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Forum Index : Microcontroller and PC projects : and now for some’in completely different
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| robert.rozee Guru  Joined: 31/12/2012 Location: New ZealandPosts: 2294 |
oscilloscopes, in particular digital oscilloscopes. in the past i've always divided DSOs into two categories: those that are very expensive, and those that are useless. those nice agilent/hp ones with nice deep memory are absolutely magic. i used to have one sitting on my bench at work that cost us something like $40,000. it looked like an analog scope, and behaved like an analog scope, and that deep deep memory made it magic! enter the cheap chinese DSOs. they look the part, but when you start using them they give you heartache. little memory - sometimes only a few K's - leaves you often able to see what's interesting, but not quite able to get your hands on what is vital - without a great deal of tinkering to make everything happen at just the right time. i despised them. even agilent betrayed me, releasing their DSO1000 range that was a re-badged rigol. but now i see there is something new emerging: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370921295 357 only 2-channels (real scopes have 4), but 1M of memory, and a basic logic thing (not quite a real analyser) that gives you 8 or 16 digital channels. 100MHz is fine for most hobby micro-controller stuff (60MHz is not much cheaper, 200MHz is a bigger price step). for us$450 delivered i am sorely tempted. any comments on these hantek scopes that now seem to be turning up? any experiences? rob :-) |
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BobD Guru Joined: 07/12/2011 Location: AustraliaPosts: 935 |
It's been a long while since I used an oscilloscope and even then it was a Tektronix with analogue storage with a vintage somewhere in the 1970s. It was so heavy we left it on a trolley and wheeled it around. The apparent capability of these units is astounding and I could be seriously tempted. Rob, the unit you refer to is described as "Bandwidth - 100MHz" but later in the specs there is a reference to "Bandwidth Limit - 20MHz". Can anyone explain these apparent contradictions for me. Just looked at the 200MHz unit and it has the same Bandwidth Limit. If you were doing external triggering you would need to buy some extra probes. I just read a review which answered most of my questions including whether to step up to the 200MHz unit. Like the reviewer, I would look for a more local retailer than China just for the comfort factor. Trouble is that would put a lot more money on it including 10% for GST in OZ. Amazon has a nice clear picture of the unit here. Do a "Click to open expanded view" to see the big pictures. |
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9083 |
I have a DC-2GHz spectrum analyser, and it certainly is useful kit for certain things, such as checking the harmonics of FM transmitters etc, and for TV work, both analogue(now essentially gone), and digital(checking carrier levels with respect to one another or other unwanted signals in the TV band etc). It's one of those things that when you need it - you REALLY need it. As to these cheap offerings, they may well be OK - I would also be very interested in anyone's comments from those who may have one of those things..... Smoke makes things work. When the smoke gets out, it stops! |
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TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 5923 |
Much like the reviewer except my Tektronicx is a TDS220 and it cost me $3700 about 15 years ago. It is a 100MHz model and has served me well since then. Still going strong and the only 'complaint' is it takes a few minutes to transfer a screen dump to the PC. I look at the new colour screen models but hope that I am not forced to upgrade for a long time. Bandwidth limit 20 MHz is probably the same as my Tek. You have the option of full 100MHz or limited to 20MHz. Unless you are looking at high speed, the 20 MHz filters out a lot of the noise and is much easier on the eye. It is a usefull option to have. Jim VK7JH MMedit  MMBasic Help |
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| paceman Guru Joined: 07/10/2011 Location: AustraliaPosts: 1329 |
I bought a two channel Rigol 1100E 100MHz scope from Emona (the Australian distributors) Emona a couple of years ago. I think it's been a very good buy at $400. Geoff has a revue of it on his website at Geoffs Rigol revue. I agree with everything Geoff says in his review, especially the bit about the single set of controls used to adjust the two channels - that's a bit of a pain but OK when you get used to it. The same goes for a lot of the controls. There's a lot of capability in the unit but getting to it takes some getting used to. I found the screen dump was pretty sharp, but figuring how to do it wasn't easy - once you do, it is easy. Geoff mentioned at the end of his review that you could change their cheaper 50MHz unit to the 100MHz 1102E with just a software hack. I looked into that but as he said they'll probably close that loophole and yes, they have. Greg |
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| robert.rozee Guru Joined: 31/12/2012 Location: New ZealandPosts: 2294 |
one thing to note is that the 60MHz, 100MHz and 200MHz models all have the same maximum sampling rate of 1GSa/s. so at 60MHz each repetitive waveform is interpolated across 16 points, at 100MHz across 10 points, and at 200MHz just 5 points. it is literally a case of join the dots. hence my logic at highlighting the 100MHz model as being kind of the 'sweet spot'. at the maximum rated bandwidth there will be 10 dots used to define a waveform. this is a relatively 'comfortable' number which i don't feel is too small. the triggering sensitivity also seems to fall off in the 200MHz model as one goes above 200MHz. again, it is where this model, being at the leading edge, is pushing the limits of the hardware a bit further. so one can spend another $100 and go for the 200MHz model, but with diminishing returns upon the $ investment. similarly, one can save a bit by dropping the digital channels (about $100), and going for the DSO5102D version. for the sorts of thing i'd imagine myself using the scope for, i feel that the digital channels worth the expense, while the jump from 100MHz up to 200MHz (without any change in maximum sampling rate) is not quite so easily justified. now, more memory and 4 channels might be another matter... :-) rob |
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| WhiteWizzard Guru Joined: 05/04/2013 Location: United KingdomPosts: 2794 |
Here is something worth considering if you don't need a fancy scope . . . I personally find that everything I need to do (in my digital electronics world) can be accomplished by this logic analyser. It has 8 channels, up to 24MHz with 10billion samples. Uses a PC or MAC as the display & control interface; and currently has 17 different protocol analysers including: SPI, I2C, async serial, USB, CAN, 1-Wire, DMX-512 and parallel. It only costs $149 and is absolutely brilliant for debugging micro controller hardware. I use this on my 27" iMac and cannot fault it in any way. Try their free demo software - it will give you a flavour of what it can do. 
Ok, so this is probably not suitable for trouble-shooting high frequency analogue electronics but for me it has been the best servicing tool I have ever purchased. 
PS: I am NOT affiliated to this product in any way - I just think that this little beast is worth shouting about . . . For everything Micromite visit micromite.org Direct Email: whitewizzard@micromite.o |
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| Keith W. Senior Member  Joined: 09/10/2011 Location: AustraliaPosts: 118 |
I could not ignore this price and the size,the price paid by White Wizzard is already very good. I have recently purchased this unit for the indicated price from Kalex. It came with USB cable and thin colored cables with sockets both ends, no software. A 16 channel unit is also available. I downloaded the Demo? software from the Saleae web site and it is recognized and works, though not genuine Saleae unit. There are several similar units on the web. The unit consists of a 24 MHz crystal, a CY7C68013A-56 Cypress USB/Micro/Fifo, a 24C02N I2C EEProm, a LC245A 8 bit buffer and a ML6206A 3.3 volt regulator. It could be that Cypress has promoted a logic analyser application for this chip which seems to fit this application admirably? Keith W. |
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MicroBlocks Guru Joined: 12/05/2012 Location: ThailandPosts: 2209 |
I have the Saleae too. It works really easy and good. There is a new version coming soon which also has analog!! Saleae digital + analog Microblocks. Build with logic. |
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graynomad Senior Member Joined: 21/07/2010 Location: AustraliaPosts: 122 |
The new Saleaes look pretty good, they will not replace a good scope because they are too slow on the analogue part but for many things (sensors etc) they will be great, I will probably get one (I've had a Logic 8 for a couple of years, fantastic product). But if you need a scope you need a scope, personally I reckon most people working with embedded processors should have both. @Kieth, I see the "Saleae" part of the label has been cut off, that was a but rud eof them I think to actually use the Saleae name on their clone. BTW that Hantek is nowhere near as sensitive as a Rigol, 2mV/div verses 500uV/div, but then it is half the price. Rob Gray, AKA the Graynomad, www.robgray.com |
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elproducts Senior Member Joined: 19/06/2011 Location: United StatesPosts: 282 |
I was not aware of that one but it does look nice for the price. I like the split screen zoom in on waveform feature. The logic analyzer is also a nice two in one feature. I have an OWON cheapy but it works well. I have been looking to upgrade though and this HANTEK looks like a nice option. I'd prefer to find a USA reseller though so I can get it quicker and have someone I can call with questions/issues. www.elproducts.com |
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| elproducts Senior Member Joined: 19/06/2011 Location: United StatesPosts: 282 |
If you don't need the logic analyzer check out this one: http://www.circuitspecialists.com/dso5202b.html Here is a review of it: http://blog.circuitspecialists.com/product-review-hantek-dso 5102b-100mhz-digital-storage-oscilloscope www.elproducts.com |
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| graynomad Senior Member Joined: 21/07/2010 Location: AustraliaPosts: 122 |
Another thing about many of these scopes is the sample memory, many are just 1M, some even less, the Rigol is 14M with a 56M option. BTW the link to that review (http://blog.circuitspecialists.com/product-review-hantek-dso 5102b-100mhz-digital-storage-oscilloscope) doesn't work. Rob Gray, AKA the Graynomad, www.robgray.com |
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| BobD Guru Joined: 07/12/2011 Location: AustraliaPosts: 935 |
I got one of these yesterday. It has the name Saleae on the front. If it's a clone then it's a bit cheeky but as Keith said, it's hard to ignore the price of AU$20. |
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| Frank N. Furter Guru Joined: 28/05/2012 Location: GermanyPosts: 815 |
Hi Phil, hi Keith W., thanks a lot for the hint to the analyzers. I bought a compatible one in Germany for 15€ and it works very well!
This device is a great help for me! Frank |
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