After over ten years waiting, I finally bought my first oscilloscope - Page 1
Forum section: electronics / testgear

author: Bendba
author_rank: Regular Contributor
timestamp: August 30, 2016, 02:33:54 pm
content: Hi,Just wanted to share this. After over ten years fiddling with electronics, I finally had the opportunity to buy a working oscilloscope for a good price.So yes, it is possible to buy a working oscilloscope for $50.I found a Leader LBO-505. It features pretty much everything I wanted my first scope to be, dual trace, 15mHz (claimed 20mHz buy the seller but apparently it is 15), X-Y function, tv type triggering, and it even came with what looks like a relatively new (or well maintained) probe.Here is my first test, as soon as I got home with it, I let you guess what circuit that is.If you care to comment about that piece of equipment, go ahead.

author: zapta
author_rank: Super Contributor
timestamp: August 30, 2016, 02:52:52 pm
content: Nice looking oscilloscope.

author: Mechatrommer
author_rank: Super Contributor
timestamp: August 30, 2016, 03:10:45 pm
content: i remember borrowing and using our lab osc, cro like that and no XY scale indication whatsoever, just printed 10x10 black graticule on top. the hardest part is to figure out at what X and Y offset i'm currently at. not long after, i bought digital version, the DS1052E (hacked to DS1102E), and then what i remember is i'm stuck here, and then the poisonous hoo haa of the latest DS1054Z is now flowing in my blood.

author: rsjsouza
author_rank: Super Contributor
timestamp: August 30, 2016, 03:16:06 pm
content: Quote from: Wuerstchenhund on August 30, 2016, 02:53:52 pmUnnecessary hair splitting, Wuerstchenhund...Quote from: GlowingGhoul on August 30, 2016, 03:04:27 pmRight back at you. You can't pass an opportunity to trash Wuerstchenhund.AND NOW BACK TO YOUR REGULAR PROGRAM:Quote from: Bendba on August 30, 2016, 02:33:54 pmCongratulations on your scope! I have spent about the same time before I was able to get my first oscilloscope and I know how exciting this is. I wish you years of enjoyment with your new toy, and I can tell you are already putting it to good use!

author: TAMHAN
author_rank: Frequent Contributor
timestamp: August 30, 2016, 03:20:22 pm
content: Hello,in fact, it looks like you got two probes. Believe me that you will like multichannel a lot. I can never understand why I was so stupid to make do with but one probe for so many years...

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: August 30, 2016, 03:22:21 pm
content: Quote from: rsjsouza on August 30, 2016, 03:16:06 pmNo, it's not. In fact, it's essential as a beginner to learn the correct use of units right from the beginning. This is the very basic of EE.And especially when it comes to voltage or current, mis-handling the units can have*very*drastic consequences.QuoteNo, he's my regular troll. Don't worry about him though, I already reported this posts so let the Mods deal with that.

author: helius
author_rank: Super Contributor
timestamp: August 30, 2016, 03:28:06 pm
content: Quote from: GlowingGhoul on August 30, 2016, 03:04:27 pmFaced between a straightforward (albeit punctilious) comment that was not even sarcastic, and an angry revilement that's completely off topic, I don't see much of a contest.To the OP: that scope looks to be in pretty good shape, but if it were mine I would spend some time cleaning the screen. You don't want to scratch it, so use a very soft slightly moist towel. Absolutely avoid dripping liquid around the edges, though. You can also use lens tissues, but they can't absorb heavier soil. I like the banana plug H sweep, it can be quite handy and not many scopes have it. Also, the radial ticks on the graticule are for use as a video vectorscope: with component video R-Y and B-Y on the inputs, that can be used to calibrate TVs and VCRs.

author: joeqsmith
author_rank: Super Contributor
timestamp: August 30, 2016, 04:07:52 pm
content: OP, we used Leader brand scopes where I worked at. These looked like a bit newer style than what you have. Have fun with it but I warn you, from my own personal experience, once you buy your first scope you may find your self buying another! Then another!Quote from: Wuerstchenhund on August 30, 2016, 03:22:21 pm

author: Muxr
author_rank: Super Contributor
timestamp: August 30, 2016, 04:48:38 pm
content: Looks cool.. getting your first scope is a great feeling.. the whole new world of possibilities open up.

author: tggzzz
author_rank: Super Contributor
timestamp: August 30, 2016, 05:29:22 pm
content: Quote from: Bendba on August 30, 2016, 02:33:54 pmHave fun using it safely.Don't let anyone tell you that you should have bought something "better".Youmightdecide to buy something "better" later, but that will be after you have gained a lot more knowlege of what isbeneficialtoyou!

author: Bendba
author_rank: Regular Contributor
timestamp: August 30, 2016, 10:53:34 pm
content: Hi,Thanks for all the comments. And sorry for the typo, of course, it is not a 15 mHz scope but a 1.5×10^10 mHz scope (or just use a capital "m")Quote from: TAMHAN on August 30, 2016, 03:20:22 pmI actually have three because when I won the auction for the scope last month (yes, had to wait a month between the day I won the auction and the day I brought it home, ) I immediately ordered two probes on ebay, seen I didn't expect to get one with a second hand buy.And the two channels is one of the reason it took me so long to buy my first piece of equipment, I really wanted to be able to have a reference trace on the screen for anything timing critical.Quote from: helius on August 30, 2016, 03:28:06 pmThe screen could indeed do with a bit of polishing. It's a setup I've never seen before though, the graticule isn't etched in the glass but in a piece of polycarbonate in front of it and you can slightly tilt it one way or the other to correct the alignment.And I still have everything to learn about crt tuning/calibration. But I really wanted to have the capability so I can learn it.The other reason for the X-Y function is that I want to make a ferromagnetic hysteresis curve tracer to play with magnetic core memories (got a tiny can about 1/3 cup in volume with I believe 15,000 ferrite cores in it, ) as well as making a semiconductor curve tracer.Quote from: tggzzz on August 30, 2016, 05:29:22 pmHell no, I am more than happy with it for a first buy, it is much better than the single trace scopes I've seen a lot of people buying for a starter (not saying there is anything wrong in doing so, just making the point that I'm happy with that. And if anyone tells me is not good enough for the beginner, I'm happy to give them my address so they can ship me a better one)Plus, can you really get much better for $50?

author: tggzzz
author_rank: Super Contributor
timestamp: August 31, 2016, 08:50:10 am
content: Quote from: Bendba on August 30, 2016, 10:53:34 pmA very sane attitudeQuoteYes, but you have to be lucky and wait, and maybe do a bit of repair. I got an HP1740 for £60 and a Tek 475 for £35 (the latter needed recapping). But neither of those would be more beneficial for your applications, which is the important consideration!It helps if there is a high local density of old scopes, which might not be the case in large parts of Australia!

author: Fungus
author_rank: Super Contributor
timestamp: August 31, 2016, 09:33:52 am
content: Quote from: Bendba on August 30, 2016, 10:53:34 pmThem's fighting words around here...

author: Bicurico
author_rank: Super Contributor
timestamp: August 31, 2016, 09:40:25 am
content: "After over ten years waiting, I finally bought my first oscilloscope"I would like to add some personal advise: NEVER refrain from getting or doing what you really desire! Your life span is much too short to wait 10 years to buy something as simple as an oscilloscope!Of course, you cannot buy whatever comes to your mind (I couldn't buy myself a Ferrari). But it hurts my soul that you waited 10 years to buy an oscilloscope for 50 Euro.Have fun with it nevertheless, but never keep yourself from enjoyable experiences just to save a few bucks...Regards,Vitor

author: VK5RC
author_rank: Unknown
timestamp: August 31, 2016, 12:18:32 pm
content: It looks a nice unit, I think that is a pretty good price for Australia.For a lot of test gear, I feel it is how well you know the gear, its strengths and weaknesses, and how you use it, is often more relevant than it being on the bleeding edge of technology.In my radio club the other night I was talking to a fellow about frequency accuracy, needless to say Rubidiums/ GPSDOs came up, after a few minutes one of the 'grey beards' joined the conversation and pointed out how to use the WWV time signal and a receiver to achieve the same result. The grey beard really understands the whole area and the simple tools but really well.

author: tggzzz
author_rank: Super Contributor
timestamp: August 31, 2016, 02:10:23 pm
content: Quote from: VK5RC on August 31, 2016, 12:18:32 pmVery very true.In gliding there's a contentious axiom that "there is no substitute for span". The greybeards correctly retort "Yes there is: skill. But you canbuyspan"

author: rdl
author_rank: Super Contributor
timestamp: August 31, 2016, 03:28:14 pm
content: Quote from: Bicurico on August 31, 2016, 09:40:25 amGood advice. I agree. Life is short.

author: zapta
author_rank: Super Contributor
timestamp: August 31, 2016, 04:58:20 pm
content: Quote from: Bicurico on August 31, 2016, 09:40:25 amWho knows, maybe he was paying the loan on his private jet.Different people, different life circumstances. You don't need to feel bad for him, his life may be going overall better than yours.

author: Pinkus
author_rank: Frequent Contributor
timestamp: August 31, 2016, 06:06:40 pm
content: Quote from: joeqsmith on August 30, 2016, 04:07:52 pmExactly!With all the scopes I had by now (10 if I recall correctly), I was looking after an improved replacement within a year or two as new ones were improved so much. The latest is the Keysight MSOX3024A (for almost 2 years now) and this is the first time I am not looking after anything else. I am completely satisfied with it (almost).

author: Bendba
author_rank: Regular Contributor
timestamp: August 31, 2016, 10:37:47 pm
content: Quote from: zapta on August 31, 2016, 04:58:20 pmExactly. We are probably not playing in the same league. Even though, I'm not aware of owning any jet. The only flying device I have is a tennis ball.All jokes aside, electronics is a hobby for me and so far, I haven't be able to spend lots of money in it (the tally of what I spent over the last 10 years is probably around $300) remember I'm only 26!That doesn't stop me having the possibility to experiment a lot, especially desoLdering components and testing them before using them in new circuits.I have a good collection, over 300 transistors, countless resistors, capacitors (I know what you are going to say, they are not worth reusing, especially electrolytic but out of 10 salvaged parts, usually you find one that is still up to specs and half a dozen good enough to do some filtering where frequency is not a critical factor,) I have a few vfd's, led segment display, lcd's, even a top quality oled I believe from a piece of medical equipment I got out of the scrap bin (there is an electronic device recycling facility in town, they are very kind to let me dig in their stockpile.) I even have a fair bit of ic's, from the good old 555 trough the 74xx and 4xxx to some nifty processors and microcontrollers. I also have a nice collection of tv vacuum tubes, and they are not as useless as some people think (it seams that for a lot,if it is not a 12AX7 or a 6L6 it is no good)I believe the situation gives me some advantage of some sort in the fact that I have learned to adapt to what is available.So I'll probably be fine with my $50 spending for a couple of years now, I can make a lot of new circuits, plus I have plenty of projects for more test gears, planning on making a frequency counter, curve tracers, bench power supply, signal generator, ...See, money doesn't buy you experience, it just helps getting there faster.That aside, don't worry, I live a full life, I just learned to do it on the financially "cheap" way and I'm happy about it. I don't envy any of my neighbor's TV, brand new car or any of your electronic lab, I have my own handyman business and a 8t truck parked out the front.Quote from: VK5RC on August 31, 2016, 12:18:32 pmThat is actually one thing I'm trying to work out at the moment. An oscilloscope is nice but I don't have any sort of accurate time reference at home and I believe we don't have any RF time signal transmitter in Australia. I know I can pull the time signal out of GPS signal but I'd like something simpler.Maybe I just need a big a** antenna to receive overseas time signals.Quote from: Fungus on August 31, 2016, 09:33:52 amI'll let you know when I have another $50 spend, unless I can get a discount.

author: tggzzz
author_rank: Super Contributor
timestamp: August 31, 2016, 10:59:15 pm
content: Quote from: Bendba on August 31, 2016, 10:37:47 pmActually, money can make it slower. Oftentimes the more expensive thing are more complex, and complexity always has a learning curve before you become productive. That, for a beginner, is one of the advantages of old simple analogue scopes.Besides, doing more with less is funQuoteDon't forget "atmospherics" change the propagation path and therefore the time delay between the transmitter and receiver.Once you go down the (very enjoyable) metrology rathole, you will start to distinguish between accuracy, precision, stability, repeatability, resolution, etc. The voltnuts and timenuts have that down to a fine artW.r.t. frequency, you will soon need to learn about "phase noise", which is something all radio systems have to contend with.As ever, considerwhatyou need to know andwhy- but you are already getting to grips with those considerations

author: Assafl
author_rank: Frequent Contributor
timestamp: September 01, 2016, 05:43:35 am
content: Ahhh - first scope. Love at first sight. But amour can get you in trouble... I'd say now is as good a time as any to characterize your scope.Take as many different sources that you know (or think you know) and put them up on the scope. See how it reacts. See what it does really well, what it does reasonably well - and perhaps - where it sucks. All scopes suck at some things. Even $100k Agilents.Figure out what cal buttons do - and where you should keep them anchored, and where to use alt vs. chop modes. Press every button. Check that there is no noise on the pots and fix any noisy pot or connector.It will save you later on when you try to fix artefacts that are scope created rather than DUT created....

author: zapta
author_rank: Super Contributor
timestamp: September 01, 2016, 12:01:31 pm
content: Quote from: Bendba on August 31, 2016, 10:37:47 pmI admire your attitude to life very much. We need more of you.

author: Bendba
author_rank: Regular Contributor
timestamp: September 01, 2016, 12:16:59 pm
content: Quote from: tggzzz on August 31, 2016, 10:59:15 pmI agree with that.Quote from: tggzzz on August 31, 2016, 10:59:15 pmI still have lots to learn about that. Basically, the idea is to have a reference that I know for example, gives me a tick every 1 second or 10 second, or any known duration so I can calibrate things like a frequency counter (I believe even a quartz time base needs to be tuned to a reference. Or am I wrong)It's a bit like the chook and the egg.I can't count a reference frequency if my counter's time base isn't right. And I can't tune it right if I don't have a reference.The best, easy way I can think of at the moment is the mains 50HzQuote from: Assafl on September 01, 2016, 05:43:35 amDon't worry, I'm probing away and am going to put Google at work with a ton of questions about what I can see on my screen.The first thing I've found out is that there is an awful lot of noise coming from switching power supplies in a house. And even the main itself seems to be awfully noisy when everything is turned off at home.

author: setq
author_rank: Frequent Contributor
timestamp: September 01, 2016, 12:52:26 pm
content: Nice scope.I did with a single channel 5MHz one for ten years that the triggering was borked on. Now I've got a nice 50MHz Philips one that is older than me and cost me less than a cake and coffee at Starbucks. That was borked but I learned enough with the first one to fix this one.Doing more with less and being forced to solve problems is absolutely the best way to learn stuff.

author: tggzzz
author_rank: Super Contributor
timestamp: September 01, 2016, 12:57:51 pm
content: Quote from: Bendba on September 01, 2016, 12:16:59 pmWelcome to the rathole inhabited by timenutsAll modern devices use crystals for time/frequency control, and they will bemuchmore accurate than an old analogue scope. Old analogue scopes and sig gens are based on resistors and capacitors, so 2% isn't unusual.The 50Hz isareference, suitable for old siggens, and is a good use for lissajous figures. But don't forget that it is only 50Hzon average, so mechanical and old LED clocks keep time in the long term. As I write, the UK frequency is 50.054Hz, seehttp://www.gridwatch.templar.co.uk/QuoteDon't forget that you are measuring the UUT+probe+scope combination. FFI on probes, seehttps://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/