Rigol 1102E and Dave's Honor.

[Dark Prognosis]

Then how could Dave have recommended this scope so highly for so many years now?
Something smells when Dave highly recommends a 100Mhz scope yet it supposedly only does about 30mhz.

It is a 100MHz (or more) bandwidth scope. Feed in a sine wave until it's 3dB down and measure the frequency yourself.

but that is only true if the front end amplifier doesn't have the uumph to feed the ADC, which is likely true, but somewhat unexpected.
if the processor has to do math on three samples to get a 7 bits out of 8 accurate that's a different issue.. which is what appears to be going on.

So, you are going to continually say that your Siglent is internally a Rigol?

[tom66]

but that is only true if the front end amplifier doesn't have the uumph to feed the ADC, which is likely true, but somewhat unexpected.
if the processor has to do math on three samples to get a 7 bits out of 8 accurate that's a different issue.. which is what appears to be going on.

Huh? A lot of the parts in the Rigol are actually 300~700MHz parts. Like the VGA and ADC drivers, from memory. It's just got a ~130MHz bandwidth filter so you don't get horrible aliasing at 1Gsps sampling rate. If you ripped out the filters it would probably do 200~300MHz. But it wouldn't be any good at that frequency due to the aliasing effects.

[johansen]

Then how could Dave have recommended this scope so highly for so many years now?
Something smells when Dave highly recommends a 100Mhz scope yet it supposedly only does about 30mhz.

It is a 100MHz (or more) bandwidth scope. Feed in a sine wave until it's 3dB down and measure the frequency yourself.

but that is only true if the front end amplifier doesn't have the uumph to feed the ADC, which is likely true, but somewhat unexpected.
if the processor has to do math on three samples to get a 7 bits out of 8 accurate that's a different issue.. which is what appears to be going on.

So, you are going to continually say that your Siglent is internally a Rigol?

i don't recall what the consensus is but afaik most siglents are identical to attens.. rigol is on their own but the history of these three corporations and others are so identical its difficult to tell if they all don't work out of the same office.

[johansen]

but that is only true if the front end amplifier doesn't have the uumph to feed the ADC, which is likely true, but somewhat unexpected.
if the processor has to do math on three samples to get a 7 bits out of 8 accurate that's a different issue.. which is what appears to be going on.

Huh? A lot of the parts in the Rigol are actually 300~700MHz parts. Like the VGA and ADC drivers, from memory. It's just got a ~130MHz bandwidth filter so you don't get horrible aliasing at 1Gsps sampling rate. If you ripped out the filters it would probably do 200~300MHz. But it wouldn't be any good at that frequency due to the aliasing effects.

see this thread. https://www.eevblog.com/forum/buysellwanted/which-oscilloscope-is-better/msg31932/#msg31932

if the adc is actually good to 200Mhz then why do we have information loss at only 50mhz.
anyhow, i suspect all of these scopes are the same way, but people aren't looking at the waveform with a real time critical eye.

[tom66]

They do not work out the same office, that's nonsense. For one you can see completely different software and hardware design  concepts in teardowns and demo videos/reviews. For example Atten use non-45deg traces on the ADCs. Rigol don't. And I believe Atten used 4 x dual 80Msps ADC OC @ 125MHz instead of 5 x dual 40Msps ADC OC @ 100MHz in their 50/100MHz product.

The reason you're seeing information loss is going to be down to probing and the characteristics of the circuit. I have used my 1102E up to 100MHz with no "information loss".

And, as stated, these models have a deliberate ~130MHz filter, so their input bandwidth is not 200MHz. But the design is (theoretically) capable of around that. It's just limited to avoid aliasing.

[echen1024]

but that is only true if the front end amplifier doesn't have the uumph to feed the ADC, which is likely true, but somewhat unexpected.
if the processor has to do math on three samples to get a 7 bits out of 8 accurate that's a different issue.. which is what appears to be going on.

Huh? A lot of the parts in the Rigol are actually 300~700MHz parts. Like the VGA and ADC drivers, from memory. It's just got a ~130MHz bandwidth filter so you don't get horrible aliasing at 1Gsps sampling rate. If you ripped out the filters it would probably do 200~300MHz. But it wouldn't be any good at that frequency due to the aliasing effects.

see this thread. https://www.eevblog.com/forum/buysellwanted/which-oscilloscope-is-better/msg31932/#msg31932

if the adc is actually good to 200Mhz then why do we have information loss at only 50mhz.
anyhow, i suspect all of these scopes are the same way, but people aren't looking at the waveform with a real time critical eye.

I own a Siglent SDS1102CNL, and can say that it is NOT the same as a Rigol. The Rigol is significantly more responsive, and updates faster.