Should I get a Keysight DSOX6004A ?

[2N3055]

Thought I'd give a follow up on my decision process...

I've decided not to take the offer on the Rigol 8000, I've searched a lot on this scope and cannot find any bad comments about it, everything about it looks great, price is unbeatable and at least on paper it ticks most of my requirements. However I just cannot see this as giving me the confidence that I need in a primary scope, I simply cannot get myself to accept a Rigol for this. If it were a secondary scope I'd definitely go for it though.

Meanwhile I came across the PicoScope 9400 series. I'm not a fan of PC based oscilloscopes for the general use case but this could make a lot of sense for my use case. The PicoScope 9400 can do eye diagram and jitter measurements at very high bandwidths using the SXRTO sampling technique (effectively this bandwidth would future-proof it for my requirements). I do realize that the SXRTO cannot be used for more general oscilloscope uses however I could then cover that requirement by getting a lower-end 1GHz normal sampling oscilloscope such as a WaveSurfer 4000HD, R&S, RTK4A, etc... Budget-wise this would be better since the overall cost would be lower and I can split the purchase of the two scopes over time. At the same time I'd have a 1GHz scope for general purpose use (which I require) and I'd also be able to do eye diagrams on high speed lines with the 9400 with a much higher bandwidth.

Do you think this makes sense?
Any opinions on the 9400?

My opinion:

12-bit 500 MS/s ADCs: how to go into fs??

±800 mV full-scale input range into 50 Ω: This means no 3.3V digital logic

10 mV/div to 0.25 V/div digital gain ranges: This means no 3.3V digital logic

while was looking at them to, as some figures missing 

or I am wrong

These are quite specialized instruments. Usually used with 10x or 20x probes.. Or with attenuators. They are not general purpose scopes.
Input connectors are SMA. It has 1 T(era)SMPS/sec equivalent sampling. 500 MSPS/sec is real time sampling rate of ADC.
They work only on repetitive signals, or signals where you want to accumulate samples on top of each other for eye diagrams...
Slower one has 0% to 90%: ≤ 70 ps and faster one has 10% to 90%: ≤ 21.9 ps..

[Sighound36]

Yes the Picoscope equipment is very good I have two of them, the staff are very helpful and always will try and find a solution if possible, I visited the factory last year and found ALL of the staff I met (Including the boss!) to be genuinelly enthusiatic and techincally excellent. The software is also very good.

If I didn't have the Lecroy's the Picoscope would be my next choice for accurate meas.

[grg183]

If you can afford that (and it seems that it might be even easier to purchase since you spread the cost over time)  a "sampling" scope and one general purpose scope is a best option. That way you can optimize each for the job.

Budget-wise this comes down to: $12k (assuming a WaveSurfer 4104HD) + $20k (assuming a Picoscope 9404-16), this gives me a capable 1GHz, 12bit, 4 channel general purpose scope and a dedicated 16GHz sampling scope for high speed signal analysis. Two instruments that I can use independently and together should cover all my requirements for general purpose capture as well as high speed analysis with a high enough bandwidth to cover all foreseeable future needs. I could also get the 5GHz model for $5k less and it would still be enough. On the other hand I could get a WaveProHD 2.5GHz which with the extra licenses is at least $50k and as far as high speed analysis goes I'd be "limited" to a 2.5GHz bandwidth. Don't get me wrong, I know that the WaveProHD has a ton of extra measurement tools in the app toolbox but I think with the WaveSurfer + Picoscope combo I'd be putting the money specifically where I need it while also spending less overall. I'm liking this idea a lot but still reviewing the pros and cons.

My opinion:

12-bit 500 MS/s ADCs: how to go into fs??

±800 mV full-scale input range into 50 Ω: This means no 3.3V digital logic

10 mV/div to 0.25 V/div digital gain ranges: This means no 3.3V digital logic

while was looking at them to, as some figures missing 

or I am wrong

As 2N3055 pointed out the 9400 is a highly specialized scope, the input range that it has is more than enough for it's intended use. You'd anyway need to use a x10 probe or attenuator. If you were to, for example, probe a DDR signal directly with the 50 ohm input it would anyway not be suitable as it loads the signal. The 9400 is not a scope you'd use for any "high voltage" applications really. It is also only suitable for repetitive signals.

Yes the Picoscope equipment is very good I have two of them, the staff are very helpful and always will try and find a solution if possible, I visited the factory last year and found ALL of the staff I met (Including the boss!) to be genuinelly enthusiatic and techincally excellent. The software is also very good.

If I didn't have the Lecroy's the Picoscope would be my next choice for accurate meas.

I don't have any Picoscopes (the only PicoTech device that I have is a TC-08 thermocouple data logger, which is great) but I have used a Picoscope 3000 (if I remember correctly) in the past and I remember it was really good. I'm not a fan of PC based oscilloscopes and definitely for a scope that would be used daily I want a box with screen and knobs, but the 9400 is something that has a very specific use so I don't mind that being PC based. The software also looks really refined.

[2N3055]

If you can afford that (and it seems that it might be even easier to purchase since you spread the cost over time)  a "sampling" scope and one general purpose scope is a best option. That way you can optimize each for the job.

Budget-wise this comes down to: $12k (assuming a WaveSurfer 4104HD) + $20k (assuming a Picoscope 9404-16), this gives me a capable 1GHz, 12bit, 4 channel general purpose scope and a dedicated 16GHz sampling scope for high speed signal analysis. Two instruments that I can use independently and together should cover all my requirements for general purpose capture as well as high speed analysis with a high enough bandwidth to cover all foreseeable future needs. I could also get the 5GHz model for $5k less and it would still be enough. On the other hand I could get a WaveProHD 2.5GHz which with the extra licenses is at least $50k and as far as high speed analysis goes I'd be "limited" to a 2.5GHz bandwidth. Don't get me wrong, I know that the WaveProHD has a ton of extra measurement tools in the app toolbox but I think with the WaveSurfer + Picoscope combo I'd be putting the money specifically where I need it while also spending less overall. I'm liking this idea a lot but still reviewing the pros and cons.

My opinion:

12-bit 500 MS/s ADCs: how to go into fs??

±800 mV full-scale input range into 50 Ω: This means no 3.3V digital logic

10 mV/div to 0.25 V/div digital gain ranges: This means no 3.3V digital logic

while was looking at them to, as some figures missing 

or I am wrong

As 2N3055 pointed out the 9400 is a highly specialized scope, the input range that it has is more than enough for it's intended use. You'd anyway need to use a x10 probe or attenuator. If you were to, for example, probe a DDR signal directly with the 50 ohm input it would anyway not be suitable as it loads the signal. The 9400 is not a scope you'd use for any "high voltage" applications really. It is also only suitable for repetitive signals.

Yes the Picoscope equipment is very good I have two of them, the staff are very helpful and always will try and find a solution if possible, I visited the factory last year and found ALL of the staff I met (Including the boss!) to be genuinelly enthusiatic and techincally excellent. The software is also very good.

If I didn't have the Lecroy's the Picoscope would be my next choice for accurate meas.

I don't have any Picoscopes (the only PicoTech device that I have is a TC-08 thermocouple data logger, which is great) but I have used a Picoscope 3000 (if I remember correctly) in the past and I remember it was really good. I'm not a fan of PC based oscilloscopes and definitely for a scope that would be used daily I want a box with screen and knobs, but the 9400 is something that has a very specific use so I don't mind that being PC based. The software also looks really refined.

I think that is good thinking.
I have Keysight MSOX3104T and 3 Picoscopes: MSO 3406D (500 MSPS), 4262 (16bit 5MHz low noise), and since few weeks 4824A (12bit, 20MHz 8ch beast).
All those functions in a single scope don't even exist. Maybe WaveRunner 8000HD would come close (not to 8uV of noise though), but I chose to buy new apartment instead...

As for being a fan (or not) of PC based instruments, it is a matter of habit and nothing more. I combined mine with a 23" touch screen monitor. If anything, it might be better than all in one scope for many things, depending on what you do.
Screen is bigger than whole 3000T, see below. As a side note, I'm monitoring 230V AC power in my lab. It's been up for a week, 24/7... Rock solid.
There is a new  version 7 software in making, but that will take some time. They are taking testing very seriously, and will release only when they think is rock solid. Talking about high professional standards. Many other manufacturers could make a note of that...

9400 software is actually different than standard Pico software, and it looks and feels even more refined. And as SI work is not button twiddling type of work, PC interface with everything nicely laid out on a large screen in a plain sight is an advantage in my view.

One more thing: ease of documentation. On a PC based scope it is simpler and faster. It is already on your PC...


 

[nctnico]

But still you have to keep in mind what kind of workflow you need. Some measurements require probing one point after the other and changing settings all the time while other measurements require taking one of two acquisitions and spend time to analyse/dissect the signal.

[Sighound36]

Just to keep things even more anal, with my Picoscope 4262 I built a isolated ultra quiet linear (round 4uA of ripple @ 5Vdc) supply for the scope via a usb break out box arrangement for those like me that loathe usb power especially on test instruments.

Yes I know 101 people will tell me I wasted my time, however it does seem to work 

[2N3055]

Just to keep things even more anal, with my Picoscope 4262 I built a isolated ultra quiet linear (round 4uA of ripple @ 5Vdc) supply for the scope via a usb break out box arrangement for those like me that loathe usb power especially on test instruments.

Yes I know 101 people will tell me I wasted my time, however it does seem to work 

 

[2N3055]

But still you have to keep in mind what kind of workflow you need. Some measurements require probing one point after the other and changing settings all the time while other measurements require taking one of two acquisitions and spend time to analyse/dissect the signal.

Signal integrity is a separate workflow..

[grg183]

As for being a fan (or not) of PC based instruments, it is a matter of habit and nothing more. I combined mine with a 23" touch screen monitor. If anything, it might be better than all in one scope for many things, depending on what you do. 

Well yes it is primarily a matter of personal preference I guess. Both have their advantages and disadvantages. Personally if it is something that I have to use very often I very much prefer it to be completely standalone, ideally with an alternative PC interface for when data needs to be transferred to the PC. If post-processing of data on the PC is essential then I'd agree a PC based device is generally better.

But still you have to keep in mind what kind of workflow you need. Some measurements require probing one point after the other and changing settings all the time while other measurements require taking one of two acquisitions and spend time to analyse/dissect the signal.

Signal integrity is a separate workflow..

I agree with 2N3055, signal integrity is very much an independent measurement and I see no limitation with this being done with a dedicated instrument.

[nctnico]

But still you have to keep in mind what kind of workflow you need. Some measurements require probing one point after the other and changing settings all the time while other measurements require taking one of two acquisitions and spend time to analyse/dissect the signal.

Signal integrity is a separate workflow..

I agree with 2N3055, signal integrity is very much an independent measurement and I see no limitation with this being done with a dedicated instrument.

That is good. I triggered on an earlier post of you where you are mentioning that you where also considering getting a scope for general purpose use. Unfortunately the perfect oscilloscope that fits all needs has not been created yet. Would save quite a bit of space if it existed

[egonotto]

Hello,

the WaveSurfer 4104HD is sure a great scope. But perhaps you should reflect, whether a R&S® RTA4K-COM4 give you more potential.

Drawback of the RTA4K it has the worser noise in lower sensitivities.
Example
31.4mV against 4.7mV in 1V/div range
4.6mV against 0.465mV in 100mV/div range
but:
0.11mV against 0.125mV in 1mV/div range.
But WaveSurfer 4104HD has 8 div and RTA4K has 10 div.

Best regards
egonotto

[Sighound36]

If you are looking for purely noise @ lower freqencices and you do not need to look above 200Mhz then the 4024 is the way to go, around 28uV of noise @ full bandwith open ports and no filters.

Much as I love R&S equipment and they do make some of the best RF gear on the planet without question, their scopes for me are as our lab miester from down under would say Meh! sorry its just way I feel about them for me no.

Then the Picoscope of your choice.

[grg183]

Interestingly some months ago (before I started researching for this purchase) I was almost about to grab the RTA4K-COM4 offer when I came across it...

The RTA4K is good scope, but compared to the 4104HD:
- higher noise
- 10 bit vs 12 bit
- 64k vs 175k waveforms/s
- 10 inch vs 12.1 inch screen

It wins on memory depth 100M/200M vs 12.5M/25M but it seems to me that with everything else the WaveSurfer is superior.
Currently I could get either one at the exact same price, so I think the WaveSurfer would be the obvious choice for me.

[bdunham7]

Any opinions on the 9400?

I don't have an opinion on the 9400 series, but Picoscopes in general are excellent if you don't need or want a 'conventional' setup, meaning form factor, PC-based vs one box and input characteristics. 

I would be very curious to know what the noise floor is on the various ranges and what sort of input probes/attenuators/etc work for you in various circumstances.  For example, is it possible to use the 10mV/div range and 100X passive attenuation so as to get the input impedance up.  I hope you can report back when you get it.

[Caliaxy]

Just to keep things even more anal, with my Picoscope 4262 I built a isolated ultra quiet linear (round 4uA of ripple @ 5Vdc) supply for the scope via a usb break out box arrangement for those like me that loathe usb power especially on test instruments.

Yes I know 101 people will tell me I wasted my time, however it does seem to work 

Have you noticed any improvement? It seems awkward that such a nice, low-noise piece of equipment is expected to rely on a computer USB port for power.

I'm not telling, I'm asking

[egonotto]

Hello,

If you are looking for purely noise @ lower freqencices and you do not need to look above 200Mhz then the 4024 is the way to go, around 28uV of noise @ full bandwith open ports and no filters.

This is far far .... far better than the 65 uV in the datasheet?

Best regards
egonotto

[Sighound36]

Hi Egonotto

I have found that every lecroy scope I own exceeds the quoted specs by a decent margin.

Though I have a confession the Wavesurfer is actually 48uv (42uv and BW to 20Mhz), my apologies I was confusing them with the 6054-MS that is 72uv ( so apologies for the mis information), my bad 

Scopes are in calibration, been on for hour, open ports 50Ohm no filters at all 1mv setting max sample rate

However it is still exceeds its quoted spec by a respectable margin.

[Sighound36]

Just to keep things even more anal, with my Picoscope 4262 I built a isolated ultra quiet linear (round 4uA of ripple @ 5Vdc) supply for the scope via a usb break out box arrangement for those like me that loathe usb power especially on test instruments.

Yes I know 101 people will tell me I wasted my time, however it does seem to work 

Have you noticed any improvement? It seems awkward that such a nice, low-noise piece of equipment is expected to rely on a computer USB port for power.

 

I'm not telling, I'm asking

I would suggest 100% yes the whole scope is just more stable, especially with FFT's and low noise meas  I feel it delivers a small but useful improvment  for the jobs I use it for, its plus from me.

[Sighound36]

I took some noise figures from the Lecroy last night (6054-MS) with an open port 50Ohm and fukk BW and one with a 20Mhz BW, the scope had only been running for a 15 minutes so not quite the usual readings, however you can see they are none to shabby!

[2N3055]

I took some noise figures from the Lecroy last night (6054-MS) with an open port 50Ohm and fukk BW and one with a 20Mhz BW, the scope had only been running for a 15 minutes so not quite the usual readings, however you can see they are none to shabby!

That is very short timebase. How would it look at 1mV/div, 10us/div?
Do you get around 25uV Stdev at 20MHz and 55 uV Stdev at 200MHz BW ?

[bdunham7]

I took some noise figures from the Lecroy last night (6054-MS) with an open port 50Ohm and fukk BW and one with a 20Mhz BW, the scope had only been running for a 15 minutes so not quite the usual readings, however you can see they are none to shabby!

Am I seeing two samples per screen??

[2N3055]

I took some noise figures from the Lecroy last night (6054-MS) with an open port 50Ohm and fukk BW and one with a 20Mhz BW, the scope had only been running for a 15 minutes so not quite the usual readings, however you can see they are none to shabby!

Am I seeing two samples per screen??

Are you saying you're seeing things ??
Just joking..

Yes you see right. What do you expect with 20ps/div. Yes, 20ps..

That is why I asked for a timebase that will take at least some 1E6 samples , but still staying fast enough not to pick up low frequency noise.
Also I have some notes written down from some previous testing, with those parameters, so I can directly compare..

[grg183]

You've probably all seen this already but just to add to the discussion here is a video comparing the noise figures for the WaveSurfer 4000HD with the RTA4K:
This video is made by Lecroy so it's not exactly what you'd call an unbiased review, but still...

[Sighound36]

Hi Sinisa

Some good calcultaions there first one is 1m/v @ 10us 20Mhz BW Std/d around 29uv

The BW on this cope is 500Mhz, no problem to produce one @ 200Mhz for you bang on 55uv

[2N3055]

Hi Sinisa

Some good calcultaions there first one is 1m/v @ 10us 20Mhz BW Std/d around 29uv

The BW on this cope is 500Mhz, no problem to produce one @ 200Mhz for you bang on 55uv

Thanks!!