Christmas time , oscillioscopes and wine

[Dippy]

A quick look at that link shows how they've copied Tektronix layout and function.
If they've copied quality to the same degree then I'll get one as well.

Did anyone ever get that funny little one that was mentioned a few months back?
It looked good enough for slow digital or audio work as I remember.

 

[Andrew Cowan]

I'm definitly going to get one. A small part of me says to get the 40MHz version, but I think I'll probably go for the 25MHz one. I rarely measure anything above 5MHz, and I have my 60MHz analogue scope for anything fast.

In addition, signals suiting a DSO (eg requiring a single shot trigger) tend to be lower frequencies - anything like a 30MHz signal is very likley to be from an analogue source, therefore repetative (and suited to an analogue scope).

As for necessary analog bandwidth: audio < 25 kHz, ultrasound < 200 kHz, I2C <= 1 MHz, SPI < typically 10 MHz (most of the time < 1 MHz), infrared 38 kHz, servo motor drivers a few kHz, PWM typcally a few kHz, switch-mode power supplys < ~1 MHz, RS-232 < 115 kHz. So a ~1 MHz analog bandwidth covers most of these applications. The digital sample rate of a low-end DSO should be about 10x the analog bandwidth, i.e. >= 10 MSamples/sec in that case (higher-end scopes use more sophisticated data processing and thus can get away with only 1.5x - 3x oversampling).

Wolfgang

Andrew

 

[Dippy]

Depends on what you are designing Andrew.
For your hobby level I'd agree generally, but when you start doing more tricky things then...

But then , of course, when you move up to pro league you have to put your wallet where your mouth is.


It just struck me that, on the face of it, it looked a good spec for the levels discussed in this Forum (with a few notable exceptions). AND, just as important, that you could throw it back if it was no good.

 

[fritz42_male]

A quick look at that link shows how they've copied Tektronix layout and function.
If they've copied quality to the same degree then I'll get one as well.

Did anyone ever get that funny little one that was mentioned a few months back?
It looked good enough for slow digital or audio work as I remember.

Do you mean this one?

http://toysdownunder.com/diy-oscilloscope-kit.html

I was wondering what it was like as well.

Anyone played with the USB/PC based scopes?

 

[Dippy]

No, not that one.
And I certainly couldn't bring myself to buy a 'diagnostic tool' from a place called "Toys...whatever" - that implies a kiddy-thing.

I meant that little one in a pretty box (looked a bit like a Phillips Go! I-pod clone).
About 80 USD as I recall.

 

[Minifig666]

Are you referring to the DSO Nano? I've heard they are (concidering their size) realy useful.

 

[Dippy]

"I've heard" .... I heard the Titanic was unsinkable

Where's the impartial reveiw by an experienced 'someone' over 15?

 

[fritz42_male]

Are you implying that people under 15 are inexperienced? Isn't that a bit ageist.

Also the toysdownunder bunch are good - I've bought some stuff off them (Polulu). That DIY Scope is also sold by Sparkfun and a few others.

I'm still scanning eBay for a Perth pickup Tektronix scopy of half decent spec. Don't mind if it's old - it would match me!

 

[Dippy]

I thought saying 15 as a 'threshhold' was being blooming generous

Not sure if DS Nano. If I use your friend Google I get flash drives and other stuff.

 

[hippy]

DSO Nano

http://www.seeedstudio.com/blog/2010/07/13/the-story-of-dso-nano/

 

[Dippy]

Ah, thanks hippy. That's the one.

Oh dear, the word "awesome" appears in the review.
That makes it 0 stars score in my review
"the portability factor is AWESOME"
i.e. pocket sized.

I think it's neat and a really nice bit of design. I'm not in awe but as usual Horses For Courses.
I think my next portable will be a Fluke though.

 

[Pauldesign]

Frustrated with old school stuffs, the electronic test gadget in the below link is what i use at home (in conjunction with my desktop PC) and is pretty cool for all the right reasons. In fact, it has nearly every handy test equipment in one package; even a low end TDR meter.

For outdoors apps, i use it with my DELL mini 1012 netbook running windows 7 & and both forms a one-stop shop test and entertainment machines.

http://www.linkinstruments.com/mso19.htm.

 

[fritz42_male]

If I can't find a decent cheap 2nd hand scope locally in the next 3-4 months, I'll probably get myself a DSO Quad - the next incarnation of the Nano.

 

[Minifig666]

"Where's the impartial reveiw by an experienced 'someone' over 15?

Do I count as experienced now then? Dude, that's like totally rad, man!
I've seen a general positive view accross the Internet spectrum.

The MSO-19 linked looks like a good and cheap bit of kit. 3 things in one for the price of one!

 

[fritz42_male]

Do I count as experienced now then? Dude, that's like totally rad, man!
I've seen a general positive view accross the Internet spectrum.

The MSO-19 linked looks like a good and cheap bit of kit. 3 things in one for the price of one!

Internet Spectrum - was that an IP enabled version of the Sinclair Spectrum?




Also I'm a bit disappointed - a yorkshire man who didn't say 'Eee bah gum'

 

[Minifig666]

No, that would be cool though. I've seen a BBC Micro ping the internet though, but I think they just had a Ethernet card talk to it via serial, or something like that.

Aye, unfortunately I'm int' wrong part o' Yorksh' f' 'Eee bah gum'.

 

[Andrew Cowan]

I've just ordered the PDS5022S (plus carry case) from CPC - I'll keep you updated .

A

 

[John West]

As far as the MSO-19, I'm not especially impressed with something that bills itself as a logic state analyzer but is limited to 8 inputs.

That will work for a few things, (most PICAXE projects,) but misses a whole lot of others, leaving the user $250 poorer but still in need of a logic state analyzer that will handle all of the rest of their analysis scenarios.

A more reasonable analyzer would have at least 16 logic channels and a couple of trigger channels. A good one, 32 logic channels. A used one will set you back about as much as an MS-19, but once you've got it you have a good expectation of it working in most any situation you'll run across, instead of just a few.

 

[Dippy]

I think probably for hobbyists that 8 channels is OK.
Though, obv, more can be really useful as well as on-screen interpretation of the signal.

I would have thought that, as a project, a logic analyser was the easiest project in the world. No fast ADCing. Just logic and plonk it on a screen.
A good project for a GLCD.


And that link by Paul reminds me of the "be aware" factor with claimed sampling rates. Be ware of huge claims for "repetitive" sampling rates.


I shall await Andrew's testing with interest.
It could prove to be a bargain entry level 'scope that covers most hobbyists needs.

I can recommend, to anyone, that a reasonable quality digital scope will give you much more info for 97.65% of projects than saving a fiver and getting an analogue one (esp if it doesn't store).

And if you can afford a reputable digital one of (genuine non-repetitive) 1GS/s and more then that will cover 99.9% of all your projects you will ever do.
Where possible, get colour.
Where possible, get a big name brand.

I know these are expensive bits of kit, but I see so many projects here from serious long-term hobbyists where they struggle and post for days and weeks - and a 'scope could sort their problem (not 'issue') in 20 minutes.
I'm surprised Rev-Ed haven't started selling instruments and tools as part of their growing portfolio.

 

[eclectic]

snip

I'm surprised Rev-Ed haven't started selling instruments and tools as part of their growing portfolio.

http://www.techsupplies.co.uk/epages/Store.sf/en_GB/?ObjectPath=/Shops/Store.TechSupplies&ViewAction=DetailSearchProducts

http://www.techsupplies.co.uk/epages/Store.sf/en_GB/?ObjectPath=/Shops/Store.TechSupplies/Categories/ElectronicComponents/CircuitConstruction

http://www.techsupplies.co.uk/epages/Store.sf/en_GB/?ViewAction=View&ObjectID=3883&Page=2


Possibly more in the shop?

e

 

[Pauldesign]

I'm surprised Rev-Ed haven't started selling instruments and tools as part of their growing portfolio.

Hey, Eclectic, Dippy didn't mean tools (besides the DMM in those links), he meant instruments. I know you're kidding.

 

[Pauldesign]

I'm surprised Rev-Ed haven't started selling instruments and tools as part of their growing portfolio.

Yeah Dippy, you're absolutely right and sometimes i always wonder if Rev Edu. normally do some kind of future markets research, expansion or growth feasibility studies.

Maybe they thought the market is saturated already and they're just concern about thier PICAXEs, other passive components and handy tools just adequate for educations and the hobbyists.

When i did management courses sometime ago, i was told ideas last a life time but opportunities doesn't.

 

[hippy]

Rev-Ed does carry out market research and all the other things you'd expect a business to do, looks at what potential opportunities there are, but for all opportunities; just because one can, it doesn't automatically follow that one should !

Most companies could not compete with large concerns dedicated to stocking a huge range of components and equipment who have massive warehouses, economies of scale, high turnover and product churn and can afford to have expensive, infrequently bought items sitting on shelves until sold.

As we've seen on the forum, no matter what's available, someone will point to somewhere else which is cheaper or a cheaper alternative, and all businesses have to consider if what they stock will ever be sold or generates enough revenue to make it worthwhile stocking.

 

[hippy]

As far as the MSO-19, I'm not especially impressed with something that bills itself as a logic state analyzer but is limited to 8 inputs.

For most PICAXE users 8 channels will likely be enough. More channels are needed when looking at address and data buses in high speed micro systems but for PICAXE it's mainly monitoring I/O pins or a specific data bus.

I have a Saleae logic analyser which is only 8 channels but has been adequate for the testing we do. In fact I've only so far put four of the hook-up connectors on the leads, so have obviously only needed four channels. If watching 8 I/O and a strobe it is handy to have more than 8 channels but it's usually not that inconvenient to watch a sub-set of I/O and move the leads over to the others.

As always it's a matter of what one's prepared to pay and what one considers the absolute minimum necessary.

http://www.saleae.com/logic

 

[Dippy]

Ec.
Thanks but I was referring to slightly more sophisticated things.
I suppose some ChCh bits and pieces are a start.
I'm sure the quality is satisfactory...

Shame they didn't promote UK made stuff such as Antex but there we go. Cheap, cheap and cheaper (ignoring carbon footprint)