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Pico-scope 2205...

Which product is right for your exact requirements

Pico-scope 2205...

Postby Guest » Tue Nov 04, 2008 5:19 pm

Hello!

I'm having a real "blond moment" this afternoon and need your help to confirm a fact about the 2205.

What is the effective frequency of the 2205? Although it's stated that it can handle 400GS/s, does this translate to a 400Ghz scope?!? The bit that has got me worried is that for a continuous streaming signal, the datasheet states that it will process 1MS/s, which I'm reading as it's a 1MHz scope! I'm also reading the 50ns time base as 20MHz.

I'm so confused, please put my stupid brain at ease!

Regards,

Pete.
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Postby Robin » Wed Nov 05, 2008 10:34 am

Hello

The bandwidth of the 2205 is 25 MHz and it has a maximum sampling rate of 200 MS/s.

The 4 GS/s refers to when you are measuring repetative signals. In this case, the scope operates in equivalent time sampling mode. However, you are still limited by the 25 MHz bandwidth. The higher sampling rate just gives you a more accurate picture of the waveform.

Scope can operate in streaming mode or block mode. In streaming mode, data is sent continouusly to the PC via USB, which limits the sampling rate to 1MS/s. This is not the case in block mode as a block of data is captured in the scope's memory and then transferred to the PC.

I hope this helps

Robin
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Just a thought...

Postby Guest » Mon Nov 10, 2008 11:59 am

Robin,

Thank you for your reply. I've just had a thought, that 50ns on the time base which will be 50ns per division, isn't it? That means your scope will be a lot faster than I originally calculated.

Also, if I try to input a signla that is too fast for it, will it take as many samples as it can and then try to "smooth out" the response...?

I'm damn sure I'm going to buy one now, I just need to verify the last few details.

Cheers!

Pete.
Guest
 

Postby Robin » Mon Nov 10, 2008 2:09 pm

Hi Pete

Yes, the shortest timebase is 50 ns per division, which is 500 ns per screen. However, when thinking about speed, it is the sampling rate that is important. Using short timebases may just mean that you display fewer samples.

Also, the bandwidth is important. The 2205 has a bandwidth of 25 MHz.

If you have a signal that is not sampled at least twice per wavelength, then you will get aliasing and the signal will appear to have a lower frequency. However, if you stay within the 2205's bandwidth, this shouldn't be a problem.

Regards

Robin
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