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Oscilloscopes For Modern Engineers?
Every few years someone asks this community for advice on oscilloscopes. Reader dawning writes "I've just graduated with a degree in Computer Engineering (and did a Comp Sci one while I was at it) and I'm finding myself woefully under-equipped to do some great hardware projects. I'm in major need of a good oscilloscope. I'm willing to put down $2,000 for a decent one, but there are several options and they all seem so archaic and limited. I'm happy to use something that must be controlled through a PC if that gives me more measuring features. What would you, my esteemed Slashdot colleagues, get for yourself?"
I use an R7704 at home, and a 7633 at the office.
The determined Real Programmer can write Fortran programs in any language.
As for your question, who the fuck knows?
... which will also be cheap, thanks to eBay.
Digital scopes are all the same, and all crappy, until you spend a LOT of money on them. At $2000 you will not be able to buy a DSO that will be able to replace a good analog scope for serious development/troubleshooting work.
One exception: if you can stretch your budget to get a used TDS3000 or TDS3000B series scope, that would be a good way to go.
have them take the measurements for you.
itll give you great experience in The Real World.
May I suggest you get a DAQ usb card and Labview from National Instruments. Probably some of the best investments you can do. You can do many things with a DAQ card and Labview including building your own digital Oscilloscope.
Back in graduate school, my roommate and I would dumpster dive and repair broken ones. More often than not, it's a pretty simple fix.
Like: How am I going to stop some big mean mother hubbard from tearing me a structurally superfluous new behind?
You, sir, are no engineer.
Do you even lift?
These aren't the 'roids you're looking for.
Without know what frequency range, voltage range, connectivity requirements (is computer connection USB or serial port?) I cannot help you in your selection.
OTOH you can give me the $2000 and I can give you my blessing.
What you should buy depends on what you plan to do, obviously. I've used several of the korean imports (Owon, Rigol) and although the feature set on those is incredible for the price, the units themselves have strange firmware problems that can be maddening when they strike. Also, the knockoff scopes can't seem to get "Automatic" triggering correct (they only sweep 3 or 4 times a second, no matter how fast you crank up the sweep rate, and that can be annoying when you are monitoring a signal), the Tektronix scopes are much better with regard to this feature.
I'm rather fond of the low-end Tek scopes. The LCD screen is a little slow, and there's only 2 channels, but these are not huge limitations for most basic work. I use these teaching physics and intro electronics to undergraduates - they're easy to use, lightweight, and can store data through USB or pen drives. 100 MHz for about $1200, which is OK for general use.
you need two. you do.
some old analog one, 10 or 50mhz should be cheap and easy.
then some digital storage scope with pc interface. I have a semi-cheap BK 2532 that is a low end but affordable unit for home use. (noisy fan, though).
tektronics is great but at the low end (your range) they all kind of suck. they do! that's why you need analog to 'see' the wave you can't quite see on those cheap a/d converters that $2k and less buys you.
ie, don't expect much from cheap digital on analog wave viewing.
plan to get 1 of each.
--
"It is now safe to switch off your computer."
Building a Cheap Oscilloscope Using Your PC?
There are some interesting suggestions there.
I'm thinking that some of the more adventurous open hardware folks might think about working on a completely open hardware scope. I mean, what's better than being able to use open tools to build open projects?
coding is life
Got mine on ebay for a ridiculously low price... but like someone else mentioned, what you use it for is rather important.
Unless you're doing very fast microelectronics, or lots of logic analysis work requiring the triggering at certain bus addresses, this unit should serve hobby level work. It's got PC connectivity, screenshots or CSV file capture to a thumb-drive, and can be found for less than $400.
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Depending on what you are using it for it may vary. But a good answer is to buy one of those probe kits that has an AD converter and then plugs into your computer. The computer becomes the oscilloscope via software. There a lot of ups to that like logging and being able to print the output etc. Much cheaper than buying a full oscilloscope and if you plug it into a laptop it is portable.
Look up the specs for a Rigol 1052D. It's a 16 channel logic analyzer and 2 channel analog scope. It's not a bad scope and is cheap. I also have an old Tektronix TDS1012. The Tek is nice as it's a 100Mhz scope, but when doing complex digital debugging, the Rigol is very helpful.
Probably the best deal would be to get a digital radio. If you can live with ~150Ms/s (a tad slow, but hey), then a cheap thing to do would be to get a digital radio (SDR) system. Say Mercury SDR. Those things typically have a good, 16 bit 100+Ms/s ADC front end, feeding into an FPGA that can do a lot of processing goodies, with low noise, and you should be able to hook up a Tek 7k plugin as a front-end after a few tweaks (simply to get going). You can get everything for $700. You have open source software, full documentation, and you can put a lot of very interesting signal processing on the FPGA. Keeping sampler's speed limitations in mind, you can otherwise easily match performance of many lower-end spectrum analyzers, and $20k+ scopes.
There are no $2k digital scopes with any decent feature set to speak of, even second-hand ones.
If you're into tweaking analog, then a Tektronix 7k mainframe with proper plugins gives you everything you may need. Heck, you can even get a simple logic analyzer for those. With *analog* zoom, no less.
A successful API design takes a mixture of software design and pedagogy.
I am lucky enough to have a Scopemeter 199C. It rules. If you can possibly swing the cost, I'd highly recommend it. This model has remained Fluke's top of the line portable DSO for almost a decade, and the price has not changed for years. Portability is a great advantage for all sorts of applications, and the scope itself includes a full complement of great features including spectrum analysis, cross-channel math functions, and full DMM capabilities separate from the scope hardware. The computer interface and software is nice too. Probes and accessories are extremely expensive though, so keep that in mind.
I am a geek attorney, but not your geek attorney unless you've already retained me. This is not legal advice.
Why go affordable when you can get an Agilent or Yokogawa scopecorder for like ten times your budget... really get some use out of it... and get killed by your wife in the process when you have to mortgage the house and sell the car to afford it!
You know, the TI-Nspire can mimic some of the functions of an oscilloscope and is vastly cheaper.
I've a crazy Egyptian friend who teaches (He retired from engineering and decided to give something back, after making $$$ from royalties with regards to DSL modems) who wrote a paper on using the TI-Nspire to replace an oscilloscope with regard to Lissajous figures (An abridged version was published in NCTM and you can see it at http://sites.indianriverschools.org/SRHS/teachers/drhanna/Paper.pdf without paying).
I don't know what you are going to use it for, but you might consider the idea and see if it can work for you (TI-Nspire or TI-Nspire CAS) as $150 or so it is a lot better than $2000
The USB scopes are maddeningly horrible at triggering, at sample rates, and at aliasing. You're much, MUCH better off going with a stand-alone scope (LeCroy, Tektronix, Agilent) than any of the ones run by PC. LeCroy doesn't seem to provide much in the way of repair schematics, but Tektronix and Agilent are pretty good in that respect. I'd spring for one of the nicer Agilent/HP or Tektronix scopes, frankly, or even a LeCroy, but never something which is limited to being run by PC solely.
This is a bit light on the requirements, but there wasn't exactly a defined need.
So generally speaking you should form some criteria.
Number of inputs, frequency spectrum, what comparative features do you need.
Next, if you are willing to purchase something used and have it tuned/repaired there can be considerable savings. Up one level from this is a direct refurbishing company that guarantees a functional and re-tuned unit.
Now, we all enjoy new and shiny toys, but the trick is being honest with yourself.If it's going to be used for hobby grade activities then don't fall into the trap of wanting the same things you might use at the office. While I would like some of the severs I actually have at work I would not spend the several thousand it would take to actually purchase one of them.
That said I would generally avoid ebay because most refurb shops will sale you the same thing on their site without the wait.
"You should always go to other people's funerals; otherwise, they won't come to yours." -- Yogi Berra
USBee has usb-based, software-driven oscilloscopes and logic analyzers to plug up with your computer. Not exactly the old, free-standing devices, but it might work for you. The price looks about right, too.
atmega version: http://www.serasidis.gr/circuits/AVR_oscilloscope/avr_oscilloscope.htm
look around, I've seen some $50'ish kits that are AVR based and have a small graphic lcd for display.
--
"It is now safe to switch off your computer."
Much better UI than Tek, by a longshot. Far more functional.
I don't know about the $2k price range. We have a fleet of WaveRunners that run around $15k to start, but I imagine some of the UI is the same.
First, pick a realistic frequency range, decide what other stuff you care about.
Don't forget about probes, nice ones can be expensize, don't spend your budget then find out you need $500 in probes. Again, this depends on your frequency range.
Then, a good place to start is ebay, remember, old and working is the same as new and working +5lbs per decade of age. (old test equipment is heavy!)
Some of the new Agilent scopes are sweet, we've rented some at my office (esp if you pony up for the 15" LCD) personally, having one that requires a computer is a PITA.
Decent Agilents
Good luck.
Don't skimp. Get a good one, name brand (Tek, Agilent, LeCroy, etc.) at least 100 MHz bandwidth (the higher the better), 4 channels if you can afford it, some way to get data off the scope and onto a USB drive/network. Everything else is fluff and you can pay for it if you want, but I'd say the above are non-negotiable.
Don't even think about a PC-based scope. A scope is a standalone instrument, always has been, always will be.
Pay an EE to build one for you.
If I had two grand I'd buy a Lecroy WaveAce. Meanwhile I enjoy my Fluke Scopemeter.
I used to be a certified electronics calibration technician, and I've never noticed a difference between the analog and the digital.
If $2k is your budget, and not having any idea what you're going to be using it for, I highly recommend a handheld Fluke. They were just as reliable as the old analog ones, but with more features.
This is the model I'm referring to:
Fluke 125
Official Fluke 125 page
aero2600
Please stop hurting America -- Jon Stewart
I don't know about the exact designs that you have in mind, but I wouldn't want to work on anything that goes much above 10 Mhz as tolerances are so much lower and things get so much harder to design and debug.
You shouldn't need a really high sample rate, and usually 20-40 Mhz of bandwidth on 2-4 channels is plenty.
I've used two really nice digital scopes, by Agilent and by Tektronix, while in school. Both companies have entry-level models that are right in your range, around $1,100.
http://www.tek.com/products/oscilloscopes/tds1000_tds2000/
http://www.home.agilent.com/agilent/product.jspx?nid=-34250.884298.00&cc=US&lc=eng
I've also used a high-end Agilent scope that included a 20(?) channel digital logic analyzer and a 4-channel analog scope and ran visualization software on a built in intel PC running windows. :)
While this was great for some projects, most of the time it was overkill and I much preferred the "simple" Tektronix scope that didn't have to boot up windows before it was ready to go
Don't overlook "old" analog scopes. They work just as good as the latest and greates for most uses, and can be found for a lot less.
Before you buy, try to get a better understanding of your actual needs. How many channels are you actually going to capture at any given time? What's the maximum signal frequency that you'll be working with?
Before you go spend some money, take a look at some of the ham radio utilities provided for free (with the cost of interfacing hardware) on your favorite distribution. Some other hardware considerations is the ability to export waveforms to csv, png, etc. I prefer Tektronix scopes. I would even consider a leasing program with a local vendor. A function generator and programmable power supply (Agilent) with an IEEE GPIB port might be helpful in the future.
Get a job someplace that has all the toys you want to play with.
We've been using a PicoScope (from the UK) at recently and it seems to work okay. Operates through the USB port.
While not the most powerful, the oscilloscope I use the most is a DSO nano
http://www.seeedstudio.com/depot/micro-digital-storage-oscilloscopedso-nano-p-512.html
It only has one channel, and only samples up to 1MHz, but it is literally built with a cell phone chassis, so it is tiny.
I got a 40MHz analog (non-storage) Iwatsu (SS-5705) oscilloscope. I've still got two years until my BSEE, but this thing has more than sufficed for my audio-frequency hobbyist work with sound synthesis. Bad example, maybe, but I'm just saying; keep it simple!
For a good deal try Goodwill stores, their online auction site: http://www.shopgoodwill.com/listings/, they regularly have scopes there for not very much
You mentioned hardware projects, but specifically what types of measurements are you intending to do? Based on your requirements of accuracy, voltage range, signal conditioning needs, and signal frequencies, you can determine whether you in fact need to drop $2,000 on a benchtop scope or you could use data acquisition devices.
There are data acquisition devices for less than a $1,000 that cover a lot of measurement needs (up to 1 or 2 MS/s, 16 bit analog input resolution) and way more flexiblity, but without knowing your requirements, it'd be tough to recommend something.
The utility of logic analyzers in development is not to be underestimated. The logic port is an excellent, affordable USB based logic analyzer. We've used it in the production and debugging of commercial hardware for several years now.
http://www.pctestinstruments.com
As far as Scopes go, a basic Tek one will often suffice for most development work. When the Dot-Com bubble was bursting it was possible to pick them up at a good price from failing companies. Its probably still possible if you live in an area with a lot of (failing) companies.
National Instruments makes a series of nice data acquisition cards in PCI, PCIe and USB form factors. For ~$2k you can get a board with 16-bit resolution, 1.25 MS/s (split between input channels), 2-4 analog outputs (16-bit, 2.86 MS/s), 24-48 1 MHz DIOs. The DAQ drivers are pretty well documented and easy to pull into custom code plus includes basic display and data-logging software in the form of LabVIEW SignalExpress. The main reason to go for one of these over a faster sampling O-scope is the output ports and potential for device control and testing using one piece of hardware if that's something you'd be interested in.
I'm an EE who does electronics design for a living, and I've done audio, SMPS, digital, FPGA, you name it. And in each case, the "best scope to use" was different:
- For analog work, or for simple microcontroller debugging, something like a USBee will work great.
- If you're doing higher speed analog, lower-frequency RF or switching power supply design, I'm a huge fan of the Tektronix DPO series. I use a TDS3032.
- For digital work (debugging serial/parallel interfaces and whatnot) I use an old 100MHz "Mega Zoom" HP logic analyzer.
- If I'm doing a design with a big FPGA, bringing lots of extra signals to the FPGA during layout time and using something like Chipscope Pro (on Xilinx FPGAs) to watch what's going on has been extremely handy. No test equipment required!
Psh, don't go for all of those toys, get something worth your while, get a National Instruments DAQ, It'll run you alot, but if you just graduated you might be able to get an educational discount, and they've got tons of features (and are very robust/long lasting)
http://ohm.ni.com/advisors/compactdaq
regular scopes are so limited in the ways you can analyze the data, with a daq, you can input and output, analog or digital, and write it to a spreadsheet for later, or even save jpges of the waveforms, it's wayyyyy better for engineering type analysis and all sorts of other nifty things, plus they're super accurate ( for most projecty stuff )
I picked up a used Tektronix 7904 for under $100. Of course, the four probes that I needed cost rather more than the scope, but that's life. The 7904 (with the modules that I have) is a 350MHz unit -- which is great for doing radio work. This setup could easily have cost $10k new.
Buy one of these online and the shipping will kill you. You need to find someone local who wants to get rid of one.
Digital Oscilloscope DIY Kit
DSO Nano - Pocket-Sized Digital Oscilloscope
Used is the way to go in Oscilloscopes. Engineers need to be "at one with their oscilloscope" therefore they tend to be very well cared for. The gold standard in used oscilloscopes is: http://www.sphere.bc.ca/test/justscopes.html#catalog I can't say enough good things about this company, I have bought 4 different scopes from them. PM me on Reddit if you have any questions. (snarkyaardvark)
I use a Tektronix MSO 4034 at work. Around the 2k price range I would suggest looking into a few of the smaller Tektronix two channel digital scopes as they are a good value for the price. I've also used the USBee and it does a decent job but the sample rate can be an issue. The logic analyzer on the USBee is a really nice feature for analyzing serial, I2C, SPI, etc. The downside however is the sample rate and duration is limited by your RAM.
One stainless steel tongue depressor and two copper wires.
When the foot seeks the place of the head, the line is crossed. Know your place. Keep your place. Be a shoe.
I use a Tektronics TDS2014B, really nice scope, 4 channel, 100MHz bandwidth, USB interface(B on the Back for a printer? or computer(Yeah, crazy) and an A on the front for flash drives) nice software, pause/start the view is nice for serial debugging. Don't know the cost, but it's a really nice scope, thats coming from someone who used to use an old tube scope...
I never found one I liked. They all seem very limited in the kinds of probes you can use, the triggers, or the refresh/display. I'm a software guy, so it's not like I am a hardware expert looking for some obscure features.
The best I've used are the ones with ethernet where you can access the data via an AJAX enabled webserver. Then zoom, pan, etc. It's all very slick and worked fine in a non-IE browser (Firefox), this gave me some PC access so I could show others the data I've collected, take screenshots, etc without having to swap a USB drive. If you get an older scope without networking, get one with USB or CF. Having a copy of your data is pretty important, and being able to paint on a picture to describe what you see to others is vital.
Actually, there's at least company with open hardware oscilloscopes:
http://www.bitscope.net/.
coding is life
Well, just STFW.
My blog
Yeah but you'd need an extra electron microscope just to find his cock.
You can buy a refurb Tek 2465B with 4 channels and 400 MHz bandwidth for about $1300. They are easy to use, and trigger well. Of course they are analog, so it depends on how you are going to use it. For normal lab work they are great.
I know this isn't popular advice, but you might want to consider just BUILDING an 'o scope'
and by 'o scope' really I just mean a data acquisition card with, say, 100 Mbit ethernet or maybe USB 2.0 high speed as an interface. It will obviously be PC controlled with the PC able and needed to act as a display device, but I consider those advantages, not portability / modularity drawbacks.
There are plenty of cheap ADC converters out there that will do anywhere from 1 MS/s to 1 GS/s, and I suspect that if you paid around $500 or less for the ADC chip(s), buffer amp, professional probe set, you'd still have $1500 budget left for the rest. A Mini-ITX motherboard + CPU like the Zotac IonITX A-U will set you back $350 with RAM and HDD and case included in that price. Just buying a laptop or netbook for a small dedicated display / control unit would set you back $450 or less as an alternative.
Then you just need a basic ethernet or USB 2.0 control processor, and things like the LPCExpresso board or MBED unit or a Stellaris LM3S8962 evaluation board are all in the $30-$200 range or so, and of course you could just build one with a PCB layout easily enough. The only real decision is how fast you want the control processor to be and whether you're going to add a few megabytes of on board buffer RAM in which case you'd probably be looking at some ARM9/926 or whatever CPU or module with SRAM/SDRAM interfaces for buffer memory. Or just make an expansion board for the $150 beagleboard that does signal acquisition or some such thing. Or look at the other OMAP / DSP evaluation boards that have fast local ram and USB 2.0 HS, whatever.
Anyway you won't be stuck paying scope providers for "options" like PC interface software, waveform analysis, FFT modes, printing capability, or whatever since it will all be basically free software on the PC side of things, and you control the hardware.
Admittedly 40 MBy/s streaming rate over USB 2.0 isn't all that good, but it'd be good for a real time 40 MS/s at 8b/s or 20MS/s at 16b/s and anyway with say 512kBy of buffer RAM on the board you could still capture 1Gs/s for 500us sequences at 8b/s or 250us at 16b/s or so which is not bad considering how cheap it could be to make this.
If you wanted to involve a bit more engineering effort you could easily make something 2GS/s or whatever with a lot more buffer RAM, probably even using COTS CPU modules like something from logicpd or gumstix or a TI DSP/OMAP evaluation kit even some Virtex 5 FPGA eval board or whatever just with an ADC added on to the external I/O interface and using the HS USB or Gbit/s ethernet / DSP / CPU parts "as is" on the base board.
Anyway you could certainly buy an "OK" scope for $2000, but really you'd be unlikely to get something that was fast enough or good enough to keep up with a lot of stuff like RF in the 802.11 / bluetooth band, USB 2.0 or 3.0 signals, 1 Gbit ethernet, PCI express signals, DDR3 signals, or other very common sorts of signals. You'd be basically limited to a lot of older technology slow speed serial or parallel busses and low IF frequency RF stuff and generic DC / analog circuits. Seems better to accept compromises on the features now and save most of the money or at least use it to buy expandable / generic components (PC hardware) which will handily be able to be expanded to other uses and higher performance as time goes on.
I expect that after USB 3 is out a while (maybe a year or so) you'll start to see some DSPs from places like TI or FPGAs from say Xilinx with built in USB 3 interfaces and have it be easy to interface GS/s ADCs to them, at which point the only sane choice for a basic o-scope will be PC based in such a fashion.
Anyway building the data acquisition interface from modules or parts would be a fun learning project and a useful piece of test equipment. Time was when a lot of test equipment was self built by the engineer or their department; it's a good skill / project, and very cost effective. For instance if you added some DAC and RF frequency generation and such capabilities to the unit you could have a 0-3 GHz spectrum / network analyzer WAY cheaper than even used commercial gear for a few hundred added tinkering dollars.
Personally I find traditional non-storage analog scopes pretty much useless for digital stuff. Really you can only use them if you can arrange for the signal in question to output a simple pattern that repeats infinitely.
Never used an analog storage scope but from what I hear they aren't exactly great for high speed stuff either.
One exception: if you can stretch your budget to get a used TDS3000 or TDS3000B series scope, that would be a good way to go.
There is one listed on ebay buy it now right now for the original posters budget of $2000
http://cgi.ebay.com/Tektronix-TDS3014-Digital-Oscilloscope-100MHz-w-HPIB-/300450756657?cmd=ViewItem&pt=BI_Oscilloscopes&hash=item45f442b831
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
An employer. Seriously. Every piece of test equipment I've ever owned (some costing upwards of $5000 1978 dollars) was a lousy investment.
Especially when you consider that I have a lab at $WORK with scores of tools costing more than I make in a year, it's stupid to spend my own money on them.
Lacking <sarcasm> tags,
You should be able to buy a decent used Tektronix scope on ebay for $200-300, not $2000. Something in the 2200 series, or 400 series. Digital storage scope with 2 channels, A delay B horizontal, 100Mhz bandwidth.
I have a Link Instruments MSO-9212 + Logic Analyzer Pod. Works well, is fast and accurate. Software can be a little buggy at times, but the Link customer support is very good.
I've been engineering for over 30 years and in my opinion there's nothing like a good old 7000 series Tektronix scope. You can pick one up on ebay and configure it with modules to do just about anything you would want a scope to do. They're old, use some power and oh by the way...they are analog. But they are great scopes. A lot will depend on what the projects you are talking about require, but as a good general purpose scope they are great. You can get all the manuals and work on the equipment yourself. And you will see electronics build the way no one builds it anymore, including Tek. I have a complete bench full of Tek and HP gear and it serves me well for projects ranging from audio designs to the latest single chip controller applications. Good luck in your search.
I got a DPO4034 and its great. 350MHz, 4 channels, can do I2C/CAN/SPI bus decoding and Wave Inspector rules.
I still have my father's mirroscope. He purchased it sometime in the early 50's for TV repair. It hasn't been powered up for at least 25 years though...
Why would you drop $2k on a 40MHz 2-ch monochrome scope? Especially given that the USB cable for it is $167?
$2150 get you a Tek TDS2014B - 4-ch 100MHz benchtop DSO with USB access.
handheld scopes generally have fewer channels, fewer trigger types, and smaller displays.
I think software/firmware people really need at least 4-ch. You can use it to look at the signals for SPI or the USB data + clock and I2C signals plus another channel can really help in multi-master setups. Sure you could save all that stuff for the logic analyzer, but LAs are expensive and a chore to configure. Scopes are relatively straight forward and good enough for more serial signals if you get a moderately fast one (100MHz or more). Save the LAs for nasty things like big buses. Dedicated I2C, SPI and USB debuggers are worthwhile if you get serious as they are not terribly expensive ($150-300 each for low speed versions). Although if you're doing USB on a microcontroller and think you have a signal integrity or power issue a scope is your best friend!
I use a Tektronix DPO2014. It has an optional ethernet based interface that will put the total price closer to $3000 new.
Using Steven Sharple's wonderful and open source VXI11 interface for Linux (http://osam.eee.nottingham.ac.uk/vxi11/) you can control every feature of the scope and transfer data to a Linux based computer (this would be true of any other scope that implements VXI11). This allows you to use as a traditional oscilloscope and as a DAQ. I've never used a software based oscilloscope that I liked as much as the traditional ones with nobs and such.
I almost impaled myself on my slide rule when I fell off of my bench stool after reading this! Just to make sure we are on the same page, you asked where you could BUY a scope? As in something someone else made? Son, a real engineer would BUILD his own scope! You didn't see Obi Wan Kenobi looking for shops that sold light sabers off the shelf, huh? So why should you? Four years of college and two degrees, and you can't even figure out how to make your most used tool? Why should I even hire you? A scope is personal, its like a woman. You have to mold it so that it fits you like a glove. Only you know it's unique frequency curves, and little idiosyncrasies. And only you know how to coax it to give you what you need. That sir, cannot be obtained with some common trollop of a scope you can buy at Grainger.
So start raiding the parts bins, and build that sucker. Don't even show your face around here until its made.
... at http://gtalug.org/wiki/Meetings:2005-12, Peter demonstrated the virtual oscilloscope and virtual function generator applications, which are available as open source.
The hardware unit (approx 3 x 6 x 1" thick) is available at http://www.syscompdesign.com/CGR101.html
--dave
davecb@spamcop.net
If you can find one get a digital O-scope.
I did a physics lab for E&M at UCSD and the physics department works with analogue O-scopes... they were the source of all my hate that quarter, all of it.
I then heard from an engineering buddy that over in their dept. they had digital O-scopes that didn't need to be calibrated or adjusted! and they had units on the lines! The time I could have saved working with LCR's with a digital... I can only imagine!
Eat sleep die
I recently found myself needing to upgrade from my old faitful tek 465's and 475s, as parts were failing I couldn't find anymore. I got a pair of GW Instek scopes, one 2 ch and one 4 ch, the latter going to > 1ghz and costing still under $2k. They are pretty nice, actually, and also interface to computers (windows only unless you write code) a number of ways. And will save on either SD cards or thumb drives. I don't find them a step down from the tek stuff, which is way way overpriced for the same features (but probably better quality, dunno). That's new, mind you, with a warranty. I think the cheaper one was under $400 IIRC. Both work ,and both have survived things in my physics lab that fried the probes -- not so bad at all.
They have a ton of features that the older analog scopes lacked, similar to the tek stuff they are intended to compete with. FFT, no problem, go, no-go comparisons with stored waveforms, got that....autosetup to get stuff on the screen, of course, and a ton of other features I don't happen to use or need, but all the stuff you'd expect is there.
Why guess when you can know? Measure!
The difference between a 'scope that is a joy to use and one that is useless and frustrating is triggering. Good triggering is what gives you ease-of-use. You can't see it if the 'scope can't trigger on it. This is especially true when you are trying to catch a glitch.
In my experience, Tektronix 'scopes have always been easier to use because they triggered better than the competition. We got a bunch of money once and decided to buy new oscilloscopes. Since we worked for the government, we had to write up a tender so there could be a fair competition. It drove us nuts. The specifications for the other brands were as good as those of the Tek 'scopes. We had used the competing 'scopes and hated them. We had to bend like pretzels to get a specification that would ensure that we got the 'scopes we wanted. The specifications just don't do a good job of describing how usable an oscilloscope is. (ditto for spectrum analyzers)
The Tek 'scopes were bullet proof. I could throw my 'scope in the back of a station wagon, drive to the airport, hop on a rented plane, fly five hundred miles, hike up a mountain and the Tek 'scope would ALWAYS work when I got to the job site.
These days, with digital 'scopes, a good test is to throw a nasty waveform at the 'scope and press the autoset button. If you're looking at something useful, the 'scope is good. If you're looking at garbage, the 'scope is garbage.
These days, I have an ancient Tek (circa 1970) 'scope on my bench at home. It works great for most of my home projects. At work, I have access to 'scopes that will do 1 GHz. My buds at the NRC have a 'scope that does 6 GHz. Somehow all the 'scopes are Tektronix.
Since I started in the industry in 1974, Tektronix has made the best oscilloscopes. Some of their other stuff is crap IMHO but nobody else can touch their 'scopes. I'm teaching college now and we prefer to buy as cheap as possible. Whenever we've tried something other than Tek, we've regretted it. The Tek 'scopes have the advantage of being student proof!
For other test equipment, I would choose other manufacturers. HP/Agilent would be my choice for almost everything else that isn't an oscilloscope.
nt.
It is no longer uncommon to be uncommon.
Before plunking down good $$, I'd wait and see what sort of equipment is *really* needed. Scopes are a nice tool, but there are other tools like good spectrum analyzers (with waveform analysers) and other gear that can add up quickly. I'd say, let the need present itself, then invest to the need.
---- Teach Peace. It's Cheaper Than War.
I would strongly recommend a good second hand analog one like the Tektronix 465 series which are rock solid and very cheap, and a for digital a DSO such as the Rigol (who make some of Agilent's stuff) DS1052E, this is a 50MHz 1Gs/rate and beautifully manufactured. The upside of this is that is the exact same model as the 100MHz version, so with a very trivial software hack you can turn this sub $500 DSO into a $1000 100MHz version! I would then recommend a good Digital Logic Analyser, for around $400 you can get the Intronix LA1032 (I think is the model) which is possbily the best unit on the market under $1500! View the EEVBLOG's (google it) to see the problems with DLA's and DSO's. So for under $1200 you get a 100MHz new DSO, a 100MHz S/H CRO, and a 32 Channel DLA!
I found this..seems you can make one for about $40 http://www.c-sharpcorner.com/uploadfile/mgold/virtualoscilloscope08292005103442am/virtualoscilloscope.aspx
Find yourself an old/used HP54720. These are very solid scopes that can do 2 G/s. The cards are a little tricky to get, make sure to get the mega ohm vs 50 ohm cards for scope probes. You can find some of these scope for a few hundred dollars and some of them come with the right plug-ins. Very good and inexpensive oscope.
Unless you're experimenting with some really, really interesting stuff at home, I'd strongly recommend looking through eBay for some slightly used Tektronix gear. I have a TDS420A that I picked up for just over $400, and it does everything I really need. (I do wish it had a USB port for saving screenshots - I hate keeping floppies around just for the scope.) Seriously, it's a great little scope. Save some cash and put it towards other gear, like a used programmable power supply, or a function generator, or a used logic analyzer. I've picked up some awesome gear on eBay dirt cheap - the trick is just keep watching and have patience.
If you're going to build digital circuits, with many inputs (like interfacing to a micro processor), then you'll need a digital logic analyser. They don't normally have the voltage range of a standard oscilloscope but the key is that you can display many signals at once (for example, so you can see what's happening on an address and data bus. A single input scope is a bit useless because the problems usually come in the timing between address lines, the strobe, etc. It you look for add on PC cards, there are many available that will be quite good.
If your projects don't have extraordinarily high frequencies or low signal voltages, you should be able to find something acceptable for under $250 new. When my awesome Tektronix went bad because its capacitors aged out, I got a cheap dual channel, 20mHz, analog unit to fill in while I searched for a replacement, and then discovered it was perfectly adequate for everything I was doing.
So after that price point (I see some selling new, in unopened packaging, on eBay for $200) it is a matter of figuring out how you intend to use it and then increasing price by adding necessary features to meet your needs.
The quality of the probes matters as much as the features in the scope. An inexpensive scope with excellent probes is better than a featureful scope with lame probes.
http://www.madelltech.com/m1-4.html
I have a very nice, for me, rackmount 350MHz 4 channel Tek scope with some very killer plugins.
The scopes I used at work today are really beyond anything needed for home use, unless you're into some extremely expensive hobbies.
The portable scope is a 3054B; 500MHz x4 channels. (~$10k, with options) The good one is an 11GHz x2ch Lecroy ($ almost 6 digits), I made picosecond-order measurements with it today.
The differential probe was $5k each; (wasn't that what gov. spitzer paid? lol.) our newb has killed two. (4Vmax) $2k each to fix.
If you can afford it for home use, I'd recommend the Tek 3054 or a lower bandwidth cousin. They're very easy to use.
If you can get surplus scopes coming out of downsized companies, you can get a deal; that's how I got my rackmount and a stack of plugins for $130. It was a production fixture at a missle plant in the 90s. :)
Digital is great, as long as you realize the limitations; digital displays lie sometimes. If you're going to base a paper on it, use multiple measurements with different equipment. :) I've seen fresh engineers embarrassed by artifacts.
Truth isn't Truth - Guliani
Keeping in mind that an oscilloscope consists of basically three parts; data acquisition, acquisition control, and display / data capture, using the PC for the later two pieces works well. I have used and I'm currently using devices from Link Instruments (http://www.linkinstruments.com) that provide a USB connection to the control and acquisition pod and allow for a lot of display and capture options using the power of the PC. Additionally, some of these units also have an integrated logic analyzer, and sometimes the combination can be used to provide complex triggers that neither could provide alone. I've been in engineering for more than 35 years and although some of the high end units from Agilent, Tek, or LeCroy may out perform these pods (for $15K+), for most general engineering the USB units work well. Since most of us travel with our laptops,, the little module simply drops into the bag like any other accessory making sure you always have a scope around when you need it. I am not affiliated with Link in any way, other than as a satisfied customer.
The iterative approach is pretty common: buy as much as you can afford and then buy more when you can justify it. In general you'll want as much bandwidth and as many channels as budget allows. You might also try renting first if you are looking at serious kit.
This sig washed every five years whether it needs it or not!
A good O'Scope for $2,000, is about as ridiculous as a good woman from a Dive Bar. 2 G's will put you on the low end of Fluke 199 O'Scope. I suggest if you're going to be cheap, at least try to get something like an Infinium with a good calibration program, within the frequency range of the equipment you will be working on.
Older scopes were built like tanks, so you should be able to pick up a decent used one for cheap. Check out local ham radio clubs - some of the serious radio guys have scoped in their shacks and used ones come along every so often. Check out the back of magazines like Monitoring Times, Popular Communications, CQ, and Amateur Radio for classifieds, check out QRZ.com for online classifieds. Lots of options besides the 'bay, and I'd sooner trust those sellers over the ones on ebay for the most part - it's a bit more targeted.
Without stereotyping any more than necessary, and lacking any detail about the projects you have in mind, I'm going to guess that with your background (CE+CS) you're probably working more toward the digital side of things - that is, you're more likely to need the scope for debugging why your I2C transactions are failing than checking if your homebrew PLL is working. In this case, rather than a fancy scope you might be best off with an 8- or 16-channel logic analyzer that happens to include basic scope functionalities. Since the LA will ideally be sending 1 bit/channel/sample (ideally less, if the designers were clever), a PC-based device might make sense and perform reasonably well. Key things to look for here is whether the software can be set up to decode common bus protocols (RS232/SPI/I2C/SMbus/etc), or at least let you plug in your own e.g. python script to do so. Few things suck more than diagnosing a protocol bug by running your eyes and cursor over the traces going "one, zero, zero, one..." to determine that your microcontroller is occasionally misreporting the length of the bus transfer that will follow.
Caveat Emptor is not a business model.
One reason I mention these is because newer scopes, particularly the Tek 3000-series, while incredibly useful because of their size, weight, and connectivity (they have a linux-based OS that includes a webserver so you can plug one in with a cat5 and control it from your desk remotely: pure awesome!) are just about impossible to repair. Everything, *everything* is in custom silicon. On a LeCroy you can swap out the input amps if you burn one, swap out the timebase card or the A/D cards for each channel. It's like working with an old PC, as opposed to an ipod.
Also, budget for probes. Get probes rated for at least 1.5 times the scope's bandwidth: usually people ship probes that have the same bandwidth as the scope's max, but the spec on them actually means they're at something like -3dB and pretty fuzzy at that bandwidth. I got 500's for my 350mhz scope and they're beautiful. A lot of people sell broken probes and I've found, in the three I've purchased, that in every case it was a broken solderjoint where the probe cable met the board that attaches to the scope BNC. I reflowed it (no added solder for fear it'd mess with the tuning) and got three new probes for cheap.
There are people selling vintage scopes on ebay that have NIST certification, if that's important to you, but you can also get it independently certified if you need it. Newark.com has cal services, to my surprise. (They're who we use at work.)
I personally dislike Yokogawa scopes because their interface doesn't make sense to me. I can sit down at an Agilent or Tek or LeCroy and get it to do what I want pretty quickly (digital LeCroys are weird about horizontal offset) but Yokogawas I spend a lot of time reading the manual. But they're nicely engineered.
The USB scopes I've used were disappointments to me: the $ per mhz isn't competitive with a used scope, and they're typically pretty tied to the company software, which might not do what you want.
Nostalgia's not what it used to be.
I've found for most of my Computer Engineering needs that a logic analyzer is much more useful than an oscilloscope. From the same people who brought us the magnificent "Bus Pirate" I present to you the "Open Workbench Logic Sniffer" I've never actually used it but it looks like a pretty sweet device.
fun
Unless you have a personally-negotiated employment agreement, they do anyway. It's not the equipment, it's your time -- which they're paying you for.
Lacking <sarcasm> tags,
Well, the important parts can be built. I think there is even a site dedicated to flashlights or some such that sells pre-made kits. The AI only a mad man would attempt.
Get a 100 dollar disco scope and an old desktop or laptop. Works awesome. Even does u art and i2c
I'd say that a decent scope must have at least the following:
- zero hold-off time (cheap CCD-based scopes like TDS1k series take maybe a hundred sweeps a second, any scope that can do faster than 100k sweeps/s is either in $10k+ range or is analog)
- very good input overload recovery times (100ns) -- there are no production scopes AFAIK that can offer that, you need a used sampling scope/plugin for that, or you need to look at some LTC appnotes ;)
- proper antialiasing
Once you "splurge" on those, you may as well have a decent ADC to give you enough dynamic range to offer rudimentary spectrum analysis/receiver functionality.
A successful API design takes a mixture of software design and pedagogy.
I got a Tektronix TDS3014B used on Ebay for just over $2k. It's fantastic and I couldn't recommend it more.
You need to figure out whether you can deal with just 2 channels or have to have 4. Also sampling rate...
Open source scope.
http://www.bitscope.com/
Except for the part ID's.
Which don't exist.
You made that up. I've dismantled numerous pieces of test equipment, and there were no ID or serial numbers on any parts other than the chassis and the occasional oscilloscope CRT.
How do you think the manufacturers certified these things in the first place? Not by looking up magical "part IDs".
I work using scopes every day (like much of the people here), and I prefer Digital osciloscopes since you can get better presented cuantificable information (measurements) that is barely present in analog ones. Most technicians says that analog osciloscopes are better to see glitches in the waveform but i can't believe that any of them can see with the naked eye a small tinny glich on the screen, something you can easily see with a digital storage osciloscope. But keep in mind that the sample rathe SHOULD be at least 1G sample/Second. I see rigol osciloscopes with 1Gs/s but shared between channels (two channels 500Ms/s each -poor-), I used one once that the prbes cant handle 50mhz signal whitout deformation.
I tested some Usb osciloscopes, and mostly they are crappy. Nice for educational purpose but often is not serious (specially if you want to low the budget)
I love my fluke 199C it's robust, reliable, practical, etc the best it's like something erotic when you open the box, but Tektronic table models are way more practical with the use of knobs, you can tune the trigger more easily, also the automatic mode is better that the one in fluke.
I really think that with a tektronic 100mhz 1gs/s 2 or 4 channel osciloscope you are done.
Depends upon what you want to measure, especially the frequency. I would start with a search for used equipment at HSC (http://www.halted.com).
A USB Logic Analyzer might be a good fit for some tasks and it's cheap. This one seems rather
impressive for some tasks. Check out the video in the 2nd link to see how it works.
I have no affiliation, but I've come across this unit recently and it looked interesting.
http://www.sparkfun.com/commerce/product_info.php?products_id=8938
http://www.saleae.com/logic/videos/
$2000 and decent scope. That is like military intelligence. The two do not go together.
If you are rely going to do computer engineering, Get a good scope. While the USB and PC card scopes are nice, they do not have the features or performance you will need I would look for a scope with a number of good trigger modes. I would want at least 2 channels and I would prefer 4 channels. If you can afford it I would look at getting one with the built in logic analyzer.
Remember a good scope will pay for itself very quickly, An inadequate scope will cost you more in time than you will ever save.
For that money, I'd be looking at Tek 2465B or 2467 (analog), TDS (300, 400, 500) series DSO. You can find a good selection, including some calibrated with NIST traceability under that $2k limit.
If you're a C.S. person, it's likely that you are a digital person, and you will most frequently use the oscilloscope to troubleshoot digital busses. Don't skimp on the channel count, go for 4! For things like serial busses (RS-232, SPI, I2C, etc.) you will want to watch clock, tx, and rx simultaneously. For a parallel bus, you can get your clock, chip select, and a couple addy or data lines. For most problems on your board, you can get by with the scope instead of an expensive logic analyzer if the scope has enough channels. The scope is better than the logic analyzer in many ways as you can watch for issues with noise, bus contention, etc.
Every engineer has their bias, I say go for Tek! LabVIEW and DAQ are cool for repetetive measurements under automation, but there's just no substitute for a physical front panel interface with knobs and buttons when you just want to spend a couple minutes looking at a few levels.
Try to find something with Ethernet or USB. Many of the used scopes on ebay have the old 3.5" floppy, and that becomes annoying when noone in the office remembers floppy disks and you need to get a plot off the scope to send to an FAE! :)
The basic question with an oscilloscope is how much bandwidth you need. Price goes up with bandwidth. 100 MHz is around $200. 80 GHz is around $24,000.
If you want to see what a PC motherboard or a cell phone radio is really doing, it's very expensive. If you want to see what an Arduno is doing, it's not so bad.
I have one of those sitting on my bench, and I can tell you that the Agilent MSO's are awesome. You can add acquisition memory (up to 256 million points) There's nothing like being able to zoom in on 3-4 seconds of data at a decent acquisition rate to see what is going on. Look for a good used one, and then save up and upgrade the acquisition memory as you see fit later. Many scopes have a very limited amount of acquisition memory (under 1 million samples), and it really limits how much you can zoom in and analyze the data you've just taken. You'll spend lots of time wishing you had a "better picture" otherwise. Either too zoomed out to get enough detail later, or too zoomed in to have enough to see what happened. The acquisition memory is the key. 1 million data points at 100 million samples a second does not give you a very long snapshot of what happened and going down in sample rate is not always an option. Any time you have to actually make something really work where there's multiple processors communicating and bus level interfacing, and lots of stuff going on there will be that once in a day, or week, or hour that something doesnt go quite right, and the shit starts piling up, and getting late that is what you (and your fancy scope) cant afford to miss, and you sit there with an incomplete picture, go damn I wish i could zoom in, go back 100 milliseconds or a second, and see what really happened. But I guess I'll wait ANOTHER day, week, hour whatever for it to happen again, and hope I can catch it. Many times you cant set a trigger to catch this stuff reliably, and you just cant let it go if you want your stuff to work (right). Look at the MegaZoom examples on Agilent's website to see what I mean. BTW it is also second to none at displaying data, and showing you little irregularities that appear in the signal, as well as allowing you to zoom in on that portion with (quite literally) a couple flicks of the knob. It amazes my coworkers how I can pan and zoom to all of the glitches, but the scope really does all the hard work if you do it right. It literally sticks to the edges and such when it detects you stopping close to them. Excellent piece of equipment. But the acquisition memory makes it all possible!
I picked up a good used Fluke 105 scopemeter on ebay with a bunch of goodies (cables, probes, etc) for under $600. Use the rest of your dough to buy yourself a smt hot air system and a signal generator. I would stay well clear of any PC based scopes.
Aside from not spending so much, my (maybe mopre important) suggestion would be to go shopping with a reliable and portable signal generator in order to test the equipment. Do not rely on calibration signal and/or any other source the shop is offering to you for testing.
The HAMEG company makes a decent scope HM2008 for a good price. It is one of the few scopes that are real dual-mode: true analog and digital. It has the usual a analog input channels as well 4 digital inputs.
Find a model of suitable specification - see other answers for some possibilities - and then see what secondhand ones go for on Ebay. This will stretch your $2000 quite a lot further.
Exactly. It's nice to have a really high-end oscilloscope, but if you've blown all your money on that how do you buy a signal generator, or a spectrum analyser?
Incidentally, I used to repair and set up HF and VHF radios with a frequency counter, signal generator and 40MHz 'scope. It puzzles me why people think that oscilloscopes "don't work" above the frequency written on the front - they work just fine, although the accuracy drops off. If you're peaking up the filters in a VHF lowband receiver (around 80MHz) you don't need to see an accurate waveform (you rarely need that at RF anyway) or an accurate voltage. You just need to see if you've got more or less when you tweak each coil.
These days I just take them into work and use one of the venerable Marconi 2955s on them.
Perhaps the xoscope software oscilloscope is accurate enough for your need? It uses the sound card as the input device. See
http://xoscope.sourceforge.net/ for details.
I work in electronics on an older Tek TFT model with a floppy drive and a really crap webserver, the 3032B. I recently visited a supplier that had an absolutely fantastic LeCroy 4 channel TFT with USB. My god, it was night and day. Took measurements good, easy exporting, easy to use. I'd go with them anyday. Go for 4 channel, don't skimp on that. Look hard at your application - if you can get away with less sampling rate, lose that. It adds a massive bulk to the cost. On the flip side, if you skimp it and go into a field where that won't do you'll be in trouble.
If it's for educational purposes, you should get a classic analog oscilloscope such as the Tektronix 465 or 475. A digital scope interprets the analog signals that it is measuring so everything needs to be read through this digital "filter". See that staircasing of the waveform? Is it real or is it an artifact of digitization? Wanna see the actual noise floor in a circuit instead of a series of out-of-real-time snapshots? Get an analog scope. Sure, in a lab, used by an experienced and well-educated operator, a digital scope can perform amazing feats. But for learning about the real world, you can't touch a classic analog scope.
Those devices usually don't work.
If you can live with a low bandwidth, get some cheap Voltcraft. They are fairly good. Cheap Tektronix is kinda "meh", they do work, but Voltcraft has a somewhat better firmware and less noise on it's inputs. Other than that, you'll probably be able to do virtually everything you want on an old used CRT one.
Ohh and if the device has a USB Host port, it doesn't mean it can actually use USB-sticks. Most of the time it'll only support fairly small ones.
I hate to say this as a former Tektronix engineer, but you seldom need a scope, and if you do it is typically application targeted and expensive. So the general purpose scope that all self respecting EE's used to have on the lab desk is a thing of the past.
All digital work either has debuggers or with FPGAs, Chipscope Pro or other. No scope needed. And if you really need to see how the eye diagram looks with your 10GB Ethernet, the best scope may be your receiver chip. Hard to find a 40GHz scope anyway.
I actually had a Tek 2440 300MHz Digital Storage for at least a decade, but used it less and less. Became more a educational thing to show kids how AC looked. All serial interfaces are running at muli GHz speed, and RF development is more in the 5.7GHz range and higher (802.11n) Not many scope sampling at 4x or more at those frequencies.
don't cut it off www.mgmbill.org
It all depends on how great your hardware projects are.
I've never needed a scope better than 20MHz and 2 channels, but I only do toy projects.
Start your project until you find yourself needing some inspection tools.
I got some Dutch thing back plugged into a laptop in the day, Only 8 bit digital, which is crap. (Picoscope's big brother?) It was slow to work right, but they kept asking for it back to add more pullup resistors. I scoped the parallel port with a real 'scope to find nothing was going anywhere near 0V, told them, and they fixed it. Then I had it on a 380V dc Drive, the fuse blew, the inductor peaked, and blew scope, probe & laptop. Burned tracks accross the boards! The small print said something about 500v max, which is also crap :-(.
I used a cheap 20Mhz, because if you were anywhere out in industry you could believe so little of what you saw anyhow, because the leads picked up noise. I never bought Tektronix, and never regretted it. Unless you know you're going to be in low noise environments, keep your money in your pocket. Then you put it back in your car, and bounce it around until the next time you want a 'scope. Buy a well specified meter - not one of these 'scope jobs, but frequency, capacitance, etc.
The fact is if you're doing component repair on site (like I was), you're a loser these days. You're doing Yes/No tests and swapping boards. The clever stuff is done back in the lab, and leave the good 'scope there.
You don't post any specific minimal specs you need, so here what I'd want for my lab:
I've seen many intelligent discussion on avrfreaks.net about the topic Oscilloscope search on avrfreaks
Markus
I've been using a Tek TDS2014 for several years now for both analog & digital work. 4 channels, fast enough, programmable. My only real complaint is screen burn and the long startup time.
If I didn't have absolutely NOTHING to do, I wouldn't be here.
Check out Seeed Studio scopes. They sell JYE Tech scope for $54, DSO Nano for $89. Fine if you don't need high sample rate, they are limited to 5M samples/sec or 1M samples/sec respectively.
Andrew Yeomans
One place where scopes are still well used is sensors and analog electronics in general! I've
got two scopes and a spectrum analyzer for optimizing low level systems; photodiode and EEG amplifiers.
One part that is often forgotten is interfacing with real world; sensors, actuators, lights etc. There the
generic oscilloscope is very useful!
Why are you crying? Just 10 years ago you could get a Textronix to connect to your 80286. But that would run you 10-20 thousand. So your seriously bitching about 2 thousand now? Are you kidding me? I still have my Textronix 75MHz scope, I might use it to work on a Ham radio once in awhile, or a power supply, or a memory timing issue on a ratwired project. But I sure the hell ain't measuring the Clock frequency on a main board, a main board I might remind you that's mostly surface mount, and not repairable in the field. A mainboard which already has various logic analyzers available to troubleshoot. Not to mention you could replace the board now for the PRICE of a 75MHz scope.
Waaa Waaa Waaa, save your beer money up, or go build a house or two. You'll have your two grand no problem.
There are usually a couple of vendors selling surplus oscilloscopes for very little money. As always know what your looking for and ask around to see how reputable a vendor is. Most I've seen are regulars (attended the same hamfest every year), but I've seen some new guys with questionable quality gear that get really defensive if you ask them to turn it on. Walk away from these guys.
I purchased a nice 35Mhz analog scope about 5 years ago for only $50. You may not have the same luck, but it's worth a look.
These comments are my own and do not necessarily reflect the views or opinions of my employer or colleagues...
Agreed. I am no engineer, my needs are quite modest... to the point that the scope I use is one I picked up at the flea market for $15. It can't do a quarter of what what even a reasonable scope from the early 90s can do... but... as I said... my needs are quite modest, and I don't mind waiting for the tubes to warm up.
SO all in all, I am with you. For me, $200 on a scope would have been mostly wasted. (as it was I got it for $15 as a toy 15 years ago, I just recently found a need for it). Maybe
Ive used a scope (not this one) as a glorified multimeter. Thats cool if you have a scope... but... if I didn't have any tools, I wouldn't go buy a scope just because I needed to measure a voltage.
It all comes down to what your needs are.
-Steve
"I opened my eyes, and everything went dark again"
I've only ever used the kickass $15k digital oscilloscopes that my school had, so I can't comment on low end ones, but it sounds like other posters are less than impressed.
But you're thinking too small here. You're not going to do much with just an oscilloscope. You're soon probably going to want a multi-output adjustable power supply -- makes life a lot easier when you're playing around with a chip and the couple of analog circuits that it needs to interface with the outside world. If you're going to be playing with analong circuits that need an oscilloscope, that'll soon morph into the need for a function generator. And wouldn't life be a lot easier with a logic analyzer for observing the inputs/outputs of those digital components? Maybe a frequency counter can save time taking measurements or can count some event for you. Eventually it just morphs into a home lab.
I would (and did while I was in school, in fact) go to e-bay and try to build a home lab with that $2000. New test equipment is ridiculously expensive, but you can get older pieces that still work just fine for much less -- the above items + an analog oscilloscope can be easily had for $2k.
A brand new $400 analog scope from Fry's is shit compared to my probably '80s vintage Tektronix scope that I bought from somebody for $90. Got a triple output adjustable power supply for $30 (needed a bit of repair work, but manuals for old stuff frequently come with schematics), 90s vintage logic analyzer for $150, frequency counter for $90, function generator for $100. It sounds like you're less budget constrained than I was at the time, so you could probably do a lot better here.
Yes, I agree too to this statement. I'm doing fancy hardware design has hobby designer with 6 layer boards, tiny SMD components and 7mil wires. Scope is needed to bring up a new hardware. But for this you can buy one from the cheap ones of LeCroy, Tekktronix or others. If you are planning to use high speed buses like PCI or others then you would need better equipment which are normally not affordable for hobbiest.
I also agree that an protocol analyzer is a must to have like usbee or others to analyze SPI, UART, I2C etc.
Those are the buses which a hobbiest are normally use.
I have a mixed scope at home which I bought for half price from Agilent years ago.
When I need a better scope then I take the one from my company.
Try to speed the money in other tools like good solder station, rework station, reflow ofen etc.
The following measurement equipment is a must to have.
- Scope At least 100MHz with good trigger fuctions
- Multimeter (at least two) Agilent or Fluke got really good ones
- Bus Analyzer. Various from 150$ to thousands of $
Try to write down the requirements of your hardware projects.
What do I need and what can I afford.
Then you will realize what Scope is the best for you.
Good look.
Cheers
J
http://www.google.com/search?&q=sound+card+as+oscilloscope
Get yourself a nice Tek digital scope, in the lunchbox form factor. Don't waste your time with old fashioned CRTs, they cannot produce output or be controlled by a computer, and they take up a ton of space on your bench.
I've been using a TDS210 in my home lab for over 10 years, it was $1200 new, and I really like it.
Yes, a 4-channel 350 MHz scope might be nice, but the times I could not measure what I wanted with the 2-channel 60 MHz scope have been few and far between, and in those cases, I've visited friends with super expensive LeCroy scopes.
your $2k budget will get you a pretty nice new scope, or (if you are a good shopper) a super nice used scope.
If you buy new, include options! They are hard to get after the line is discontinued...
have fun!
there are 3 kinds of people:
* those who can count
* those who can't
Tektronics 765...... ebay
Go with a Rigol. I use a low-end 2 channel 100MHz Tek at work, and a 2 channel 100Mhz Rigol at home - I honestly like the Rigol much more, even though it was only a fraction of the cost. I feel with the Teks they try to make it clear that it is a low end scope.
If you have $2k to spend, you can not just get a brand new Rigol scope, but also a good bench-top power supply and perhaps an arbitrary wave form generator - everything the home CE needs to get started.
For home use, probably a USB oscilloscope is best. They generally perform as well now as legacy/obsolete Tek or HP scopes and are even cheaper new.
In the professional world, Tek has largely been displaced by Agilent's Infinium series (and this with most of the Infinium's UI tricks simply duplicated in Tek and other scopes).
In terms of "how much oscilloscope" is needed, probably the best document to systematically determine this is from Agilent as their app notes (warning all PDF):
AN 1606 oscilloscope fundamentals - http://cp.literature.agilent.com/litweb/pdf/5989-8064EN.pdf
8 Ways 1 - http://cp.literature.agilent.com/litweb/pdf/5989-6387EN.pdf
8 More Ways 2 - http://cp.literature.agilent.com/litweb/pdf/5968-8756E.pdf
5th Harmonic... - http://cp.literature.agilent.com/litweb/pdf/5990-3600EN.pdf
I've used many, but my favorite scope right now is an HP 54502A that I bought off eBay and repaired. (bootstrapping repair using another HP scope whose tube is reaching end of life and had to be used in a very dark room!) It took a little while to get used to digital scopes from analog, but I find it very hard to go back now. I have an open source Logic Analyser as well, which cost me all of $50; the combination of the two is terrific - especially now I have sync out from the LA to the scope ..
As a CompSci student I am quite content with my no-name digital 2 channel 20MHz scope I got for a few bucks several years ago. I just use it to debug some low speed analog and digital circuits and it works alright for me. If I were you I'd hold off on buying an "expensive" scope and see what you really need for the stuff you do at home. Normally one will not need all the fancy stuff at home that one may need at work. And bear in mind spectrum and logic analyzers are also very useful for the hobbyist (I assume that's what you are when you're at home unless you plan on starting a small business). When in doubt: Buy just a scope and go for a good, but inexpensive, one at the moment. If you earn lots of cash and develop strange new hobbies which require high-end equipment you can always sell what you have to someone who is in school or just graduated.
I've been a LabVIEW programmer for close to 10 years. I have also been a C and C++ programmer for quite a long time now. I did large projects using both, sometimes using both in the same project. I can call myself a qualified programmer using both languages.
It is perfectly possible to create very large applications, using multi threading and proper design patterns. However, just like you had to spend years learning to write powerful and correct C++, you need quite some time to learn to program LabVIEW correctly.
Once you can do that, writing test and measurement applications can be as efficient or even better than with text based languages. I have the confidence to say that I wrote large data acquisition systems that performed well with very large datasets and high acquisition speeds.
But you have to understand data flow programming, and that is not something you acquire easily, just like you probably sucked at your first text based language projects.
Don't blame the tools for your failure to use them properly.
Computer engineering is electrical engineering with a computer science portion dumb ass. Many schools teach them as dual degrees since the course work so heavily overlaps. The only difference is electrical engineers aren't prepared to cope with the modern-day electronics that rely so heavily in microcontrollers and embedded programming. Suggesting a CE is not an engineer shows how clueless you are about the field, but I'm guessing you're probably just another old, has-been EE that has been replaced by a 20-something CE.
And why would anyone want an analog scope, when quality digital storage scopes can be had for not much more, yet with vastly more functionality, especially for dealing with mostly digital circuits? Again, old, fuddy-duddy, has-been.
Welcome to 2010.
I'm willing to put down $2,000 for a decent one, but there are several options and they all seem so archaic and limited. I'm happy to use something that must be controlled through a PC if that gives me more measuring features.
For $2k, you're probably stuck with "archaic and limited" scopes. That being said, depending on what you want to do check these out:
This one ranges from a few hundred to about $1500. In my limited experience with it I wasn't impressed but also didn't spend a lot of time figuring stuff out.
http://www.bitscope.com/
This one's a digital logic analyzer only but it's $150, will analyze SPI, I2C, and asynchronous serial for you. I've found it very useful.
http://www.saleae.com/logic/
For about $100 you can get this lil thing: http://www.pdamusician.com/dpscope/ works fine for hobbyists .. your needs might be different.
They have an article about it on: http://www.instructables.com/ ,too
"There are 11 kinds of people: those who know binary, those who don't, and those who could not care less!"
The 547 is the Barry White of bench top instruments. Its muscular aluminum frame is massive, yet understated. Dual independent time bases tells the ladies you've got a light but agile touch on the trigger circuits.
Truly, this is a scope for a discerning bachelor geek. When you meet an interesting woman, casually mention you've got a type 547 back in your apartment and she's bound to fish for an invitation. Then if later she cannot, in an intimate moment, resist playing with the plug-in unit, propose marriage on the spot.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
I don't recommend buying one unless you plan on doing your own projects. If you do don't spend 2k. Just buy a Rigol 1052D its a digital scope with plenty of sampling.
I would recommend the software oscilloscope if the experiments you are doing mostly are related to the digital circuits with low voltages etc. The following book has components that you need to make your own oscilloscope using your laptop or PC serial port along with software. HTH. Lab-in-a-Box: Introductory Experiments in Electric Circuits by Robert W. Hendricks, Kathleen Meehan
Another vote for the Tektronix 7633. I got one for less that $100.
I do mostly audio and for my purposes this works perfectly.
Speaking for the silent majority of Slashtards:
* Steve Jobs doesn't make them. Therefore, you don't need them - they're not cool.
* All of the major software packages are in Windows. Again, not cool, so you don't need an oscilloscope.
* Build one yourself. You'll learn a lot about embedded Linux along the way. Then you wouldn't ask these foolish questions.
There are so many options when choosing equipment these days. I was a former test engineer, EE background, I used agilent and Tek and they were great. I also used NI and had issues with it but it worked for what I needed and that was fine. If you want to build something custom that you have to support but is specific to your application, not a bad path to very slowly walk down. If you would like something out of the box that can be used for DAQ, transient capture, fft and you can also write custom code for, the Synergy is a great product. It probably is not the cheapest solution out there but it is a flexible solution. http://www.hi-techniques.com/synergy.htm
I would recommend a used Tektronix digital scope. For simple needs up to 100MHz even at 4 channels you can find one for under $1k. If you want to go real cheap grab a TDS210. I think that was the first of the small portable digital scopes they made and without probes they can be had for $300. For a 4ch 100MHz color scope look for a TDS2014, that is what I use every day and it suits me fine for low speed designs. For a good place to find used gear check out http://www.testequity.com/ and http://www.naptech.com/
Not that Instek provides Linux support, but there is an nice free software package at http://code.google.com/p/gds2000tools/ to control GDS scopes and script measurements and obtain data via Linux.
I'm going to give you a heds up on the real world:
You need to define your aprameters. If you do not start doing that immediatly, you will be eaten alive by people twisting your etimate. i.e. sales and marketing.
What kind of 'hardware' work are you doing? What speeds are we talking about? how accurate?
The Kruger Dunning explains most post on
a 286 10 years ago? It's 2010 now, try 20 years ago. 10 years ago Pentium II was the commodity PC with Athlon really starting to catch on and K6s were rare but still around. 15 years ago most people were upgrading their 386s and 486s to Pentiums and K5s. Windows 95 came out 15 years ago, and after it came out there were not many companies making products that targeted the 286. By then it had been a "386 or better" industry for years.
But your overall point makes sense. People get upset that oscope prices aren't competitive like PCs. And that doubling in performance for the same price doesn't happen.
75MHz scope is a bit underpowered for us hobbyists. 32-bit 60MHz microcontrollers are common these days (under $2 in single unit quantities). And while only a few of them can wiggle their external I/Os at their core frequency they still have clocks to measure and debug. 100MHz micros are becoming more common now. PHYs for ethernet and USB can be a pain to debug in a hobby project without a scope to see if there is just some skew or voltage problem. Being able to see if you're getting any signal out of the port at all can tell you a lot even if the signal isn't correct enough for the other end to detect it through layers of hardware protocols and software abstraction.
What lab will reject an instrument "due to it being fixed"?!
You used a 10% resistor that seems "close enough" the original was 1%. The calibration lab is used to making "minor tweaks" but having to twist all those trimmers practically all the way is going to take forever and piss them off. On the other hand, in Moms Basement, watching a Star Trek movie marathon while calibrating a scope is considered fun, not a waste of time.
You used inductive metal film resistor which screws up the high frequency performance instead of the specified non-inductive carbon comp resistor. It'll never work above 90 MHz again. The calibration lab will throw a fit because it won't calibrate at 100 MHz. However in Moms Basement you are thrilled to own a "90 MHz scope" even if the front panel label claims its a 100 MHz scope, especially since the highest clock frequency you'll likely subject the thing to anyway is probably low double digits.
You used the totally wrong temperature comp capacitors, and trimmed the rest of the scope so it'll work fine at 70 F. Unfortunately the industrial specs say it has to be calibrated from 32 F to 125 F so it simply can't pass calibration. The calibration lab will throw a fit, although it works fine in Mom's temperature controlled Basement.
That's before you start trying to mix old Tektronix scope silver bearing solders with traditional Pb/Sn and with modern lead free. I understand old fashioned Pb/Sn solder will corrode the plating off the Tek silver solder ceramic things.
So, the other side of what you're saying is that if you use parts that meet the original specs, which is pretty easy to do, there's no problem with getting an instrument that's been "fixed" calibrated.
It's kind of common sense that you'd use parts that meet the original specs in a test instrument rather than whatever you have lying in your junk box. It's also rather easy to find out what the original specs for the parts are, as service manuals with complete parts lists are readily available.
Ha, you wouldn't be satisfied with a Ferrari. Pick up any rich guy car magazines and note the ads for Ferraris. It's astonishing how many are available with under 20k miles, yet are advertising extensive service on engines, brakes and transmissions.
Owning a Ferrari is like dating a supermodel who is bipolar and addicted to cocaine and heroin. It looks good in public and when it isn't broken, it's fun as hell to drive, but after it spends more time in the shop than on the road you can't wait to get rid of it.
I'd take only 5 Hyundai Genesis V8s in exchange for 1 Ferrari. With a 385 HP V8, it's more power than all but the most recent Ferraris and more performance than you can likely get away with using in almost any part of the US.
Totally incorrect.
Owning a modern Ferrari is like owning any other hand-built product. They don't spontaneously fall apart any more. They are more highly tuned and operate closer to the limits of the materials that they're built from than mass-market cars do. This means they require more maintenance. The upside is, driving one is a far better experience for someone who is a "car person" who enjoys the finer things. If your car is just a conveyance to get you from A to B, just buy a Toyota Corolla and call it a day.
The people who buy Ferraris sometimes drive them very hard at track days. Try doing the same in a Hyundai Genesis and you'll need the cost savings as you'll have to buy a new car at the end of each day, given the same type of driving. The fact that the Ferraris have had work done is insignificant compared to the fact that this means they're basically in the same mechanical condition as delivered from the factory. Additionally, not one of those five Hyundais is a Ferrari, so the cost savings are meaningless.
These are high-end products aimed at people who can afford them. I know people who can afford them. I remember one conversation vividly - this guy bought a one year old 911 GT3 that he bought for track days and he said he was going to get a new one this year. Basically, to him, this (very expensive to me) car was a disposable toy.
I've owned cars that develop more than 400 HP, and I can tell you, it's not enough, even on public roads when there's no traffic in front of me. I don't speed (by much, anyway) but I like to get up to speed very quickly.
Putting moderation advice in your
I've used various scopes over the years and when I went on my own about 8 years ago, bought a used analog scope. It worked OK, but when it got down to needing even simple logic analysis, it didn't hack it. At that time I bought a BitScope - low cost (used the PC for a display) and had analog and logic inputs.
It worked OK until one time I needed to 'see' the analog based on a logic trigger. That model just couldn't do it. I recently bought a Rigol DS1052D which has 2 analog channels and 16 logic inputs. It was a little pricey ($1000, I think) but it has done everything I needed.
If cost were not a factor, I'd go for one of the newer Tektronix scopes that include protocol analysis. But, if cost were not a factor, I'd probably not need a scope!
Complaining an oscope is too hard to use is like a software engineer saying C is too hard. As an EE I'd be embarrassed not to be able to use a traditional scope. It's your trade for god sake.
I'm working as an EE (among other responsibilities) and the old workhorse we use here is an Agilent 54641A (MegaZoom) 350MHz - it does reasonably well for mixed signal design (I think the cost was originally around $3-5k).
However, more recently I purchased a 'throw away' unit that we could carry out into the field for harmonic noise measurements (Hantek DSO1060 - linking from the place I bought it because the sales engineer was helpful: http://www.web-tronics.com/60haheoswidm.html). The scope is listed as a 60MHz piece of equipment and has performed well and worked well despite the conditions I've thrown at it (would you carry scope out in rain, condensing steam and chunks of partially ground corn?). The other useful feature is that it has the ability to connect to a Windows based computer for remote control as well as direct measurements from the device itself.
JGG
Im not a writer, but Im regarded by everyone in my industry as someone who knows what the hell they are talking about, and the one you want to have call when something needs to work right, so I dont care that I am not the worlds most bestest proveyor of words. If given the choice to have a mind that loved putting words together, or a mind that loved putting electronics together, Id take the mind that loved electronics. I can get my point across just fine, and do a few million things that an AC like you can only dream of, and a few million more that you can't even fathom! Besides the fact that I'm typing on my phone, it was 1am then, and I was being rushed to come to bed, I think it was better than doing nothing to contribute, or attempt to have a negative impact on the conversation, as you did. I see lots of well written stuff by people who's only real experience with a scope is looking at it on the internet, and it's quite obvious they dont have a clue how they are really used. Too bad you can't validate the content of any of those posts instead. I had 75K approved to buy my scope, so I had demo unitS from every manufacturer for 6 months sitting in my lab, and ran the shit out of every one of them on many different applications to find out what really made a scope a scope, and what each one of them was really capable of. I got to pick the one I wanted, and I am glad I got the chance to have 5 of the best pieces of test equipment in the world at once to hook up at the same time, and compare them.
Find an old used Scope from wherever. Mostly for home use you'll be good. And I recommend an OsziFox for those odd little jobs that it fits. GREAT tool for some things, crappy for others and where a normal logic probe is fine, Radio Shack still has those as well.
IIRC it was $18,500 for the base rig. A huge chunk of it was upgrading the acquisition memory to 256 million datapoints, it was a $28000+ upgrade but worth every penny. I can take 2.5 seconds of data at 100 million samples a second, or I can take 10 seconds of data at 2.5 million samples a second, and still be 10x my 250kbps bus, and I have the serial communications decoding toolbox ($8000 or so) that decodes the traces, stores the messages, triggers on anything, and displays it on the screen superimposed over the traces. You can click on a message in the output list, and it takes you zoomed to the message highlights messages shown currently on the screen etc. Very cool! The rest was on various plugins, the main one being one that allows you to pipe data into Matlab, crunch on it real-time, and display the result on the screen with the data traces (awesome!!) note: the Matlab license and packages are not included in my price either! I actually got it under a promotion Agilent had where they doubled your bandwidth for free and gave you a 1ghz B/W machine PROBES and ACCESSORIES TOO! for example for the 500mhz price! 250mhz to 500mhz etc. etc. They even honored the price nearly a year later when everything finally got approved! It was over $100k off the website by then! Excellent company to deal with! The few firmware bugs I found (expected its a complicated machine) were fixed immediately, and they kept in contact with me the whole time, and after to be sure I was happy (it was fixed). The (windows based) help menu is second to none, and it gives every detail of how various measurements and statistics it can display, so when the engineer asks "well what do you mean positive duty cycle, what thresholds does it use for that" you can generally find an IEEE spec right there, as well as the math used in equation form. For the tech using it, it will also show you how to modify the settings (even links to them) to give you whatever thresholds you want for the measurements and decodes. This is very important as you can set the machine up exactly like the interface ICs and statemachines in the devices you are testing to get accurate results on your protocol decoding, and error detection, propagation delay calculations, etc. etc. It is a very excellent piece of equipment that generates results every time I use it on something. Its hard to say that about my Tek DSO3014, or my Fluke 199C. Yeah they show you voltage VS time, but the signal is so much more than that nowadays!
For CompSci, you'll probably be looking at digital signals more often than analog. Consider getting a logic analyzer instead.
I've worked with LeCroy LogicStudio 16. It's a logic analyzer that connects to your PC over USB. It does I2C, SPI, and UART triggering & decoding, and can capture 16 channels at 500 MHz. It costs just under $1000.
They've got the full application available on their website, it'll use a simulated device as a demo. http://www.lecroy.com/logicstudio/
I must admit, im not sure how to from my phone. I try to enter and space, but it just goes to what you see when I hit preview. It is very annoying, but so is capitalization, and punctuation on the thing.
I have fuck all money and I want to test the audio frequencies and strengths of some output coils I am winding and tapping. I feel that this bare bum (I can't spell this) Osillyscope, should be adequate for my needs.
.
Voting up, Voting down - If I really gave a fuck about your approval or not, I'd come and ask you.
Are you sure you're not talking about an 8000-series scope, rather than a 6000-series one? My MSO6054A was about $8500 on eBay, new in box but about half normal retail, and Agilent was running a special where they'd enable the maximum memory (8M points, which is actually just a software option) for free.
There's definitely no way to get 256M points on this particular scope, or to pay $100,000 for one.
But yeah, firmware support from Agilent has been outstanding. The DSO/MSO6000 line is rather 'mature' at this point, and they have released updates that enable a lot of features for free (8M, waveform statistics, RS-232 lister, and tracking cursors).
Dahlmann tightly grips the knife, which he may have no idea how to use, and steps out into the plain.
We bought picoscope 5203 and is just good enough. I was able to tune antennas at 13MHz, observe transitions and even found problems before EMC compliance testing. (just improvised antenna and FFT view) I has 2 channels and one signal generator. (it works great and you can even draw custom signal) 1 Gsample/s and as claimed it can show signals up to 250Mhz We had one tektronix on test, but that thing is so hard to navigate and reading from that display is much harder compared whit mouse navigation. They have only minor problems whit their USB drivers and you sometimes have to re plug/reboot device during initialisation otherwise it works great.
Here's what you want: An old (mid 70s) Tektronix SC502 in a TM502 mainframe :) gorgeous! and puny.