100MHz or 200MHz DSO

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dev
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100MHz or 200MHz DSO

Post by dev » Mon Nov 06, 2017 3:49 pm

Hi,
I am looking for DSO. I am bit confused in selection between 100MHz and 200 MHz.
Now, i can work with 100MHz, which is pretty sufficient now. But there is difference of 50$ between them on Aliexpress.

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ahull
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Re: 100MHz or 200MHz DSO

Post by ahull » Mon Nov 06, 2017 4:03 pm

More MHz == more better :D .. seriously though, it all depends on what you are planning on using it for. I have a 100MHz scope in the office, and an old analog 40MHz one at home, I rarely need anything faster.

Having said that if you plan on working with modern CPUs and micro controllers and can afford something capable of better bandwidth, then it will give you a little future proofing. It will also, generally provide better resolution at lower speeds, which makes finding those little spurious glitches and dropped bits that little bit easier. If I could afford the latest Agilent all singing all dancing scope, I would have one. Sadly my hobby budget doesn't stretch to a multi GHz scope/analyser.

When you start getting in to the multiple 100MHz plus range, or even up in to the GHz, then things get a little difficult to measure any way. You need specialist probes, short wires, and a better understanding of how signals behave at these high speeds, but that is a whole different subject.

In short, if you think you will get your moneys worth out of the extra £50 spent on doubling the bandwidth, then go for it. If, on the other hand you come out in a cold sweat at the thought of wasting money (my analog scope only cost £30, second hand on eBay, but was faulty, so I had the fun of fixing it too), then save the money for other things.
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dave j
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Re: 100MHz or 200MHz DSO

Post by dave j » Mon Nov 06, 2017 4:16 pm

Check out the EEVblog forum. Some scopes are hackable - even to increase bandwidth.

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Pito
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Re: 100MHz or 200MHz DSO

Post by Pito » Mon Nov 06, 2017 4:46 pm

The diff between 100M and 200M is small. You may see it maybe at the rising/falling edges.

Code: Select all

Rise time (ns) = 0.35/Bandwidth (GHz)
The sample rate is also very important - in GigaSamples per second. And there are about 20 other important factors..
Oscope is an investment for most amateurs, you will use it for next 10y sure. Therefore buy the best you can afford.
I've been in the evaluation phase with my purchase since 2010.
The more you know about the stuff the less probability you will buy.. Especially when you start reading the eevblog :)
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dev
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Re: 100MHz or 200MHz DSO

Post by dev » Mon Nov 06, 2017 5:05 pm

yes right. More options make more confusions.

dso5102p for 100 MHz and
dso5202p for 200 MHz.

I think you are right to go with higher the version (future use).

are these models are good for hobby use purpose?

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Pito
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Re: 100MHz or 200MHz DSO

Post by Pito » Mon Nov 06, 2017 5:16 pm

Buying an oscope today is an extremely difficult task.
In hobby $$ region there is a lot of brands/types/configs. Except there are a lot of clones/copies/re-branded boxes, most of them are built around an overclocked ADC, an older generation FPGA (Altera, Xilinx), an MCU which is usually slow, mechanical parts which do not last long.. So a tear-down of an oscope on youtube or on the eevblog gives you some direction.
Best is to have a chance to play with several oscopes before the buy.
All cheaper scopes lack something different.
The well-known brand names are 5-20x more expensive with even much less features. There is an important point, however - the more features the manufacturers of "cheaper" oscopes pack into, the less functional/useful the features are..
For example - Oscope R is packed with features, but it divides sampling rate between the channels. Most of the features are so-so..
On the other hand Oscope T or K has got 1/x of the R features, but the sampling rate is constant when using more channels. Also these are with less features, those features are with more "professional touch"..
Etc., etc..
Frankly I doubt somebody is able to tell you which Oscope is "better" or "a good fit for the purpose", especially in the sub $1.5k region.
A good scope costs $450k.

PS: a good example you may see at eevblog (video) - Dave tested maybe 10 oscopes - specifically their "FFT feature". Guess the result..
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