digital oscope suggestions? <500$?

I purchased an Atten 1102CAL from HK via ebay and I am very pleased with it. http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=atten+1102&_sacat=0.

Most "better analog scopes have both delayed and "other channel" trigger functions that could well have captured your event. If you set channel B to trigger on the beginning of a sequence then channel A could be triggered from any event from the channel B source. I do understand your choice and it was a good one based on your equipment available and the required task. I frequently use delayed triggering from channel B to either enhance (brighten) a trace on channel A or to simply display the event triggered from the derived channel B event... like the system clock for example. The point I guess is that because I never had the opportunity to use a GOOD Digital scope, I had to learn to use my "poor" analog scope... The real issue is that "Digital" is "sexy", most people see digital and a lot of numbers that are SLANTED to make the instrument look good while not displaying the shortcomings of the digital "guts". The issue really comes back to "What" are you really looking for... faulty code, misused code, faulty design... (typically power supplies and by-passing) or a real issue with a part that isn't performing according to your understanding of the data sheet... That was my MAJOR area of failure in design... NOT Very Carefully... READING the data sheet... or trying to "Bend" a part to do something not well covered or recommended by the part designer... Mostly I figured out a method to make them work... Because that is "Where the Rubber Meets the Road". And No one really remembers your successes But NO ONE ever forgets your failures...

Doc

Doc,

I was doing the attempts with a Tek 2235 (and a Tek 450 earlier--but that was with a film camera). The problem wasn't that the scope couldn't be set up to capture the event, for me the problem was that the event was a non-repeatable one shot, that required me to perform several measurements, including the area under the curve and several duration measurements that were dependant upon the decay rate of the curve to specify the exact end point for the duration measurement. Perhaps it was my inexperience with scopes (I am by no means an expert) however I couldn't figure a way to do that without using a photographic capture. Indeed what gave me the idea in the first place, was a write-up from one of Edgerton's minions who described doing much the same process using an old poloroid oscope camera...

Regards,

Walt

I SEE and I apologize... My comments were slightly left of center...

Doc

Not at all. For most situations your approach is the better one. Just a few situations where there are exceptions.

For most of the folks on this forum (microprocessor focused with fairly low speed analog signals) I personally think that the Rigol (purchased new) would be a better investment than a used analog scope from one of the big names. I have purchase more than one used analog scope that had significant issues, not the least of which is poor/no calibration. So I am not sure beginners (at least for this forums focus) are well served by used oscilloscopes of any kind-at least without a local Elmer they can rely on. :)

BTW, How is your seismograph project coming? I am looking forward to seeing a write-up about it.

With a good analog scope is it possible to figure out various mesurements? Since I imagine the only way to measure anything is by measuring the waveform on the screen, which would be inexact I would imagine(reminds me of how the horizontal spread on my oscope permanently is crooked, and cnt be corrected with adjustments, making the grid on the screen hard to find meaningful) also again its alot for educational reasons,(my favorite learning tool really) probably 90% of its use will be on fully funtioning glitch free circuits, or even other circuits im investigating on a board from some scrap electronic I wouldn't hve a problem with a old analog scope that worked better, im wondering which is better for my needs....

An analog scope when dealing with repetitive (typical digital signals) is very capable of performing measurements such as those in the example I provided earlier in the thread; however, while they can be used for measurements for single shot event like I described with the flash duration tests, it is more cumbersome to do so with when compared to a DSO.

Definetly think ill go with the digitl just for ease of measurement That atten branded one seems similiar to the rigol, what's the difference between those two?

My 2 cents:

I think a logic analyzer is better for digital stuff. Scope lets you look at 2 signals, logic analylzer is much better. At the same time: almost all the "design" issues seen in the forum are software oriented - and serial.print is about all that is needed. Everything else is misconnected hardware, and getting someone to actually post their design usually takes care of that.

Everything coming out of the uC is digital. Maybe some analog stuff goes on, a scope is good for that. I have a USB scope and really haven't used it since figuring out a TTL serial signal was in-active low vs high. I bought a Saleae 8 channel logic analyzer for $150 and have not used it once. http://www.saleae.com/logic16?gclid=CN2ggdXDgbICFegRNAodUj4ASA A little bit of care in the code and you can do just about anything. If you're tweaking PWM outputs, a scope could be handy for confirming things. Playing with analog inputs, scope could be handy.

The whole point of this thread so far has been the monitoring of a pin or two... not the contents of multiple outputs... perhaps shift registers... and the best tool for the job. My point is that both scopes serve different purposed and are in many ways better suited to a specific task, digital works better for digital and analog works better on analog signals. Looking as t Pure Sine Wave that I am Listening to and seeing "Stuff" that I can't hear but is clearly displayed on a cheap digital scope is somehow wrong... a Digital scope is more valuable for absolute level and time measurements both immediate and through storage. Neither task is well performed by a Logic Analyser... and you couldn't fix your stereo easily with a logic analyzer But you could use either a digital or an analog scope for that purpose.. IMO

Doc

This showed up as an ad in my inbox today, another scope option. http://www.kitsusa.net/phpstore/html/Velleman-PCSU200-USB-PC-OSCILLOSCOPE-AND-SIGNAL-GENERATOR-6431.html

Interesting the specs make it a basic audio - low RF scope... @ 12 Mhz vert 3 DB BW and 10 Mhz sweep... The Spectrum analysis would be ok to a MHz The Generator and Bode plotter are interesting too, make a GREAT setup for developing audio filters possibly to a MHz or so. The Sig gen is likely one of those new DDS chips, I own one that is good to 5 MHz and it is nice to be able to rapidly sweep a network and look at it's response. Perhaps a little pricey for a beginner but a great beginning, well equipped and really nice equipment. Great tool for an Amateur Radio enthusiast (WA7EMS) . If I worked lowband radio I would love to have it... Vellman generally makes fairly solid devices, the few I've bought worked exactly as advertised.

Doc

Yes, I think a logic analzer is a bit off what im aiming for but those that you hook up to he PC, does it require a decently fast computer? Mines like >10years old and running 98 I think, barely handles the IDE at times lol, and doesn't have usb 2.0 does have a parallel port tho

How's it handle USB? Have to read the PC system requirements for each unit, no way to generalize.

It handles pretty slow lol, other than the speed limitation odf usb1.1 it also takes about 3 to 10 seconds to recognize a usb device is connected

http://forum.arduino.cc/index.php?topic=185740.0

Where you can find some info about what I'm playing with

My $0.02:

Digital scopes, analog scopes, and logic analyzers are different tools. It's like a screwdriver, pliers, and a hammer. In a pinch, you can make them do things outside their comfort zone, but the best option is to have all three.

I do digital stuff and use my Rigol DS1102E. I love it, but do wish you could have more measurements on-screen at once. (Limited screen area.. what can you do?)

I do analog stuff and use the Rigol there too. It's clearly out of its element, and when I cross paths with a Tek, I'll snag it.

I do multi-channel digital, when the timing of events is more important than their exact waveform. The Salae 8-channel logic analyzer is a wonderful tool. It would take a powerful and expensive scope to be a decent logic analyzer, while you can get an actual LA for not much money.

OP: Get a new computer. If you can afford $3-500 for a scope you have no excuse to keep beating a 486 into submission. You can pick up a motherboard or mini pc or netbook for peanuts. ;) No USB 2.0? C'mon man, there's no good reason to keep using that thing.