Oscilloscope for hobbyist

[renzen]

Can anyone give me suggestion what oscilloscope I should buy? Can measure max frequency around 1-2 MHz and able to see rise/fall time 10-50ns.
Prefer USB oscilloscope, so I can save the measurement for later. Of course, the most important, cheap
Many hobbyist buy Hantek6000BE. Does it suit for me? If not, what specification should I look? What is the minimum sample rate so I can measure max frequency around 1-2 MHz and able to see rise/fall time 10-50ns?
Thanks in advance and sorry for my poor English

 

[cowboybob]

With the rise/fall time specification you list, here's a group of PC scopes to consider: **broken link removed**

Note that I have the 2206A selected. Bandwidth is higher than you specify, but that's how it goes with the rise/fall spec you list:

You also didn't set a desired price range, so something other than the 2206A might better suit your needs.

Note that these units are also signal generators.

I should note that I have no personal experience with these devices.

 

[Flyback]

to measure 2 MHz you need a sample rate of 4Mhz or better. Also, your bandwidth should be higherthan 2mhz as 2Mhz is the 3db frequency, where it is somewhat attenuated. You need a bandwidth of some 20MHz +

 

[Flyback]

To think about rise time, you need to think of a sine wave, and then think of the bit as it crosses zero, and for how long is that straight....if 10ns is your rise time requirement then that means that the sine wave that you must depict has a wavelength of around 20ns so that's 50mhz bandwidth needed. (possibly a bit less)...you have to think of the gradient of the bit of the sine wave that is the steepest bit.

typically though , people use the constant "0.35", so for 10ns rise time, you need a bandwidth of 0.35/10ns = 35Mhz

 

[Flyback]

Remember though, as the following page 2 says, its the "MEMORY LENGTH" that ultimately determines the sampling rate and bandwidth of your oscilloscope......if you haven't got enough memory length, then all the bandwidth and all the sampling rate in the world will do you no good
**broken link removed**

"Memory length is the sole , single MOST important parameter in sourcing an oscilloscope.

Look on your scope, if you have it on 100us/div, then you have 1ms worth of waveform on the scope screen...if you memory length is 1000 words, then that means it will capture 1000 equally spaced pieces of that 1ms scope trace.....so that means it captures every 1us....which means you have a sample rate of 1Ms/sec...which is pretty lousy as it means your bandwidth is only around 400khz...(assuming you have enough analog bandwidth and sampling rate in the first place to cover this).

Memory length....that is the crux of the matter

 

[fezder]

personally i have rigol ds1054, good value for money....and i still have analog scope too, so i highly recommend getting yourself analog scope too, and even cheap signal analyzer
Analog scope is good when you don't care for small details and other good points too over digital
Digital is good due memory, you can measure small bursts like IRC (in rush current/spikes) and low freguency signals, like around 5hz or even lower, you get my point
Analyzer is good for, well analyzing....
sorry if this message was total carbage, it's late in here (lousy excuse, eh?)

 

[Tony Stewart]

There's a huge performance and feature difference between a $100 and $400 scope.
Consider used until you can get the best scope you can afford.

e.g. Analog or digital, depends on needs
Analog https://www.ebay.com/itm/Tektronix-2230-100-MHz-Digital-Storage-Oscilloscope-/131588560869 $1/MHz

Digital **broken link removed** $3/MHz

The ARM based NANO may be ok for some things but easily get false triggers in a strong EMI environment, wont catch glitches nor evaluate rise time very well on fast MOSFET switches.