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A new 5Mz scope using iPad, iPhone iPod Touch for UI.
I know little about scopes... comments?
dave
A new 5Mz scope using iPad, iPhone iPod Touch for UI.
I know little about scopes... comments?
dave
An interesting toy...
The analog BW of 5MHz is bumping right up against the Nyquist limit of the sampling rate of 12MS/s. The usable bandwidth at best 1/5 of the sample rate or 2.4Mhz.
The real bummer is the 240 point sample depth which makes it sort of a Fisher-Price "My First Oscilloscope".
At $298 it is grossly overpriced, you can buy a real single channel 20Mhz scope with 6k points capture depth for $30 more...
The analog BW of 5MHz is bumping right up against the Nyquist limit of the sampling rate of 12MS/s. The usable bandwidth at best 1/5 of the sample rate or 2.4Mhz.
The real bummer is the 240 point sample depth which makes it sort of a Fisher-Price "My First Oscilloscope".
At $298 it is grossly overpriced, you can buy a real single channel 20Mhz scope with 6k points capture depth for $30 more...
Or a dual 50mhz digital scope.
$339.99 - RIGOL DS1052E 5.6" TFT LCD 50MHz 2-Channel Digital Color Storage Oscilloscope - Professional Tools
$339.99 - RIGOL DS1052E 5.6" TFT LCD 50MHz 2-Channel Digital Color Storage Oscilloscope - Professional Tools
FWIW the Tek TDS-3054 stays FAR away from Nyquist. 500 MHz samples at 5 GHz. I've been using them for 13 years.
G²
I agree this is value for money. and fft feature which is good for checking
noise and frequency(speaker) spectrum plus other goodies.Very useful in deed.🙂
No, but very good used TEK scopes can be purchased on eBay for a few hundred dollars. I've bought several over the years with no problems - just need to make sure you are buying one from someone who can confidently state that it is in working order. (I.E. Avoid the "it lights up" and "I have no way to test it" sellers..)
A toy, admittedly a cool one, but performance on analog waveforms is probably not going to be that good..
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The price wasn't the point. The 10:1 bandwidth vs sample rate was. The 5MHz scope is more like 1-1.5 MHz with a 12 MHz sample rate.
G²
Thanx guys.
I do find the quoted statement interesting. 1/2 is to many "sufficient" for audio listening, what is it about sillyscopes that limits it to 1/5?
dave
Greatly oversimplified--the Nyquist frequency (1/2 the sample rate) is the upper limit for resolving sine waves. To accurately display faster rise time signals the sample rate needs to be a minimum of 3-4 times higher than the equivalent frequency of the rise time--5x faster is a rule of thumb, some engineers believe 10x to 20x is the proper ratio.
Take a look at the waveform coming out of most CD players with a test disk having a 10kHz or higher frequency sine wave recorded on it at various amplitudes and you will have your answer.
Good chance with a product such as this is that performance will be sub-par. Sample rate, A/D resolution, input attenuation, etc are all not going to be par with a good oscilloscope. A good reference is that PC based scopes are really not a factor in the test equipment market, and they have a lot more computing horsepower than an ipad.
If you think you need a scope, buy a scope. Anything else is just a toy.
paul
If you think you need a scope, buy a scope. Anything else is just a toy.
paul
Well, I have seen some VERY EXPENSIVE pc based scopes claiming to go out to 200megs... but at a cost where you'd be better off buying TEK.
It's all in the front-end, and PicoScope is probably the only manufacturer out there making decent analog front-ends.
Most USB "oscilloscopes" have lousy voltage dividers, horribly non-linear frequency response, and are single FPGA based meaning that they are incapable of reading both channels simultaneously--though many claim they do. I keep hoping for something decent and affordable, but mostly they are toys.
As a "Lecroy guy" I lean that direction, but the Tek scopes are also great instruments...
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