
author_rank: Newbie
timestamp: May 18, 2015, 01:25:40 pm
content: Hi to all I already have an SPM-19 but I saw for sell an SPM-19 that report a factory BN 853/02 IEE488 interface marked POST BP, this POST BP is reported also on the front panel near the W&G logo.My question is :1what means2how this affects the operation of SG-4 Display UnitThanks. Federico IZ1FID

author: Martin.M
author_rank: Frequent Contributor
timestamp: March 27, 2016, 04:13:59 pm
content: Quote from: IZ1FID on May 18, 2015, 01:25:40 pmhello Federico,the german POST was for a very long time the monopolist in service of phone and all kind of Radio, TV and wireless communication.As a part of the state they used also a very lot of test equipment to check and control allover phone systems and RX TX of any who use that.The office name of the HF part of the Post was "Fernmeldeamt", following the city name where the Fernmeldeamt is standing, so this also may be written anywhere on the gear.The Tag POST is simply the information that this test gear you have there was owned and used by the german Post. There is no relation to the functionallity, all will be original now.greetingsMartin
Velleman HHS5 Handheld Oscilloscope Teardown (1997) - Page 1
Forum section: electronics / testgear

author: ROBOT
author_rank: Contributor
timestamp: March 26, 2016, 05:33:45 pm
content: Took it apart to remove the corroded batteries.Here are the pictureshttps://imgur.com/a/9rJMLQuite a few interesting things:You think those golden QC pass stickers are bad well check out the QC horribly hand written in what else then the loctite/glue they used to hold the screws to the pcb! Such quality!Check out the extremely tall 20MHz crystal it's taller than most of the caps on the board!Nice spring loaded contact that touches the shielding foil.Appears to be 1 custom ASIC made by velleman on the schematic it's labeled RY1 any ideas? It's a strange 8 pin packageThe board looks to have been designed as a 1 layer with jumpers but then updated to a 2 layer later. Also can see some extra long headersThe AA battery holders connect to a 9v battery snap! Surely this is not a great idea! What happens when someone plugs in 2 9v's instead! Surely this had to have been a custom part.The PC connection (rs232) uses a 3.5mm audio port. They sell a special optically isolated cable.Here is the manual with schematic if anyone is interested.http://www.vellemanusa.com/downloads/0/usermanual_k7105.pdf

author: SeanB
author_rank: Super Contributor
timestamp: March 26, 2016, 08:15:34 pm
content: Ry1 is a reed relay, probably a single NO contact with a 5V coil. Those 3 AA cell holders with the PP3 snap connector are actually a standard part, the snap makes it easy to remove from the battery compartment to change batteries and to replace if they leak and rust the metal springs.

author: Fraser
author_rank: Super Contributor
timestamp: March 26, 2016, 08:39:52 pm
content: The HHS5 is a VERY early Velleman handheld digital oscilloscope that was available both as a kit and fully assembled. It was an affordable option for hobbyists and paved the way for the more refined HPS5, HPS10 and HPS40.The performance of all of these Velleman budget scopes is less than great however. Sample rates are low and they are best limited to automotive and audio work.Fraser

author: ROBOT
author_rank: Contributor
timestamp: March 26, 2016, 10:35:25 pm
content: Quote from: Fraser on March 26, 2016, 08:39:52 pmNice to know! I actually got it for free! It does actually work still! Almost 20 years old. Right now it's my only scope at home. Planning on getting a rigol 1054z.I am surprised those 3 cell holders are standard. I imagine it could cause lots of damage if you don't put in the right regulator.

author: Lightages
author_rank: Unknown
timestamp: March 26, 2016, 11:33:47 pm
content: I built an HHS5 kit back in the 90s. It was fun to build and for its limitations it is a nice handheld scope. By today's standards it is woefully inadequate but for free, great deal!
A capacitor tester for large electrolytics (>20,000uF)? - Page 1
Forum section: electronics / testgear

author: cvanc
author_rank: Frequent Contributor
timestamp: March 26, 2016, 09:16:07 pm
content: Can I get pointers to a cap tester that will measure (at least) the value and ESR of electrolytics in the 20,000uf up to maybe 100,000uf range?Just got a DE-5000 and while I'm sure it will be very useful it tops out at 20,000uF. Thanks for any input!

author: HighVoltage
author_rank: Super Contributor
timestamp: March 26, 2016, 10:01:14 pm
content: The Fluke PM6304 or PM6306 can measure capacitance from low pF to something like 31FIt also has a internal 2V DC bias (up to 40V external) for electrolytic measurements and ESR measurement
EMC Antenna cheep vs very expensive - Page 1
Forum section: electronics / testgear

author: Bob S
author_rank: Contributor
timestamp: March 26, 2016, 02:10:39 am
content: I am trying to get some idea of my radiated noise levels at a meters or so to see if I can pickup and correlate some of what my near field probes are seeing. My unit has failed in the test labs between 30 and 300MHz so this is the only frequency of interest.My question is, short of spending thousands on a calibrated antenna what might I expect to get out wide band scanner antenna such as this one?http://www.ebay.com/itm/Taurus-25-1300-mhz-Scanner-Ham-General-Coverage-Discone-antenna-/301908583528?hash=item464b276468:g:Y-cAAOSwB4NWuj9YThanks

author: joeqsmith
author_rank: Super Contributor
timestamp: March 26, 2016, 03:20:18 am
content: Maybe better luck posting in the radio section?
Panel meter info - Page 1
Forum section: electronics / testgear

author: orbanp
author_rank: Regular Contributor
timestamp: March 25, 2016, 04:50:53 pm
content: Hello Everyone,Some time ago I got a panel meter from eBay, similar to this:http://www.ebay.com/itm/Dual-LED-DC-5A-30V-4-Digit-Digital-Ammeter-Voltmeter-LCD-Panel-Amp-Volt-Meter-/311514735640?hash=item4887b9a418:g:SrkAAOSwk1JWg1ZMOnly difference is that mine does not have the built in shunt (not installed).Is there any documentation on the design of this meter?Any project page, similar to what the LCR-ESR-transistor-tester has.Thanks, Peter

author: mos6502
author_rank: Frequent Contributor
timestamp: March 25, 2016, 08:23:51 pm
content: Not really about your meter, but ...
Diagram/schematic for HZ56 PR-30 - Page 1
Forum section: electronics / testgear

author: RavenSpy
author_rank: Contributor
timestamp: March 25, 2016, 11:35:57 am
content: Hi everybody,I'm looking for schemes of a current probe for oscilloscope, namely Hameg HZ56 probe. Yes, I know I could do it myself, but if someone has will save me some time.I have tried to contact Hameg, tell me that they do not have because they don’t make it (LEM does), contact LEM for schemes PR30 probe, they tell me that about 10 years ago that Fluke is responsible for its products, contact Fluke for PR30 probe, they tell me that they have nothing. Yes, I know, with all this time I had finished doing before myself ...Thanks in advancePS: If at the end no one have it, i will do it and upload it