Rigol's New DHO800 Oscilloscope unbox & teardown

[dreamcat4]

I assume they're encrypted or something because they're completely different inside.

here is answer from the thread on hacking the 1000 / 4000 series:

A tool to decrypt the vendor.bin and generate a license key can be found here: https://gitlab.com/riglol/rigolee/hdo-tools. To use the license generator, one must have ssh access to the scope, to extract the key file from it (or use usb-uart and extract it like that somehow). Best extract the key at least once, and back it up, before updating any firmware, who knows what gets locked down later

[iMo]

Theoretically yes. When people here indicate the modern scopes use lower sample rate vs. BW (like 2.5xBW) because the newer design includes better/sharper filters (ie. the existing LC higher order low-pass filter at each of the ADC's inputs) - and the 800/900 models indeed are designed that way, it seems - there is always a probability they designed the low-pass filters such the filter's BW fits the particular model - it means the 70MHz model would require a differently designed filter as the 100MHz model or the 250MHz model, etc. How the real situation is - I do not know..

PS: the LC filters at the ADC input are hardwired, you cannot change them in software, you have replace them on the pcb.

There is an higher order LC low pass in the front of the ADC in all channels (in 800/900/1000 series I saw videos of). It could easily be the low-pass has been tuned for each type (based on the BW) a little bit differently. It is not about what Rigol says or usually does, but what you will be measuring in reality. Also the various revisions of hw and fw might come with changes. Thus either people want "to know", or "it does not matter" for them how their stuff works in this price range..

Are you suggesting that possibly even if the FW could be hacked, there may be model specific hardware differences that might prevent a lower spec model from running at the full bandwidth of a higher spec model, even if the software was not aware of the difference and identified itself properly as a higher spec model?

[Martin72]

it means the 70MHz model would require a differently designed filter as the 100MHz model or the 250MHz model, etc. How the real situation is - I do not know..

Unlike the 1000/4000 models, you can't buy a single upgrade(bandwith, memory, decoding, etc.), as of now.
Neither for the 800 nor for the 900.

[iMo]

When you look at the pcb close to the ADC you may see there the 4 filters - each of them consists of 4 inductors and 2 capacitors (see my simulation example above) in all 800/900/1000/4000 models. What could be different in each model are the values of the L and C components which determine the BW and roll-off of the filter.
That filter in each channel is the CSF for your hacking effort 

[Fungus]

How the real situation is - I do not know..

Unlike the 1000/4000 models, you can't buy a single upgrade(bandwith, memory, decoding, etc.), as of now.
Neither for the 800 nor for the 900.

Yes, but logistically it makes far more sense to only manufacture one variant of PCB then soft-select the bandwidth based on incoming orders.

[Martin72]

What could be different in each model are the values of the L and C components which determine the BW and roll-off of the filter.

I'm more with Fungus, I can't imagine that rigol makes the effort and equips different values.
We will find out soon, or I would measure my 804 first so, then after the hack on 100Mhz or higher.

[Fungus]

What could be different in each model are the values of the L and C components which determine the BW and roll-off of the filter.

I'm more with Fungus, I can't imagine that rigol makes the effort and equips different values.

We also know they didn't make the effort to remove all the LA components from the 800's PCB.  It has a lot of unnecessary components.

The only conclusion is that running two separate production lines would be more expensive than leaving them on.

[nctnico]

Theoretically yes. When people here indicate the modern scopes use lower sample rate vs. BW (like 2.5xBW) because the newer design includes better/sharper filters (ie. the existing LC higher order low-pass filter at each of the ADC's inputs) - and the 800/900 models indeed are designed that way, it seems - there is always a probability they designed the low-pass filters such the filter's BW fits the particular model - it means the 70MHz model would require a differently designed filter as the 100MHz model or the 250MHz model, etc. How the real situation is - I do not know..

No. The filter is the same for all models; it is the anti-aliasing filter for the ADC. The bandwidth limit is set in the analog front-end as a first order roll-off. You can buy analog front-end amplifier chips that have this feature. It also allows for user selectable bandwidth limits. It is all software.

[tautech]

Theoretically yes. When people here indicate the modern scopes use lower sample rate vs. BW (like 2.5xBW) because the newer design includes better/sharper filters (ie. the existing LC higher order low-pass filter at each of the ADC's inputs) - and the 800/900 models indeed are designed that way, it seems - there is always a probability they designed the low-pass filters such the filter's BW fits the particular model - it means the 70MHz model would require a differently designed filter as the 100MHz model or the 250MHz model, etc. How the real situation is - I do not know..

No. The filter is the same for all models; it is the anti-aliasing filter for the ADC. The bandwidth limit is set in the analog front-end as a first order roll-off. You can buy analog front-end amplifier chips that have this feature. It also allows for user selectable bandwidth limits. It is all software.

Yep, to as you say the limit of the analog input design.
Then the VGA determines the model by limiting BW.

[nidlaX]

Has anyone investigated adding back the logic analyzer functionality yet? From what I've read so far, it sounds like you'll need to solder in the two missing DRAM chips, is that right?

[hbozyq]

Apparently there's an extended calibration menu that can be enabled. Would that fix it?

Sadly, offset is still there.

[hubertyoung]

hmmm, amazing

[Luc7777]

hmmm, amazing

Can you share your findings?

[hubertyoung]

hmmm, amazing

Can you share your findings?

Through this link https://gitlab.com/riglol/rigolee/hdo-tools I have obtained a method for generating licenses. Then, with the help of DHO900's programming manual, modify the code in rgtool.go.
1. Flag. StringVar (&deviceId, "id", "HDO4XXXXXX", "device Id") at line 29 changes HDO4XXXXXX to DHO9XXXXXX,
2. The return value of the MakeLicense method is fmt. Printf ("HDO4000-% s @% s", feature, res) at line 164, where HDO4000 is modified to DHO900.
3. At line 224, modify the ': SYSTEM: OPT: INST% v' of fmt. Printf (': SYSTEM: OPT: INST% v', lic) to ': SYSTem: OPTion: INSTall'
4. The array of options at line 212 has been modified to BODE. Currently, I have read the manual that only supports this type of authorization.
After completing the above modifications, rerun the rgtool.go and the output will be printed in the terminal. For example.
: SYSTem: OPTion: INSTall DHO900-BODE@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxf080b6c8
Then connect the oscilloscope to the network cable and use the menu on the web to enter the above content. You can install authorization.

[Nikki Smith]

Has anyone investigated adding back the logic analyzer functionality yet? From what I've read so far, it sounds like you'll need to solder in the two missing DRAM chips, is that right?

I'm going to try. I've got a DHO804 and I've designed a clone logic analyser board, but I haven't built + tested it yet (just waiting for the components to arrive):
https://climbers.net/sbc/clone-pla2216-logic-probe-analyzer/

I'm not brave enough to solder those DRAM chips myself, so I need to find a local expert for that.

[Bicurico]

Sorry for the lazy question (I could have searched it):

What is the price difference between both models? Does it economically make sense to solder DRAM's and a custom made PCB?

[Nikki Smith]

Sorry for the lazy question (I could have searched it):

What is the price difference between both models? Does it economically make sense to solder DRAM's and a custom made PCB?

The cost between the cheapest DHO804 and the cheapest DHO914 is 240€ or £205 (Rigol EU, inc 20% VAT). The DHO900 series would still require a separate logic analyser, it just has the 50-way connector on the front of the scope: the Rigol PLA2216 is another £304 / 356€. Hence the attractiveness of a cheap clone logic analyser board that works with the 900 (and maybe a hacked 800)!

The DHO914S model with the AFG is another 120€ or £105 on top of those prices.

[Fungus]

The cost between the cheapest DHO804 and the cheapest DHO914S is 360€ or £310 (Rigol EU, inc 20% VAT).

You don't have to buy the 'S' model though. The ordinary DHO914 costs less.

[dreamcat4]

The whole thing can be summarize as such:

For the money AFG / AWG just doesn't seem worth it, given the price differences. Which is (other than better probes, or to test the product's performance) the only clear reason for not getting the 804.

But even for the difference beterr 914 and 914S it's just such a meh AWG (single channel, 25mhz)... makes getting a dedicated function generator then such a much more attractive prospect. For example the UNI-T UTG962E (which is 2ch, 60mhz).

Especially if you got the 804. Then your remaining budgetary coins might have left over even yet for something like nanoVNA also (to do the bode plots with).

[souldevelop]

Guys , if you have a DHO914 or DHO924 note without (S)AFG please send a snapshot image of the system about here, I would like to see how the hardware version number is different. Thank!

[hubertyoung]

Has anyone investigated adding back the logic analyzer functionality yet? From what I've read so far, it sounds like you'll need to solder in the two missing DRAM chips, is that right?

I'm going to try. I've got a DHO804 and I've designed a clone logic analyser board, but I haven't built + tested it yet (just waiting for the components to arrive):
https://climbers.net/sbc/clone-pla2216-logic-probe-analyzer/

I'm not brave enough to solder those DRAM chips myself, so I need to find a local expert for that.

Have you done equal length differential signal processing? The signals I understand may have frequencies of tens of megabytes

[Luc7777]

Has anyone investigated adding back the logic analyzer functionality yet? From what I've read so far, it sounds like you'll need to solder in the two missing DRAM chips, is that right?

I'm going to try. I've got a DHO804 and I've designed a clone logic analyser board, but I haven't built + tested it yet (just waiting for the components to arrive):
https://climbers.net/sbc/clone-pla2216-logic-probe-analyzer/

I'm not brave enough to solder those DRAM chips myself, so I need to find a local expert for that.

Hi,
I have managed to install the key, got the 4th option in the menu (BODE PLOT) but I can't find the BODE option in the menu.

[dreamcat4]

have managed to install the key, got the 4th option in the menu (BODE PLOT) but I can't find the BODE option in the menu.

yes but does it need the 's' hardware (built in awg module) to drive the signal for doing a bode plot? or is there some chances of a capability to drive with external signal instead? (for example like siglent eh)

[Mortymore]

...Then your remaining budgetary coins might have left over even yet for something like nanoVNA also (to do the bode plots with).

I don't think it's possible to do a Bode Plot with it in the audio frequency region though.
As far I could tell, the lowest frequency on the nanoVNA variants start at 10KHz ... 50KHz.

If I'm wrong, please let me know because I'm interested.

[dreamcat4]

not so straightforward / not so easy. but there are methods in hardware to mix down frequency into lower domains. and so there are ways but...

for audio range you might be better off just using a more appropriate equipment then. so the example given was standalone regular awg for that task. but if i understand your query it's more about integrations to automatically run the sweep to generate the graphs.

nano vna is more about testing antennas and higher freq work.