Are low/lower cost USB Oscilloscope's any good?

The problem is what to do with the data. Sampling and storing data in some memory is the easy part. Gettting it from the memory onto a screen in a meaningfull way is not so easy. I'm working on one and everything is about ready except for the sampling itself.

seem

Back in those days that was even worse because fast static RAM was incredibly expensive. So, we often used lower cost RAM and staggered it. Data was written into it in a round-robin fashion, read out in a normal way one bank at a time and then pieced together by software. Or in our cases mostly by a scan converter hardware. And yes, these were realtime systems where there was very little pause between acquisitions.

"Joel Kolstad"

It is rather cute and might make a lot of sense to keep around a lab forsome quick troubleshooting, but for someone's first and only scope I reallythink the money would be better spent on a used Tek box.** What you "really think" is not of much value to anyone. Old Teks are basically boat anchors.> I wonder how much storage tubes cost to manufacture? The Q1803 wouldprobably have a lot more takers if it could freeze the trace so that itwould work for troubleshooting, e.g., non-repetitive serial communications.** Not a requirement at all for most scope users. Digital geeks have an extraordinarily narrow idea what "troubleshooting"is......... Phil

"Phil Allison"

( delete troublesome Ebay link )

Old Teks are basically boat anchors.

Digital geeks have an extraordinarily narrow idea what "troubleshooting" is.

......... Phil

You might want to start off with a real scope, I still use Tek 453 and

However, as another poster pointed out the ones at

Barry Lennox.

You're correct, I looked closely and there are some minor differences. The actual specs appear the same, though -- I'd wager they're made by the same OEM, and it's the same basic design.

The price is double, but comparing the price of anything on eBay to the pricing in a brick and morter store (especially when you have to throw in a currency conversion!) is irrelevant.

You're entitled to your opinion. :-)

Depends on how old you get... I'm not thinking the really old 465s, more like the 2000-series. (I'd say 2465B, but that costs a *lot* more than what the OP is after.)

That's a very arbitrary statement. We could both come up with lists of applications where being able to freeze the display is anything from pretty worthless to an absolute necessity, but it's a reasonable statement that -- everything else being equal -- I can't imagine anyone would *not* want to have such an ability in their scope.

For many of them, sure... but consider that these days the "high-end" digital guys are doing things like troubleshooting 10Gbps data streams, and this requires plenty of extraordinarily high-end equipment. There's a good reason why Tek's "Which oscilloscope is right for you?" page --

---Joel

"Joel Kolstad"

"Phil Allison"

Aussie DSE stores are selling the scope I referred to at half the price US eBayers are being asked to pay for the mail order one you found.

( snip more of this asinine geek's opinionated crapology)

No wonder your thinking is so narrow - with that extraordinary pointy head of yours.

LOL !

....... Phil

Hi Phil,

Correct; my point was that -- in this particular case -- the price doubling doesn't imply they're not still 99% the same scope.

Here in the U.S., PlayStation 3's that retailed for $599 were going for several thousand dollars the week after they first came out. I bet someone down in Oz even paid that much... maybe you?

You're completely out of touch with reality, then.

Well, given that I don't do much digital design these days -- other than a bit of glue logic here or there --, your argument doesn't really apply.

---Joel

"Joel Kolstad " = ASD f***ed imbecile

You and "reality" have never even visited the same universe - f*****ad.

Piss off.

........ Phil

not the same scope, it's 3lb heavier, and has buttons where the DSE one has sliders (and runs on 120V),

Phil found the exact same scope on farnell's site for three times the price. they were out of stock, (possibly inventry knows more than sales) the brand this time is "CALTEK",

Farnell have another one: brand "DIGIMESS", even more expensive, but the only images for it are a blurry catalogue photo (pdf page) and the line art in manual (pdf), it looks like the same scope to me.

how easy is it to get parts for those old Teks?

the published schematic is slightly different though.

"Which oscilloscope is rigth for your pocket" maybe ? :)

Here is good one as a price/performance if you like to use your laptop.

But i'm searcing for a PCMCIA PC scope, do you know any ?

greetings, Vasile

What you want for starters is a proper analog scope. A 20MHz dual trace model is a basic starting point, or even the 10MHz single channel Phil pointed out. You can get cheap 2nd hand scopes on eBay and surplus gear sellers.

DON'T muck around with probing the mains unless you know exactly what you are doing. If you want to do it *safely* you need a proper high voltage differential isolating probe, and these are not cheap.

x10 probes are used for probing higher speed signals. In most normal cases you would use a x10 probe.

If you want to capture weaveform (for example, analysing a serial digital signal) then you need either a digital stoage scope (DSO), or a PC based one. In any case, you should get a real analog oscilloscope as well for general purpose use.

With DSO's, memory depth and sample rate are the top two requirements. The more the better.

If you really want to work on high voltage gear, you MUST get a proper differential probe. Anything else mixed with lack of experience will either kill you or your equipment.

Dave :)

Bog, reminds me of when my boss wanted me to build a digitizing 'scope. It was about the time the early 6-bit and 8-bit flash converters first hit the market. Doing the design was not the problem, i even could get the parts i wanted; getting the hours to actually build it was. It turned out, of the available personnel only i had the necessary combination of expertise to do the various tasks required to build a useful unit. (yes i was both tech and engineer) and management decided that my time was too valuable elsewhere to complete the project. You are invited to design working pre-trigger recording at near logic limit speed as well. (at the time 20 MSPS, today, about 6 GSPS)

And, sometimes it gets built in house due to politics...

I was working on toll roads, and we needed a 'presence' detector, i.e. Is there a car there, or not? We had a great laser sensor from a manufacturer ($10K per unit...) but only covered about 3 feet. We needed to cover 12 feet of lane, three lanes wide, so this would use 12 units. BUT, this was to replace the only commercial unit they had found that was $100 PER LANE, so management wanted to see if we could do it.

Now, the obvious solution would be to just hook up all four sensors (they connected with just two wires for sensor line a and b) to the lane control computers, and do the combination in software. However, the lane control computers were with a different branch of the company, and their software 'assumed' they would just get a single line saying car present, or not. So, they were going to just put out the $300K for the commercial units.

So, I went to the boss, and said that I could put together a simple interface and logic board to interface with the units, and save us $150K. So, in this case, I volunteered for the job. He gave me 6 weeks to get a prototype out. I also suggested that I could add some intelligence by using programmable logic (an eprom state machine) but that would take a little longer. He gave me an additional 4 weeks to add the programmability.

I designed and built the prototype in four weeks. It was tested and heading out to the test track in 6 weeks... with three different programmable state machines!

Charlie