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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?
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.
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!
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.
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.
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
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.
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!
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)
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 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
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.
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.
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 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
For audio stuff non-storage scopes are fine. Because when troubleshooting audio you would typically put a repetitive test signal in (or if you are building a synthisyser make it generate one).
For microcontroller work however you really want to be able to look at a fairly complex waveform. If you try this with a traditional scope even if you can arrange for it to be repetitive (which is sometimes quite difficult) the scope is likely to keep triggering at different poitns in the waveform. So you really want a device that can take a signal hit of a waveform and store it. Analog storage scopes do exist but I haven't personally used one so can't comment on how good they are. Also you will be dealing with higher frequency signals (a PIC18F running at it's max clock speed can toggle an IO at about 5MHz, other processors can do it much faster)
From the qualifications listed in the original request I get the impression that this guy is planning to do stuff with microcontrollers etc. If he is planning to stick with pic level stuf he will probablly be able to get away with one of the cheap chinese scopes, beyond that something better is needed.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
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.
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.
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.
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.
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).
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.
You also want a digital scope in order to have a readable display when the sweep times are very short and refresh times are long, like for instance when you have the scope with a short time base and a long horizontal delay. I remember having to turn out the room lights to see the traces properly. With digital scopes, you just turn up the intensity.
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.
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.
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
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!
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
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
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 ..
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.
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 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
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/
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
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.
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.
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.