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Old Tektronix or new Hantek

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tggzzz:

--- Quote from: 2N3055 on December 05, 2024, 12:12:00 pm ---
--- Quote from: tggzzz on December 05, 2024, 12:02:47 pm ---
--- Quote from: ebourg on December 05, 2024, 08:48:10 am ---The Tektronix TDS3012B has 1.25 Gs/s per channel vs 1 Gs/s shared on the Hantek DSO2D10, but the Hantek has more memory depth. Don't buy the Hantek new, there are better alternatives at this price range (see the Siglent/Rigol threads).

--- End quote ---

Samples/second is an irrelevant metric: the only metric that matters is bandwidth.

Examples:

* 35 years ago I was using HP scopes to examine 800ps risetimes. It was 25MS/s
* I have a 200ps/1.7GHz 1970 scope that uses BC107 (fT=350GHz) transistors in the signal path
* I have a scope with <100ps risetimes and a 37kS/s sampling rate
--- End quote ---

Would you, please, stop confusing people with useless comments of how sampling scopes sample at slow sample speeds..
They do not. They have equivalent sampling rate defined by sample aperture of individual sample in reconstruction  process. They do not violate Nyquist, but cleverly reconstruct signal shape from thousands of separate trigger events.

And people are talking about Real Time sampling scope for which realtime sampling rate IS important.
You know, like ANY average scope made in the last 20 years...

And in the last more than 10 years, scopes mostly don't even provide ETS function anymore..

--- End quote ---

Please read and understand what I wrote in context, before having a knee-jerk response.

I used those examples to illustrate why a scope's sample/second metric is meaningless. In particular comparing 1.25GS/s with 1.0GS/s is not useful: they are both 100MHz scopes!

The only metric that matters is the bandwidth.

2N3055:

--- Quote from: tggzzz on December 05, 2024, 02:09:20 pm ---
--- Quote from: 2N3055 on December 05, 2024, 12:12:00 pm ---
--- Quote from: tggzzz on December 05, 2024, 12:02:47 pm ---
--- Quote from: ebourg on December 05, 2024, 08:48:10 am ---The Tektronix TDS3012B has 1.25 Gs/s per channel vs 1 Gs/s shared on the Hantek DSO2D10, but the Hantek has more memory depth. Don't buy the Hantek new, there are better alternatives at this price range (see the Siglent/Rigol threads).

--- End quote ---

Samples/second is an irrelevant metric: the only metric that matters is bandwidth.

Examples:

* 35 years ago I was using HP scopes to examine 800ps risetimes. It was 25MS/s
* I have a 200ps/1.7GHz 1970 scope that uses BC107 (fT=350GHz) transistors in the signal path
* I have a scope with <100ps risetimes and a 37kS/s sampling rate
--- End quote ---

Would you, please, stop confusing people with useless comments of how sampling scopes sample at slow sample speeds..
They do not. They have equivalent sampling rate defined by sample aperture of individual sample in reconstruction  process. They do not violate Nyquist, but cleverly reconstruct signal shape from thousands of separate trigger events.

And people are talking about Real Time sampling scope for which realtime sampling rate IS important.
You know, like ANY average scope made in the last 20 years...

And in the last more than 10 years, scopes mostly don't even provide ETS function anymore..

--- End quote ---

Please read and understand what I wrote in context, before having a knee-jerk response.

I used those examples to illustrate why a scope's sample/second metric is meaningless. In particular comparing 1.25GS/s with 1.0GS/s is not useful: they are both 100MHz scopes!

The only metric that matters is the bandwidth.

--- End quote ---

But you are wrong.
You cannot have a scope with a 100MHz BW with realtime sampling of 120MS/s.
It violates Nyquist and won't show you actual signal, but a downconverted version.

tggzzz:

--- Quote from: 2N3055 on December 05, 2024, 02:25:44 pm ---
--- Quote from: tggzzz on December 05, 2024, 02:09:20 pm ---
--- Quote from: 2N3055 on December 05, 2024, 12:12:00 pm ---
--- Quote from: tggzzz on December 05, 2024, 12:02:47 pm ---
--- Quote from: ebourg on December 05, 2024, 08:48:10 am ---The Tektronix TDS3012B has 1.25 Gs/s per channel vs 1 Gs/s shared on the Hantek DSO2D10, but the Hantek has more memory depth. Don't buy the Hantek new, there are better alternatives at this price range (see the Siglent/Rigol threads).

--- End quote ---

Samples/second is an irrelevant metric: the only metric that matters is bandwidth.

Examples:

* 35 years ago I was using HP scopes to examine 800ps risetimes. It was 25MS/s
* I have a 200ps/1.7GHz 1970 scope that uses BC107 (fT=350GHz) transistors in the signal path
* I have a scope with <100ps risetimes and a 37kS/s sampling rate
--- End quote ---

Would you, please, stop confusing people with useless comments of how sampling scopes sample at slow sample speeds..
They do not. They have equivalent sampling rate defined by sample aperture of individual sample in reconstruction  process. They do not violate Nyquist, but cleverly reconstruct signal shape from thousands of separate trigger events.

And people are talking about Real Time sampling scope for which realtime sampling rate IS important.
You know, like ANY average scope made in the last 20 years...

And in the last more than 10 years, scopes mostly don't even provide ETS function anymore..

--- End quote ---

Please read and understand what I wrote in context, before having a knee-jerk response.

I used those examples to illustrate why a scope's sample/second metric is meaningless. In particular comparing 1.25GS/s with 1.0GS/s is not useful: they are both 100MHz scopes!

The only metric that matters is the bandwidth.

--- End quote ---

But you are wrong.
You cannot have a scope with a 100MHz BW with realtime sampling of 120MS/s.
It violates Nyquist and won't show you actual signal, but a downconverted version.

--- End quote ---

Has that been suggested anywhere in this thread?

If not, why are you raising a strawman argument?

2N3055:

--- Quote from: tggzzz on December 05, 2024, 02:28:33 pm ---
--- Quote from: 2N3055 on December 05, 2024, 02:25:44 pm ---
--- Quote from: tggzzz on December 05, 2024, 02:09:20 pm ---
--- Quote from: 2N3055 on December 05, 2024, 12:12:00 pm ---
--- Quote from: tggzzz on December 05, 2024, 12:02:47 pm ---
--- Quote from: ebourg on December 05, 2024, 08:48:10 am ---The Tektronix TDS3012B has 1.25 Gs/s per channel vs 1 Gs/s shared on the Hantek DSO2D10, but the Hantek has more memory depth. Don't buy the Hantek new, there are better alternatives at this price range (see the Siglent/Rigol threads).

--- End quote ---

Samples/second is an irrelevant metric: the only metric that matters is bandwidth.

Examples:

* 35 years ago I was using HP scopes to examine 800ps risetimes. It was 25MS/s
* I have a 200ps/1.7GHz 1970 scope that uses BC107 (fT=350GHz) transistors in the signal path
* I have a scope with <100ps risetimes and a 37kS/s sampling rate
--- End quote ---

Would you, please, stop confusing people with useless comments of how sampling scopes sample at slow sample speeds..
They do not. They have equivalent sampling rate defined by sample aperture of individual sample in reconstruction  process. They do not violate Nyquist, but cleverly reconstruct signal shape from thousands of separate trigger events.

And people are talking about Real Time sampling scope for which realtime sampling rate IS important.
You know, like ANY average scope made in the last 20 years...

And in the last more than 10 years, scopes mostly don't even provide ETS function anymore..

--- End quote ---

Please read and understand what I wrote in context, before having a knee-jerk response.

I used those examples to illustrate why a scope's sample/second metric is meaningless. In particular comparing 1.25GS/s with 1.0GS/s is not useful: they are both 100MHz scopes!

The only metric that matters is the bandwidth.

--- End quote ---

But you are wrong.
You cannot have a scope with a 100MHz BW with realtime sampling of 120MS/s.
It violates Nyquist and won't show you actual signal, but a downconverted version.

--- End quote ---

Has that been suggested anywhere in this thread?

If not, why are you raising a strawman argument?

--- End quote ---

Problem is that it is you that have a knee jerk response without knowing whole discussion.
Yes, exactly THAT was discussed.

A scope with claimed 250 MHz BW and sampling of 312.5 MS/sec.
Do you understand now?

Of course that if you sample 100MHz BW with 500MS/s, 1GS/sec or 1.25GS/sec, that in that case it does not matter.
It is a 100MHz BW scope. And your statement means that. I agree.

But that was not discussed, but mathematically insufficient sampling...
And than you jump in with "sampling rate does not matter..." argument.  :-//

Of course I reacted.

Conrad Hoffman:
It took 12-bit to get me away from analog scopes. I've used 8/9 bit scopes at work for years and they didn't move me enough to get one, no matter how fast or expensive. The memory depth on the older scopes is too small. Plus, the FFT on 8/9 bit scopes seems near to worthless for any real world problem. Depending on what you're doing, # of channels and bandwidth, even the lower end Siglent SDS800 series could make you quite happy for not much $$.

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