free DSO for electronics beginner? - Page 1
Forum section: electronics / general

author: cyndernight
author_rank: Contributor
timestamp: June 17, 2018, 03:34:50 am
content: hianyone got a DSO laying around they dont want?prefer if it works but i can try doing basic troubleshooting on it if its not 100%doesn't need to be super duper accurate or amazing..just using for low level and hobby things... something for me to experiment and play with.can drive to get it... im in Woolongong, its about half hour south of Sydney...anyone got one laying about?

author: aargee
author_rank: Frequent Contributor
timestamp: June 17, 2018, 03:54:24 am
content: You might want to search the forum for similar topics to get a feel for the requirements of such requests from the forum community.

author: Mr. Scram
author_rank: Super Contributor
timestamp: June 17, 2018, 04:06:10 am
content: If you can drive and spare gas, I suppose you can spare some cash for a DSO right?

author: cyndernight
author_rank: Contributor
timestamp: June 17, 2018, 04:09:15 am
content: Quote from: aargee on June 17, 2018, 03:54:24 amthank you for your time to respond to me.im not sure i follow? did i say something wrong?im not aiming to pity or scam anyone, this is literally a "would be awesome" for me to experiment with while im unemployed.but i dont intend to try and coax someone to part with anything unwillingly... i was more asking"anyone throwing it out, if so let me know" kinda thing...its not a NEED for me to have this, nor is it for any impotent project i have in mind...just being honest and on the level, i joined to ask if anyone was tossing one, or know where i can get one.if not, thats cool, if they do then great. <3Quote from: Mr. Scram on June 17, 2018, 04:06:10 amat the moment im using the parents car (and there fuel) while i'm between jobs.if i knew in advance how much something was, and had a week or two i might be able to find some cash yes, but i dont know how much nor how quick.

author: cyndernight
author_rank: Contributor
timestamp: June 17, 2018, 04:20:37 am
content: as an addendum:i wasn't intending to upset or stop on anyone's toes here.if this has caused some upset or is taken negatively im happy to delete this posting and withdraw the questioni had no intent to upset or offend

author: Ian.M
author_rank: Super Contributor
timestamp: June 17, 2018, 04:27:34 am
content: You are a very new poster, so as you have no 'track record' here, you need to make the case for why *YOU* are more deserving of a freebee than anyone else in limited circumstances. Also, you need to give your location, down to city or nearest major town, unless you are proposing that you are willing to drive the whole Outback Highway in the 'rents car on their fuel card to pick one up.

author: bitseeker
author_rank: Super Contributor
timestamp: June 17, 2018, 04:28:22 am
content: cyndernight,Welcome to the forum. I don't know how long you may have been reading the forum prior to signing up. In any case, most would agree that it's generally bad form to make your very first post on a forum one that is asking for handouts. It'd be akin to walking into a ballroom full of engineers and the first thing you do is shout, "Hey, can anyone give me a digital oscilloscope for free?"As aargee said, you may want to do some homework first. Then, invest some time into the forum and the people on it. You may be pleasantly surprised by what happens thereafter. No guarantees, of course.

author: cyndernight
author_rank: Contributor
timestamp: June 17, 2018, 04:43:33 am
content: Quote from: Ian.M on June 17, 2018, 04:27:34 amthis is true i have no record, and to be blunt i would rather if there is someone in critical circumstances that they get the scope over me.i make no bones about this, this is a "would be nice to experiment with" since i play with arduinos from time to time, it would be nice to have but just that, would be nice.if there is a choice between me and someone who needs it, please, the other guy.im only asking if its going to be tossed, sitting doing nothing a spare or otherwise "not needed anymore"... no guilt tripping or pitty at all.Quote from: bitseeker on June 17, 2018, 04:28:22 amhi there bitseeker!ive known about the forum a little while (EEVblog YouTube channel) but always felt it was too... "hardcore" for me, my knowledge is very basic and my skills crude at best, so i felt it was best i just stayed out of it... as honestly i don't know i have anything worth anything to contribute.all my knowledge is old, basic and archaic... its not an unwillingness to contribute but more a "what could i possibly offer" that everyone else doesn't know of the back of there hand when they were in nappies?as for the ballroom thing, yeah, it felt like that when i posted it, and was fully braced for the burning backlash of the internet.. but if i sat outside and spent the time wondering, i wouldn't get anything either...worst case, im told to get lost... i shrug say sorry and leave... but on the slim to non chance i might find a lead, its worth asking.

author: Ian.M
author_rank: Super Contributor
timestamp: June 17, 2018, 05:17:15 am
content: Thanks for editing in your location.I suggest either introducing yourself:https://www.eevblog.com/forum/chat/new-member-please-introduce-yourself/or jumping right in and starting a topic about a (hopefully) interesting project you are working on. Don't worry about your current lack of experience - we all originally started with a simple battery, torch bulb and switch in a series circuit, or something equally simple once, and without a steady stream of newbies this forum would be a much quieter and more boring place, without enough questions to keep the experts and other experienced members occupied.The more people get to know you, the better your odds of one of them digging a DSO dinosaur out of their loft.

author: bitseeker
author_rank: Super Contributor
timestamp: June 17, 2018, 05:25:59 am
content: Well said, Ian.

author: tggzzz
author_rank: Super Contributor
timestamp: June 17, 2018, 07:13:45 am
content: Quote from: cyndernight on June 17, 2018, 04:20:37 amDon't worry about that kind of thing; you were upfront and inoffensive - but also ineffective!There are ways of asking questions that are more likely to get helpful responses. My take on that is athttps://entertaininghacks.wordpress.com/library-2/good-questions-pique-our-interest-and-dont-waste-our-time-2/Obviously not all that is relevant to this discussion, but it is frequently useful in other discussions.

author: cyndernight
author_rank: Contributor
timestamp: June 17, 2018, 09:48:20 am
content: Quote from: Ian.M on June 17, 2018, 05:17:15 amwell i have a few projects going on i guessi have 2x 3D printers here im working on...got a home made multi voltage current settable PSU in for repair... (currently swinging voltage wildly)got a USB battery bank that runs from solar power...i got my massive home made DIY speaker set... 8x 6.5'' speakers and a 12'' sub in 1 "portable" box, runs on battery's... that's kinds cool i guess?home made LED strip lighting? got that around the place...got a small electric brush-less buggy i built? that's neat i guess?but, that's all basic stuff, probably nothing new to anyone here...

author: cyndernight
author_rank: Contributor
timestamp: June 17, 2018, 11:55:22 am
content: i do have a question, if theres anyone watching this anymoredave talks about floating earths and scope grounds...he doesnt mention the most asked question... why not just put tape on your scopes earth to make the scope float?seen AVE do it, hes still alive...

author: BNElecEng
author_rank: Regular Contributor
timestamp: June 17, 2018, 12:10:15 pm
content: It's not safe, that's the bottom line.If someone is careful and knows what they are doing then they would probably be fine. But that is one massive IF.When the earth to an oscilloscope is removed, then the metal work on the front of the scope will be at whatever potential the ground clip is attached to. This could easily be connected to a lethal potential relative to earth. Now imagine that someone, who isn't you and doesn't know that that the earth is disconnected, goes and touches the BNC connector of one of the channels. Zap! it's very easy to accidentally brush up against the metalwork.Do you have a measurement you want to make where you think you need the scope to float?

author: cyndernight
author_rank: Contributor
timestamp: June 17, 2018, 12:29:54 pm
content: Quote from: BNElecEng on June 17, 2018, 12:10:15 pmfair enough, he talked about the transformers to make it float and was curious why he didnt touch the most common way to "float" something... sparkies tape.me? doubtful, im too chicken and rookie to mess with mains stuff, almost everything i work on is isolated, 5V, 12V or 18V...i have 1 and only 1 project that's "mains rated" and i have a licensed sparky mate help me with that because i know 240 mains is lethal and i have no idea whats "safe" and not...

author: Ian.M
author_rank: Super Contributor
timestamp: June 17, 2018, 12:40:18 pm
content: This comes up several times a year, and we don't *really* need another thread on the subject:https://www.google.com/search?q=site%3Aeevblog.com+float+scopePlease take the time to read several of the generic 'float a scope' threads (you can skip most of the model specific ones), most of which have several posts explaining why its a really bad idea, which can give misleading results, damage equipment and worst case lead to you being fitted for a closed pine box*. If you *still* have questions after doing the research, including reading the links in those topics which give the scope manufacturers opinions of the practice, then ask them and we'll just have to suffer another thread on the subject.Also, do you *really* want to trust your test equipment or even your life to a layer of 'sparkies tape' that's already been compromised by being scuffed by the ground contact as the plug was inserted in the socket?* I cant emphasize enough: A floating scope that isn't specifically designed for the purpose vastly increases the risk of electrocution not only for yourself but anyone who tries to rescue you.

author: sokoloff
author_rank: Super Contributor
timestamp: June 17, 2018, 12:57:49 pm
content: If you’re mostly messing with Arduino stuff, buy a cheap USB logic analyzer first.24 MHz, 8 channel is 24 MHz and 8 channels more than you have now and under US$8.That’s a pretty good starting point, but obviously useless for analog signals.

author: Ian.M
author_rank: Super Contributor
timestamp: June 17, 2018, 02:33:55 pm
content: Yes, if you've got a logic analyser, even an old CRO is good enough for most analog stuff, which widens the potential pool of working or easily fixed scopes that might be available for beer money in the Sidney area considerably.There's also the freeSoundcard Scopeprogram by Christian Zeitnitz. Due to the limitations of your PC soundcard its only got a low maximum sample rate, limited input range of only a volt or two and unless you mod an external USB soundcard, is strictly AC coupled only, but its remarkably capable for what it is. Caution: one mistake probing too high a voltage without a potential divider could kill your soundcard. If its on the motherboard or you are using a laptop you should really get a USB soundcard (make sure its not output only) to minimise the risk.

author: cyndernight
author_rank: Contributor
timestamp: June 17, 2018, 10:34:17 pm
content: Quote from: sokoloff on June 17, 2018, 12:57:49 pmQuote from: Ian.M on June 17, 2018, 02:33:55 pmlogic analyser?i dont know what that is... >.< showing my beginner level information here.

author: Ian.M
author_rank: Super Contributor
timestamp: June 17, 2018, 11:32:59 pm
content: https://en.wikipedia.org/wiki/Logic_analyzerYou should be able to pick up a clone of a Salae Logic 8 for about $20 AUD, and use it (legally) with the open sourceSIGROKsoftware. That will handle just about any digital signal or serial bus you are likely to be working with on an Arduino or similar MCU. If you expect to be developing hardware for old & retro 8 bit computers a clone of a Salae Logic Pro 16 would be better so you've got enough channels to capture a whole 8 bit data bus + the bottom few bits of the address bus + control signals.

author: cyndernight
author_rank: Contributor
timestamp: June 18, 2018, 04:30:54 pm
content: how do i delete this thread?this isn't gunna happen so no point it sticking around here

author: Ian.M
author_rank: Super Contributor
timestamp: June 18, 2018, 04:40:48 pm
content: You can't. IIRC Root posts in threads cant be deleted as it messes up the forum's logical structure, and you certainly cant delete replies from others.Also, deleting legal and inoffensive content that you have posted just because the answers didn't suit you is not going to win you any friends here.

author: cyndernight
author_rank: Contributor
timestamp: June 18, 2018, 04:47:01 pm
content: Quote from: Ian.M on June 18, 2018, 04:40:48 pmwas more thinking no need to have a thread necro and go old, wansnt trying to delete something i didn't like, the thread can sit here for all i care <3just thought it courteous to close - delete a dead thread.

author: Ian.M
author_rank: Super Contributor
timestamp: June 18, 2018, 05:17:33 pm
content: If you want to be courteous, edit the title of your first post to add ' in front of it., but IMHO its neither necessary or advisable unless you have actually managed to get a scope, as threads age into obscurity all the time, and if you continue to hang around and post here, there's still a chance of a scope coming your way if any user in the Sidney area upgrades or is having an old gear clearout.

author: Fred27
author_rank: Unknown
timestamp: June 18, 2018, 06:57:14 pm
content: Nothing in particular against the OP who was at least polite, but it amazes me how often people think they might get a free 'scope just be asking. Would you go onto a petrolhead forum and ask "can anyone give me a free car" as a first post?

author: exe
author_rank: Unknown
timestamp: June 18, 2018, 09:11:28 pm
content: Analog scopes can be got for free or cheap.There are DIY kits like DSO138, was quite usefull, despite very limited specs. I believe it has a very good educational value.

author: PlainName
author_rank: Super Contributor
timestamp: June 18, 2018, 10:38:48 pm
content: QuoteThat might work as often as getting a scope!It can cost money to scrap a car, so an old banger being taken away for nothing could be attractive to the (soon to be) ex-owner.'Course, getting it roadworthy and keeping it taxed and filled with juice is going to cost many times what the car is worth, so perhaps not a perfect analogy.

author: sokoloff
author_rank: Super Contributor
timestamp: June 18, 2018, 10:44:08 pm
content: Quote from: exe on June 18, 2018, 09:11:28 pmAgreed. I was at the MIT Swapfest this weekend and you had your pick of probably 15 or more old Analog scopes in the $50-75 asking price range and I suspect $30-50 would have bought most any of them.

author: Ian.M
author_rank: Super Contributor
timestamp: June 18, 2018, 10:58:29 pm
content: OTOH if I had an old 1980's DSO gathering dust, with a fading green CRT and only 4K sample memory, it might well be 'Free to a good home', though I'd strongly encourage the O.P. to look for a 50MHz or better delay timebase CRO instead as those DSO dinosaurs are an absolute PITA to use and maintain and were often less capable than the DSO138 mentioned above.

author: gnavigator1007
author_rank: Unknown
timestamp: June 18, 2018, 11:09:53 pm
content: Quote from: Fred27 on June 18, 2018, 06:57:14 pmI just would like to remind folks that Dave himself has said on more than one occasion that people on the forum may be willing to part with and have parted with oscilloscopes for free. I don't think it was really an effort to drive a bunch of scope seeking traffic to the forum, but more a way of letting beginners know that these are attainable items at a potentially low cost. I don't understand why outright asking if anybody has a freebie is so often frowned upon. I appreciate that this OP has handled this quite well and if I could help them out I would. You've gotta consider that a significant number of people are coming from youtube and when we react badly to a request for something that the site owner has said has happened before, we end up alienating people that may have much more to contribute further down the road.

author: tautech
author_rank: Super Contributor
timestamp: June 18, 2018, 11:32:36 pm
content: Quote from: gnavigator1007 on June 18, 2018, 11:09:53 pmYeah right and if you remember Dave takes a nice little Tek on a mud run and totally shags it when it could've gone to a scope newbie close to him or be given away in a contest.

author: gnavigator1007
author_rank: Unknown
timestamp: June 18, 2018, 11:49:37 pm
content: Quote from: tautech on June 18, 2018, 11:32:36 pmThis is very true, but you gotta consider the people out there that just watched a few EEVBlog videos on youtube after it was recommended by an algorithm, missed the more tool abusive content, & then came to the forum convinced we're all just drowning in spare scopes & ready to help launch some newbie down the path to fixing their gaming console and spending the rest of their life in the TEA thread. Nobody over there is taking Tek anything on a freakin mud run lol

author: cyndernight
author_rank: Contributor
timestamp: June 18, 2018, 11:57:31 pm
content: Quote from: gnavigator1007 on June 18, 2018, 11:09:53 pmnot gunna lie but this was very similar to what happened... i was looking around for electronics help on the EEVblog YT channel, and he mentioned in a video cheap scopes and to ask the blog as trades / sells / unwanted things can be found there sometimes.i do have some headway on this... asked around, and friends & family put a little pool together for me, ive got 250-300 now... so its no longer "free" but, 250 still isnt much for a DSO... >.<i was trying to get this, rigol DS1054Z... but it went way above my limited gift-budgeting...https://www.ebay.com.au/itm/Rigol-1054z-4-channel-oscilloscope/232808946886?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1431.l2649dave said the DS1054Z was good, but.. yeah... too much now.. so back to square one trying to find a beginner friendly DSO for next to nothing...

author: Ian.M
author_rank: Super Contributor
timestamp: June 19, 2018, 12:36:52 am
content: Yes, that's a bit on the slim side for anything decent even in USB DSOs.Don't forget that bargain basement scopes often don't come with probes and a pair of x1/x10 switchable probes will set you back $50 AUD or more retail. However it wouldn't be a bad idea to go back and edit the thread title to 'Very cheap DSO for electronics beginner and edit the first post to mention you have a limited budget.Don't rule out CROs, you can get a long way with a decent one, though they are no good for capturing essentially random one-off events, and manual protocol decoding of more than a couple of bytes of serial data is a stone cold bitch of a job to do and highly susceptible to human error, even if you can get the device you are testing to repeat the data in a fast enough loop, + output a pulse once per loop for your delay timebase CRO to trigger on.Back in the day, I'd decode serial data manually on a CRO, marking the bits on an acetate taped to the screen, for about two bytes worth, with the Y attenuator set to give me about a 1 div high trace of the data with the clock below it then shifting the delay and both channels Y position for the next two bytes etc. till I either had the whole data packet or ran out of space on the acetate. You couldn't pay me to do that nowadays - my eyes aren't getting any younger and if your business is too cheap to buy basic modern testgear, its probably too cheap to reliably make payroll or pay insurance.If you *ever* find the need to inspect serial data on a CRO, other than checking one repeating byte for levels, risetime and other signal quality issues, its time to get a cheap logic analyser or if your wallet's plump enough, a four channel DSO with protocol decoding like the DS1054Z.

author: cyndernight
author_rank: Contributor
timestamp: June 19, 2018, 02:12:20 am
content: Quote from: Ian.M on June 19, 2018, 12:36:52 amwhat do you think of these two?https://www.ebay.com.au/itm/Siglent-Digital-Oscilloscope-Model-SDS1052DL-50MHZ-2-CHANNEL/332422082983?epid=2256522076&hash=item4d65e671a7:g:paEAAOSwcUBYJRA8https://www.ebay.com.au/itm/Hantek-DSO4072C-Digital-Oscilloscope-2CH-70MHz-Bandwidth-1GSa-s/282955555530?epid=1165254225&hash=item41e17722ca:g:DAQAAOSwkcBa7-zKkinda like the look of the latter one.. its outside my price but looks nice?

author: julianhigginson
author_rank: Frequent Contributor
timestamp: June 19, 2018, 03:03:16 am
content: I've given away an unwanted scope before.... yeah, maybe I could have put it on ebay for $50, but what had happened was it was just sitting around collecting dust because I couldn't be bothered dealing with getting rid of it via ebay.... Also knowing it was going to someone who was interested to use it was a good feeling.Getting free old stuff is just a matter of asking at the right place and the right time when someone has something to offload.Since nobody seems to have a spare old unused instrument here, it's probably worth talking alternatives.If the OP has access to a little bit of money, there is bitscope USB scope which attaches to a computer for display and control.. their smallest one is pretty good for the money.. Available at element 14, or you can buy direct from them (they are in sydney!) Now if you could afford a good standalone scope I wouldn't be recommending it at all..... it's not the most intuiative thing going (and i seem to remember there was some wonky stuff going on with the software trying to minimise the reality of DC offsets when I last tried using one) but for a very tight budget it would do the job of looking at pretty much everything the OP has mentioned working on with 2 scope channels, a couple of logic channels, and even a basic waveform generator, and decent display size due to being a PC based instrument.http://bitscope.com/product/BS05/