Buying an Oscilloscope

[masosi]

Hey everyone,

I'm finally going to buy myself a PC based oscilloscope and wanted peoples' opinions before I spend a few hundred dollars on something that may not perform. I will be using it for PIC's running at 4-20MHz, serial coms from pic to pc, logic, pwm etc. as well as learning a bit more about power supplies and noise in circuits.

I think i've narrowed it down to two:
DSO-2090 USB - AU$349.95
http://www.darkwire.com.au/html/dso-2090_usb.html
Max. sample rate Realtime sampling: 100MS/s
Bandwidth 40MHz(-3dB), Single shot bandwidth:40MHz

- or -

DSO-2150 USB - AU$419.95
http://www.darkwire.com.au/html/dso-2150_usb.html
Max. sample rate Realtime sampling: 150MS/s
Bandwidth 60MHz(-3dB), Single shot bandwidth: 60MHz


2 questions -
- Will these suit what I want, or has someone found something better out there?
- If so, is it worth the $70 difference for an extra 20MHz?

Thank you all.
Tom.

[Jerson]

Have you looked at the velleman range? I currently have a product using the PCSU1000 from them. http://www.vellemanusa.com/us/enu/product/view/?id=522377

[masosi]

PCSU1000. http://www.vellemanusa.com/us/enu/product/view/?id=522377

Thanks Jerson.

Can someone briefly explain what the spectrum analysis part is for please? Is this really useful for hobby electronics?

[falingtrea]

Here are some o'scopes with built in display and USB for scope capture.

http://www.saelig.com/miva/merchant.mvc?Screen=CTGY&Category_Code=PSBEB100

When I get enough cash together, I am seriously looking at one of these units.

[masosi]

Thanks, more options!
:)

[boroko]

I have a Tek bench scope that does wonderful things as far as seeing very small details of anything that I have had the need to see, but it can't decode data streams. Ebay purchase, needs a tune-up.

I have a Velleman HPS40 (http://www.vellemanusa.com/us/enu/product/view/?id=351409) hand held and it is nice for portable work. Single channel makes it a bit limited, and it does like to feed on batteries if you don't have external power, but I DO like it. Again. this is for signal viewing, not data stream decoding.

I had some advise from a well known magazine author and he loves his Clever Scope (http://www.cleverscope.com/products/cs328a.php). At the time, I couldn't afford it, but wanted the ability to decode data streams, I tried a Saleae Logic (http://www.saleae.com/logic/) pod for the data work and I love it @ $149. The 5 vdc input makes it limited for signal level problems, but since I already have a analog scope to see the electrical signals, the USB pod does a lot of work for me.

Hope that helps
Bo

[-Dan-]

Are there any downsides to a pc based oscilloscope as opossed to a benchtop oscilloscope?

[fowardbias]

I have been looking at the Bit Scope products. The price is a bit high and doesn't reflect the changing Euro. I am unsure about the quality of the Asian brands, although the specifications look good. Good luck.

[Byte_Butcher]

Are there any downsides to a pc based oscilloscope as opossed to a benchtop oscilloscope?

Yes. I borrowed one from a friend last year and didn't like it...
The scope was fine, (don't remember what brand), but I HATED having my PC tied up to use the scope.

Usually when I NEED a scope, my PC is busy. I've got a window open with schematics, a window open with board layout, one or more windows open with data sheets, and maybe MicroCode studio open as well. The LAST thing I want is something else competing for screen space on my monitor.
Maybe if I had a dedicated PC or dual monitors on my PC it would be fine, but with my computer and work habits I *much* prefer a stand alone scope.

There's also the issue of portability. With a laptop I guess it's no big deal, but with a desktop computer it doesn't make for a very portable scope.

Just my opinion and personal preference. Yours may be different...

[masosi]

I tried a Saleae Logic (http://www.saleae.com/logic/) pod for the data work and I love it @ $149

That looks awsome!

[boroko]

masosi:

Just so that I haven't mislead you, the Logic pod only deals with logic (read: 0-5 vdc) levels. It does it very fast, and you can catch spikes, but it is not designed for signal analysis in the traditional way. It only displays ON or OFF levels based on the 5 v logic that it sees.

For instance, if you want to watch RS232 comm, you have to tap the logic signals before the MAX232 so that you are only working within it's voltage limits. There are warnings about levels over 5 vdc. You could use a voltage divider if needed, but you are treading in thin air if you forget.

If used within it's design, it solves the problem of seeing what the data pattern is. You set up a decode criteria and it shows what it understands the capture to be. It fills the gap for me so that I didn't have to spend a lot on a new scope.

Just wanted to be clear.

Bo

[masosi]

It fills the gap for me so that I didn't have to spend a lot on a new scope.

I think i've found something to cover both :)
http://www.linkinstruments.com/mso19.htm
Its a single channel Scope with Logic Analyzer and Pattern Generator. Pretty good price i reckon!