Oscilloscope sale

I've been looking for a digital scope, something iwith better resolution than my DPscope. It only goes down to 500nS sampling.

I saw this add today. http://www.kitsusa.net/phpstore/html/PCS500AU-VELLEMAN-50-MHZ-DIGITAL-STORAGE-OSCILLOSCOPE-FOR-PC-1369.html This scope goes down to 20nS sampling. Not sure what I'd do with it but $99 seems like a very good price. Figure add in a USB/Parallel cable for not much money, $15-25.

Or am I just gonna be disappointed that I didn't get the same thing with USB interface for $300?

No idea how fast the parallel/USB interface will be.

Could be quite a deal. Hope someone with hands on experience can let you know. I suspect the sale price is because fewer and fewer new PCs come with a parallel port any more, so these probably are not moving very well these days.

Lefty

The software is very outdated.

It's fastest sampling rate is 1ns (1Gs/s). It's analog bandwidth is 50MHz (which is where I think you're getting the 20ns from?) The selling page seems to imply the repetitive bandwidth is 1GHz, but nothing on the official data sheet (below) suggests the front-end is wider than 50MHz. 4k of memory is pretty shallow. At max sample rate that's only 4us of capture time (or 400ns/div).

http://www.vellemanusa.com/downloads/0/user/oscilloscopes_cross_reference_uk_rev1.pdf

It isn't a steal at $100 if you use it only once. With so many other scope options for just a little bit more money, I'd have a hard time buying this one.

20nS came from the spec page. I think for most things the Salleae logic analyzer is really alll that's needed.

For analog tho: 4096 is was better than DPScope's 200 Faster USB? 1.1 with Parallel port cable vs 500K.

What woluld you recommend for just a little bit more money?

When it comes to scopes, I feel a dedicated bench top unit is the best way to go.

Personally, if I spent $100 on a PC-based scope, it would quickly become a $100 paper weight. I’m even less likely to use it knowing I have to get an adapter to make it work and the deal with the potential headaches of making that adapter work each time I want to make a quick scope measurement.

Certainly I wouldn’t bother spending $300 on a USB PC-based scope when you can have Rigol or licensed Rigol’s in the $300-400 range. (Which can also be controlled by PC via USB, so I’m told.)

If you are happy with your logic analyzer and your DPscope, why add another attachment?

I was thinking a little wider bandwidth and more storage would be good. I like having something to use with my laptop, I don't need a full benchtop unit.

You can get the Rigol 2-channel 100 MHz for about $400 and the 50 MHz version for somewhere around $325. That's not a bad price in my opinion for a plenty usable DSO. It's fast and has deep memory. The built in math is pretty nice too. I believe they have a 3 year warranty.

Unless you want to play with big boy's toy's.. There are 2 real choices IMO, Rigol for a well rated bench DSO and Saelig's line of logic analyzers... AND of all the toy's n my short list I want the Saelig the most. I own a good analog scope a Tektronix 2213... No scope is any better than the person using it but using the tool best suited to the task at hand leaves no choice but the Saelig. IMO

Bob

CrossRoads: No idea how fast the parallel/USB interface will be.

That's going to be a problem but I'd worry more about the software. This is obviously old stock so the software will be old+unsupported.

I don't think I'd buy one without seeing it in action first.

Saelig appears to be a store front for other units like the Rigol?
$400 does not look too bad.
http://www.saelig.com/MFR00068/PSPC017.htm

I do have a Saleae 8-channel logic analyzer,
http://www.saleae.com/logic/
I used it recently to tune some code to make 8 MHz SPI transfers good & fast - 41 bytes in 46uS, plus some overhead (12uS) for looping thru 324 rows, which met my goal of <100uS for a row of data update.
Kinda neat having it analyze the SPI 8-bit data and showing its hex value for confirmation, and being able to measure the time of the transfer. Kinda like having one of the big Techtronics units in a little box sitting next to my laptop.

Rigol made/makes the “low end” scopes for Agilent and probably some others. I bought an DS1102C 6 or 7 years ago when nobody had heard of them. I paid a grand for it and thought it was a steal at the time. I love it, but it has developed some kind of problem with picking up noise. I’m guessing it’s from the switching PS inside. I’m thinking a cap opened or at least went high ESR. It’s weird the noise is worst on the least sensitive vertical modes. Given the number of power company brownouts, surges, etc. that we have, I really don’t blame Rigol. It’s still completely usable, just saddens me to see it. They have a new line with 8" screens that really have my interest up.

I'm with James C4S on this. A dedicated O-Scope is the best. Look around for a "Hamfest" in your area. I've seen clean Textronix 454's -> 475's going for $200. Too many 'techies' that couldn't turn one on if their life depended on it.

$100 is a pretty good price for the features this scope has. I'd not worry too much about the software. I strongly suspect they will carry support forward for the older scopes for quite a while yet. You could always give Velleman a call to confirm this one way or the other. Also, the data transfer between the scope and the PC should not be a real issue in this application.

That being said, I do have stand-alone scopes myself, although the long-term recording capability of a scope like this is an interesting feature. It might be worth the $100 for that capability alone. I know things are very different State side, but up here that is less than 3 cases of beer.

On the subject of buying an older scope, like a Tek 465 vs. one of the new 100mHz DSOs (Pick your favorite brand, they all seem very much alike for comparable models. In fact, astonishingly so.) there are reasons to have both. Nothing on the digital side of things under $10K displays a waveform like an analog scope can, and sometimes you just really need that ability. On the other hand, as beautiful a piece of equipment as the Tek 465 is, it cannot record events like a DSO can.

FWIW, I have a Tek 465 and a UNI-T UTD2102CEL. I use both all the time and the total cost for the two was under $525, so it's not an unreasonable idea to have both.

EDIT: Not sure a parallel to USB interface would work for this. There may be bit toggling going on, and that is unlikely to be supported. I tried a USB to parallel interface with my Willem-type programmer recently and it would just not work.

The scope on sale will probably only work properly with an old Win95/98 machine, so likely not a very good buy, unless you have one of those old thumpers around and still use it. There are USB-to-parallel port adapters, which it might work with a newer machine if the drivers can emulate the scope parallel port properly. Probably can only determine if this would work by buying and trying.

But what you buy depends on what you want to do. James wants and probably needs a benchtop scope that goes to 1,000,000 Ghz with 10,000,000 GByte buffers. However, for most embedded systems work, one of the small handheld devices, also sold by Venneman, would probably be 99% effective for most other people.

http://www.kitsusa.net/phpstore/html/Oscilloscopes-173-1.html

I actually like these others, especially given the sale prices, just because they would be so convenient to use, and would measure probably 90% of signals of interest. Could take it to where the embedded system is, rather than the other way around. Yesterday, I was helping a guy try to figure out why his car wouldn't start. We used a DMM, but a scope would have been handy.

http://www.kitsusa.net/phpstore/html/Velleman-PPS10-10MSS-PERSONAL-POCKET-SCOPE-1522.html

http://www.kitsusa.net/phpstore/html/VELLEMAN-HPS10-Hand-Held-Oscilloscope-1362.html