EEVblog #892 - Siglent SSA3021X Spectrum Analyser Teardown

[coppice]

PS: considering the comments on the last video comparing the two SP and the fact you did not have it for long I wonder what are the reactions from Siglent on the level of design detail given as well as just opening it?

I just got an email from Siglent, they loved the teardown.

They might have liked it less if you'd done a parallel teardown of the 3.2GHz model, and found the hardware was identical.

We already know it is.

Where is the information which confirms this? All I have seen it that the feature packs are enabled by a key.

[Smokey]

Paging Shahriar... Shahriar... Please report to the EEVBlog for comments on RF gear....
https://www.eevblog.com/forum/profile/?u=8240


I wonder if Dave violated their video blogger to video blogger agreement where Dave won't do RF gear and Shahriar won't take apart stuff people send him in the mail.

[tautech]

PS: considering the comments on the last video comparing the two SP and the fact you did not have it for long I wonder what are the reactions from Siglent on the level of design detail given as well as just opening it?

I just got an email from Siglent, they loved the teardown.

They might have liked it less if you'd done a parallel teardown of the 3.2GHz model, and found the hardware was identical.

We already know it is.

Where is the information which confirms this? All I have seen it that the feature packs are enabled by a key.

Not officially, but read this thread and make up your own mind:
https://www.eevblog.com/forum/testgear/hack-of-sigllent-spectrum-analyzer-ssa3021x/


BTW already linked in reply #7

[EEVblog]

I wonder if Dave violated their video blogger to video blogger agreement where Dave won't do RF gear

This is only my 3rd spectrum analyser teardown 

[rf-loop]

PS: considering the comments on the last video comparing the two SP and the fact you did not have it for long I wonder what are the reactions from Siglent on the level of design detail given as well as just opening it?

I just got an email from Siglent, they loved the teardown.

They might have liked it less if you'd done a parallel teardown of the 3.2GHz model, and found the hardware was identical.

We already know it is.

Where is the information which confirms this? All I have seen it that the feature packs are enabled by a key.

Is it better to read this EEVblog forum bit more deeply.

Independent of this and without deep knowledge how different manufacturers optimise they production and models.
If look Dave's photographs from boards it do not need very deep knowledge to know that if make these, example qty 100 and run statistics with several test parameters you find that every single unit is different, more or less. Analg RF world is - fun. (Btw, in images I can not fid signs about laser or other method individually trimmed filters or other things etc...)
In finally you may find (I do not say Siglent find) that some units are wise to sell as 1.5G models, some may be ok for 2G and some may be ok for 3G. It depends how we set our parameters limit values. Then configure (digitally) these units to different models. If I'm manufacturer I do this.  Also Analog Devices do even with simple chips labelling them to 40MHz or 100MHz.... and so on..

[nowlan]

Re: RF sections;
All those hititte chips made me wonder if it was a reference design, or outsourced.

[rf-loop]

Re: RF sections;
All those hititte chips made me wonder if it was a reference design, or outsourced.

Really? Do you really believe that company like Siglent do not have enough well educated and experienced RF engineers for design this kind of simply front end where is nothing special. Siglent is also ODM so if you want something like this you can buy this design from Siglent.
Just simple cheap front end without any kind of special "High-End" or "State of art" level things. Why it need outsource design with high risk. All these kind of things need tightly keep inside house. Also they have experince with they older SA models 1010 and 3030. If development team do  years work and this is result I do not wonder at all this result, perhaps I hope result is better... but, this is much more than crap, so public "raise the cup and give a round of applause"  to Siglent SSA product department development team. In this price result is not bad.

[classical]

Thank you for this great teardown! The Image with block diagram overlay was really well done and extremely helpful. Threre is a lot of work in it. I do appreciate it.

[coppice]

Where is the information which confirms this? All I have seen it that the feature packs are enabled by a key.

Is it better to read this EEVblog forum bit more deeply.

Independent of this and without deep knowledge how different manufacturers optimise they production and models.
If look Dave's photographs from boards it do not need very deep knowledge to know that if make these, example qty 100 and run statistics with several test parameters you find that every single unit is different, more or less. Analg RF world is - fun. (Btw, in images I can not fid signs about laser or other method individually trimmed filters or other things etc...)
In finally you may find (I do not say Siglent find) that some units are wise to sell as 1.5G models, some may be ok for 2G and some may be ok for 3G. It depends how we set our parameters limit values. Then configure (digitally) these units to different models. If I'm manufacturer I do this.  Also Analog Devices do even with simple chips labelling them to 40MHz or 100MHz.... and so on..

So, what you are trying to say is you have no idea, right? It might be the same hardware. It might not. It almost certainly fairly similar, but maybe they use a higher spec version of some key parts.

[xrunner]

I'd probably consider it if I hadn't already bought a DSA815-TG last year. Something new and better always comes out, that's the way it goes. But for my hobby uses the DSA-815 is perfectly fine.

[bitwelder]

This teardown was really good, thesignalpath-good
My vote:  O0 O0 O0 O0 (4 Shariars)

[nctnico]

So, what you are trying to say is you have no idea, right? It might be the same hardware. It might not. It almost certainly fairly similar, but maybe they use a higher spec version of some key parts.

I don't believe they leave producing the 2 or 3GHz model to chance. With modern production processes you can build every unit to precise specifications. If you have different versions you'll also need different microstrip filters so you'll also need two different board designs. Taking the chance with lower spec components isn't going to cut it either. For example: there are many RF switches on the board. If some of them operate to >3GHz and some not the chance of creating a 3GHz capable SA is nearly 0. Also if demand is greater for the 3GHz model you will be left with a whole bunch of boards which you can't sell. So either all units are the same and work up to 3.x GHz or they have specific designs for the 2.xGHz and 3.xGHz models.

[albert22]

 
VERY good video.
Thanks

[TurboTom]

There are quite a few amazing details about the Siglent SSA3021X and the Rigol DSA815 that they have in common. The design of the RF path right to the first mixer is almost identical (a few components are different but function-wise it's exactly the same). Quite funny is the use of the first mixer "in reverse", i.e. RF is applied at the "IF" output of the mixers (HMC488 in case of the Siglent, probably HMC213 in the Rigol -- the surface is lasered blank here) while the mixing product is taken from the RF input. Since the mixers are passive devices (double-balanced diode bridges), this is possible and permits input frequencies (thoretically) down to DC. Both LO and RF "inputs" of the mixers are transformer-coupled and hence have a lower frequency limit. What makes me wonder though if the existing hardware of the 2.1G siglent spectrum analyzer is really capable of 3.2G is the fact that the mixer's IF range is actually specified to 2.5G only. This may be just a limit imposed by the way Hittite has tested this device but it gives some reason for doubts. The HMC213 that I assume to be used in the DSA815 is specified to 1.5G IF so this matches the operational range of this analyzer.

Well, that's just food for thought.

Another interesting detail is that Siglent used a one-wire unique ID ROM chip (U48, DS2401) on their application processor. Could it be possible that Siglent got batches of ID ranges that refer to a certain frequency version of the analyzer? Or maybe have odd IDs on 2.1G machines and even on 3.2G or vice versa? Or is it just there to be able to identify every single analyzer in the field and prevent it from being tampered with? I would really like to know if the machine still runs without that chip...

I guess the Siglent SA will become a new "hacker's paradise"... 

Oh - just noticed: In the lower right corner of the control board, next to the buzzer, there's an unpopulated footprint of a four-pin header labled "uart". I guess that's the place too look first... Maybe it's easier to get into that thing than expected!

Cheers,
Thomas

[nctnico]

Still what makes me wonder is that many Hittite chips used in this SA are declared obsolete.

[tautech]

Still what makes me wonder is that many Hittite chips used in this SA are declared obsolete.

Really? How?

As rf-loop has alluded to, development will have taken some years and in that time ANY IC's production status can change for whatever reason. Part obsolescence can even result from a change to ROHS compliance or better spec'ed chip in the same package but who knows.
Have you never encountered this (of course you f***ing have) or are you just simply trolling the new Siglent SA threads? 

[Smokey]

How long did it take to put this video together.  This one was definitely not "off the cuff".  Lots of prep it looks like.
Did you get some help with this one?

[tautech]

How long did it take to put this video together.  This one was definitely not "off the cuff".  Lots of prep it looks like.

Do the maths, this is when Dave first announced he had it:
https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/msg962513/#msg962513

Did you get some help with this one?

If you study the following posts linked above you'll see some forum members gave advice.

[PartialDischarge]

Still what makes me wonder is that many Hittite chips used in this SA are declared obsolete.

Have you never encountered this (of course you f***ing have) or are you just simply trolling the new Siglent SA threads? 

I dont think hes trolling but its nctnico and his crusade against rigol and siglent products.

[EEVblog]

How long did it take to put this video together.  This one was definitely not "off the cuff".  Lots of prep it looks like.

This one took about two days by the time I dicked around with all sorts of little stuff. Started as usual on Tuesday and wanted to release Tuesday, but had to do some family stuff and I also decided to do the new overlay thing during it. Wasn't finished and uploaded until Wed night.
Almost all my videos I shoot and edit in a day, so you could say roughly twice as long as a normal teardown.
"prep" isn't the right word, there was still essentially zero "prep", I pressed record and started yapping. Then I decided I'd try to use the photos I had and do all the teardown commentary during the edit, rather than in-camera mic work as I normally almost always do.
So the only "prep" was figuring out the blocks and drawing them all, looking up datasheets etc. Once I had all that it was my usual press record and start yapping technique. There was no script or planning what I was going to say, as with all my videos, so IMO, still "off-the-cuff".

Did you get some help with this one?

Not really. But I was talking about it on the forum and posted an early 1st guess block overlay before I wet to bed and realised I had a lot of it wrong, as was confirmed by several others. So I took another shot at it the next day going through it more carefully.

[EEVblog]

I don't believe they leave producing the 2 or 3GHz model to chance. With modern production processes you can build every unit to precise specifications. If you have different versions you'll also need different microstrip filters so you'll also need two different board designs. Taking the chance with lower spec components isn't going to cut it either. For example: there are many RF switches on the board. If some of them operate to >3GHz and some not the chance of creating a 3GHz capable SA is nearly 0. Also if demand is greater for the 3GHz model you will be left with a whole bunch of boards which you can't sell. So either all units are the same and work up to 3.x GHz or they have specific designs for the 2.xGHz and 3.xGHz models.

Yep. I'd bet my bottom dollar all units are fully speced to 3.2GHz.

[EEVblog]

Really? Do you really believe that company like Siglent do not have enough well educated and experienced RF engineers for design this kind of simply front end where is nothing special.

It makes we wonder if they have poached a designer or two from one of the biggies?, or maybe even Rigol? As I have heard that Rigol have been losing people...

Not that I'm suggesting Siglent couldn't have done this with their existing people, but to me it just seems like it had a bit more RF spit'n'polish then you'd expect from their first shot at a spectrum analyser.

[tautech]

Really? Do you really believe that company like Siglent do not have enough well educated and experienced RF engineers for design this kind of simply front end where is nothing special.

It makes we wonder if they have poached a designer or two from one of the biggies?, or maybe even Rigol? As I have heard that Rigol have been losing people...

Not that I'm suggesting Siglent couldn't have done this with their existing people, but to me it just seems like it had a bit more RF spit'n'polish then you'd expect from their first shot at a spectrum analyser.

And again we remind readers this is not Siglents first "shot" at a spectrum analyser although they haven't had one to offer in their lineup for the last year or two.
https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/msg964143/#msg964143

[Brumby]

Yes, Dave.  A good job indeed.

I found this to be not only good as a tear-down, but informative as to the nature of the beast and actual implementation of various functional blocks.

I know it's extra work, but I think it's something I would like to see more of.

[rf-loop]

, but to me it just seems like it had a bit more RF spit'n'polish then you'd expect from their first shot at a spectrum analyser.

What "first shot"?

SSA1010 and SSA3030 are predecessors for SSA3000X