Tektronix MSO 4 Series 500GS/s Equivalent Time Sampling?

[ftwang]

I just recently bought the MSO 4 series, and noticed that I can manually configure the sampling rate up to 500GS/s, even though the scope specification only lists it as 6.25GS/s.  For sampling rates above 6.25GS/s is the scope running in equivalent time sampling instead of real time sampling?  What is the benefit of such high sampling rate, when the bandwidth itself is limited to a maximum of 1.5GHz for this series?  Is it for the high-res mode...?

[Domitronic]

The datasheet says:

Sample rate range :
1.5625 S/s to 6.25 GS/s (real time)
12.5 GS/s to 500 GS/s (interpolated)

So i guess just some interpolation between the real time samples. Not sure what this would be used for. Maybe have a look at the user manual of the device.

[tv84]

I just recently bought the MSO 4 series, and noticed that I can manually configure the sampling rate up to 500GS/s, even though the scope specification only lists it as 6.25GS/s.  For sampling rates above 6.25GS/s is the scope running in equivalent time sampling instead of real time sampling?  What is the benefit of such high sampling rate, when the bandwidth itself is limited to a maximum of 1.5GHz for this series?  Is it for the high-res mode...?

(Attachment Link)

I also would like to know, from the gurus here, why a brand like Tek has the need to advertise such a gymnic. 

[ftwang]

Thanks! Unfortunately I couldn't find anything in the manual nor on Tek's website.

I think you are right though that the scope is just interpolating between the sampled points. I zoomed into the plot and changed the waveform display to "dots".  It shows that the scope is still sampling at 6.25GS/s, not sure why Tek advertise this "interpolated" sampling rate.

[Domitronic]

From the manual / printable help:

Interpolated Real-Time sampling
In interpolated real-time sampling, the instrument digitizes all of the points it acquires using one trigger event. If the instrument cannot
acquire enough samples for a complete waveform at the maximum real-time sample rate, it interpolates. Use interpolated real-time
sampling to capture single-shot or transient events.

[Sighound36]

Just like the time we had the Tek 6000 that clearly showed Zeptosec jitter 

[nctnico]

I just recently bought the MSO 4 series, and noticed that I can manually configure the sampling rate up to 500GS/s, even though the scope specification only lists it as 6.25GS/s.  For sampling rates above 6.25GS/s is the scope running in equivalent time sampling instead of real time sampling?  What is the benefit of such high sampling rate, when the bandwidth itself is limited to a maximum of 1.5GHz for this series?  Is it for the high-res mode...?

Back in the old days DSOs has equivalent time sampling but with 6.25Gs/s that isn't needed for acquire a 1.5GHz signal. I guess the 'virtual' samplerate shows the amount of extra points created by doing interpolation but to me it seems like a useless number.