Oscilloscope - are these "practical"?

[dave]

My old oscilloscope has packed up and I'm looking for a replacement. It's only for audio work so 20Mhz bandwirdh is fine. Anyone have any optinions of something like this...

on bench space if nothing else - but it does look rather a small thing. Guess I'm used to a "real" cro :-) ta.

[Phil Addison]

I hadn't seen that one before, it looks well made but very small display. Have you considered the Pico range; these use your PC as display and I imagine more versatile in the long run?

[Another Dave]

If it's only for audio frequencies have you thought of using you PC's soundcard and free Oscilloscope software; e.g.

if you've already rejected this.

Another Dave

[Mathew Newton]

Mathew

[Dave Plowman (News)]

Saves on bench space if nothing else - but it does look rather a small

I notice is doesn't give any dimensions, but looks to be little bigger than an MP3 player. I'd say that too small for serious use. Of course if it's something you carry everywhere with you the size could be an advantage - but not for bench use.

[Martin Brown]

>If you get one I'd be interested to know how it goes. Picoscope might also be worth considering.

if you usually have a pC to hand.

Or Daqarta which does something similar at audio frequencies and will do realtime spectrum analysis as well.

somewhat more band limited but potentially useful.

[Nick Odell]

>

IAN the OP but thanks from me anyway! I was only thinking the other day that I ought to have a 'scope and sig gen for the very rare occasions that more complicated electric guitar problems come my way but that the cost doesn't really justify it. The soundcard scope on the other hand...

Thanks again,

Nick

[Bob Minchin]

>> Saves on bench space if nothing else - but it does look rather a small

apart from Dimension: 98 * 60 * 14.5 Weight: 80g (without battery)

Depends if you want an indication of signal activity or toreally dig into fast rise time problems on your audio signals. Remember being all digital means you will only see a mathematicians version of your analogue signal re-created from samples. If storage is useful to you then you get a lot for your money but it is very small. Maybe for similar money you could get a decent secondhand CRO. They are not really in the same league so difficult to compare.

Bob

[Peter Crosland]

>>>> Saves on bench space if nothing else - but it does look rather a small

Don't forget to add 25% to the price for import duty plus VAT on the total including carriage.

Regards from

Peter Crosland

[Peter Parry]

As the import duty on TARIC goods nomenclature code: 9030 20 91 90 Oscilloscopes and oscillographs from China or Hong Kong is zero this would seem to be an unnecessary precaution.

[The Natural Philosopher]

there's a lot or surplus audio scopes around cheap.

And yours may be fixable.

mate of mine fixes stuff

worth asking.

[Old Codger]

> Saves on bench space if nothing else - but it does look rather a small

Looks interesting. Tempted to buy one just out of curiosity. Don't see why it shouldn't work provided the small screen will meet your needs.

A review:

standard looking scopes much cheaper at the bottom of that ebay page.

[Peter Crosland]

It is still liable to 20% VAT on the cost plus carriage along with the Customs clearance fee that the carrier is entitled to charge which is still a significant amount.

Regards from

Peter Crosland

[The Night Tripper]

Here's a UK-based review of something similar, and perhaps with a little more 'provenance':

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I want to sell one of my Tek 'scopes any buy one of these when I get chance...

J^n

[Rick]

this...

> Nice. I want one, and I don't even have any use for it! ;-)

Lissajous curves until you do ?

remember them form physcis classes in school

[Another Dave]

You're welcome. I originally used this technique to monitor the outputs from a cranky model aircraft receiver. I suspect the pulses were squarer in reality than they appeared on the scope. It did the job and cost nothing.

I don't know what voltages you're dealing with but usually you need a voltage divider circuit to drop the voltage to below 0.5V or so or you may damage the sound card. Drop the voltage more than you need to start with; you can always up the gain.

Another Dave

[Theo Markettos]

interesting... nice they provide the schematic and source code. There's more info on it here (translated from Chinese) ?f=4Note that if it has the claimed 72Msps, that doesn't translate into 72MHz frequency response. By Nyquist it can see signals at max 36MHz, but you're down to 18MHz (4 samples per cycle) at least to be able to see anything useful. It also depends if there's any filtering on the input below 36MHz (there's some on the schematic, but I haven't calculated the filter parameters).

This thread discussed the bandwidth of the SeeedStudio version, which seems to be about 10MHz due to parasitics:

fact that forum: to be an English version of the Chinese forum above. Probably worth a read.

Theo

[geoff]

How much smaller than a normal scope screen @3" x 4" ?

not a lot

[Peter Parry]

A lot less than when incorrect import duty is added. Where did you get your 25% import duty from?

[Gib Bogle]

Looks like a great tool! I haven't had a scope or signal generator for decades, but I'd like to give my audio amp a once-over. It's a pity the laptop mike will not be good enough to check out the speakers.