Siglent SSA3000X and SSA3000X-Plus Spectrum Analyzers

[Orange]

I noticed a while back that my 3032X and someone else's 3021X running 1.2.8.5 that signals at -125dbm are about 2db lower than what they should be and at -135dbm its over 10db lower when RBW is 3Hz or 1Hz. 10Hz RBW and wider show the correct level.
If the answer is in AN-150 I just don't see it.

Vidas  N8AUM

Something wrongly implemented in the firmware for the 1 and 3Hz RWB. Siglent perhaps need a push to look at it. See also
https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/msg1300942/#msg1300942
Which also mentions a strange behavior. Perhaps all of this is because of the resolution of the ADC in combination with 1 or 3Hz RBW (FFT error ?)

[N8AUM]

Hello all, can someone in layman's terms explain what I am seeing and why?
TG output set @ -20dbm, input att set at 20db. Yellow trace was normalized with a good quality JFW attenuator on input. Cable is 20" long of from a batch of M17/128-RG400 MIL-C-17. When I remove the attenuator from input I get the "ringing" and same thing with the other 6 cables.

Thanks in advance 
N8AUM  Vidas

[1design]

What you see is the return loss of one of your components, have you tried doing the same measurement without normalization?

[Orange]

Hello all, can someone in layman's terms explain what I am seeing and why?
TG output set @ -20dbm, input att set at 20db. Yellow trace was normalized with a good quality JFW attenuator on input. Cable is 20" long of from a batch of M17/128-RG400 MIL-C-17. When I remove the attenuator from input I get the "ringing" and same thing with the other 6 cables.

Thanks in advance 
N8AUM  Vidas

This could be the cable or attenuator, or a blown SA input, (not 50 Ohns any more)
Post a picture of only the cable and TG on -20dB, and SA attn on 20dB. Is the ringing gone ? (it should be)

If you did not get the ringing, do a normalization

Insert the attenuator and observe (ringing means = bad attenuator)


My bet is the cable

[rf-loop]

I'm not surprised. More I would be surprised if I could not see something more or less similar.

This cable is 50 ohm +2ohm
"JFW" and "good quality" - what it means?  They have several models and quality grades.  What is attenuator model exactly so we can check data sheet.
(these may have example some VSWR as example 1.2 to 1.4  if they are specified to example over 3GHz)
Then there come cable and its connectors, also these are not ideal components.

Nothing is exactly 50ohm pure impedance over 0 - 3.2GHz.

SA input also: RF input VSWR  ( input attenuation 10 dB),
1 MHz~3.2 GHz  <1.5, nominal

TG output impedance accuracy not specified.

Reflections, standing waves. This is not ideal world from simplified books, this is practice in real world.
Small note also: You remove attenuator, also it need note that transmission line length change and it affect because impedance is not at all perfect. More fun is coming if you go to ten times more high frequencies and things start show real magic.
Also when we use attenuators and cables many many times they change - cable bent and twisted several times, connectors wear and so on.  Drop attenuator once to hard floor and write its calibration table again. and so on.

[tautech]

I'm interested in building a reflection bridge and was wondering which toroids you used in your design?

Google this: directional coupler design
Reflection bridge, directional coupler, power dividers......all much the same thing.

[whalphen]

Sorry,  I must have clicked the wrong link.  My question is intended for TurboTom in response to his message #456.

[rfspezi]

I am a bit frustrated concerning the spurious issue that seems to affects several units.

https://www.eevblog.com/forum/testgear/siglent-ssa3032x-input-related-spurious-99091/msg1397013/#msg1397013

[videobruce]

Seems like the interest for this has died off.
No F/W updates for 3 months especially for doing manual B/W adjustments that keep decreasing sweep speeds no matter if the B/W settings are increased or decreased.

With all the talk about the problems with 'spurs', I can only assume the above is not their priority even thou it was reported some time back and confirmed. 

[Dubbie]

One feature I find really frustrating is that markers dont stick to the spectrum.

If you zoom in or shift the frequency, the markers stay in the same place on the screen and don't track the frequency.

Very very annoying.

[videobruce]

I think that is typical of most/many SA's IIRC.

[srce]

Are there any high impedance probes that can be used with the SSA3000X?

[technogeeky]

Are there any high impedance probes that can be used with the SSA3000X?

Any probes that don't require electronic communication to configure themselves will work (so this is most of them except the very latest models). You will have to provide a power supply to the probe, since it appears the Siglent doesn't provide it.

[ghan]

Does anyone know if there is a Reflect Bridge that is at least 2.4GHz? Also would fit for this Siglent Model SSA3032X. Siglent only has a Reflect Bridge ranging from 1MHz to 2GHz.

[mv]

Seems like the interest for this has died off.
No F/W updates for 3 months especially for doing manual B/W adjustments that keep decreasing sweep speeds no matter if the B/W settings are increased or decreased.

I'm also disappointed by the lack of more FW updates. I was hoping for more measurements to be added (harmonic distortion, phase noise) among other things. No luck here. My unit costed 3000 € plus TG option plus shipping. Too expensive for such a short support period.

[rf-loop]

No F/W updates for 3 months especially for doing manual B/W adjustments that keep decreasing sweep speeds no matter if the B/W settings are increased or decreased.

I have now used this SA after it have first time be available.
I have never meet this problem what I do not even understand what you mean.
I have adjusted RBW's up and down and always sweep speed follow logically up and down automatically (until I force sweep speed to  - manual mode - what operation seems to have little development needs)

Please can you offer perfect description including all details so that this feature can repeat.
I have tried something like adjusting span, frequencies and with these many setups then changed RBW (what is B/W adjustment? you mean. There is RBW and VBW if you mean filters width)
Also tell if some settings are set for force auto or manual mode on when this happen what you try to tell.

Least I want repeat it and see what kind of problem it is and in what situation exactly it exist.

[Ghislain]

Depending upon what you want to achieve, you may want to have a look at using a directional coupler. These come in a various frequency ranges, well up into several 10's of GHz and can easily be found used (Narda is one particular manufacturer to look out for).
And of course they can without any problem be used with your SA 
W2AEW has an excellent video on how directional couplers can be used here:


 

[Gonzini]

Hi guys
Just picked up a 3021x.
Seems pretty good so far but just scratched the surface.
Wondered if there was a way to turn off the time limited measurement functions and re-enable when needed?
Couldn't see a setting for that in the menu.
Is it just done on run time so once the 48hrs is up that's it?
Had a quick search though this thread but didn't spot anything in regards to that. (or even looked at the manual yet....)
Cheers

[rf-loop]

Hi guys
Just picked up a 3021x.
Seems pretty good so far but just scratched the surface.
Wondered if there was a way to turn off the time limited measurement functions and re-enable when needed?
Couldn't see a setting for that in the menu.
Is it just done on run time so once the 48hrs is up that's it?
Had a quick search though this thread but didn't spot anything in regards to that. (or even looked at the manual yet....)
Cheers

Start reading here
https://www.eevblog.com/forum/testgear/hack-of-sigllent-spectrum-analyzer-ssa3021x/msg1132969/#msg1132969

and then continue reading, read and look carefully until you know (also it is good to perhaps filter some things because some small things have changed after some more new firmwares but still principle is same. Remember copy and keep safe some important original files!!  This all must do with this order: First brain then muscle. If not sure what and how to do then do not until all is enough clear.

[Gonzini]

Hi, cheers for the reply.
Not going to hack it yet, only just got it today. Just wondered if there was an option to temporarily disable the timer by turning off the demo functions and enable as needed.
I guess its not possible as doesn't work like that.
Looks a bit involved that hack, also its on a later firmware than described.  V1.2.8.5a. I will have a read through the posts though out of interest.
I think I'm going to miss the Advanced measurement kit most, probably won't miss the others. T.G came with it. Might wait for a deal on the measurement kit in the future if it comes up. Quite like to keep the 3 year warranty without the concern to get it back to factory.
I'm sure it will remain very usable without it, just the windup of the measurement button not working or a taunting message...
I have on the other hand unlocked the Rigol DS1054z 
Cheers

Just had a read through how the hack works, that's pretty cool..

[seronday]

No F/W updates for 3 months especially for doing manual B/W adjustments that keep decreasing sweep speeds no matter if the B/W settings are increased or decreased.

I have now used this SA after it have first time be available.
I have never meet this problem what I do not even understand what you mean.
I have adjusted RBW's up and down and always sweep speed follow logically up and down automatically (until I force sweep speed to  - manual mode - what operation seems to have little development needs)

I have found this issue as well, when configuring the spectrum analyser to work with an external sweep generator.

When Manual sweep time is selected, manually changing the resolution bandwidth or video bandwidth will change the sweep time.
For example, reducing the RBW will slow the sweep speed.
After that increasing the RBW slows the sweep speed some more.
If the RBW or VBW is continually changed Up and Down, the sweep time just keeps getting slower.

Several other issues have also shown up.
1. With FW ver 1.2.8.5a,  In the Amplitude menu when the Units are changed from dB to anything else, the vertical scale does not
   change. Only the Reference Level text changes to reflect the new Units.
   Previously the Vert Scale did change to show the selected units.

2.  In Zero Span mode, at frequencies below 9.3Mhz, the Tracking Generator level increases by approx. 2.5dB.
     When sweeping, this increase in level does not occur.

Regards.

[rf-loop]

No F/W updates for 3 months especially for doing manual B/W adjustments that keep decreasing sweep speeds no matter if the B/W settings are increased or decreased.

I have now used this SA after it have first time be available.
I have never meet this problem what I do not even understand what you mean.
I have adjusted RBW's up and down and always sweep speed follow logically up and down automatically (until I force sweep speed to  - manual mode - what operation seems to have little development needs)

I have found this issue as well, when configuring the spectrum analyser to work with an external sweep generator.

When Manual sweep time is selected, manually changing the resolution bandwidth or video bandwidth will change the sweep time.
For example, reducing the RBW will slow the sweep speed.
After that increasing the RBW slows the sweep speed some more.
If the RBW or VBW is continually changed Up and Down, the sweep time just keeps getting slower.

Several other issues have also shown up.
1. With FW ver 1.2.8.5a,  In the Amplitude menu when the Units are changed from dB to anything else, the vertical scale does not
   change. Only the Reference Level text changes to reflect the new Units.
   Previously the Vert Scale did change to show the selected units.

2.  In Zero Span mode, at frequencies below 9.3Mhz, the Tracking Generator level increases by approx. 2.5dB.
     When sweeping, this increase in level does not occur.

Regards.

Ok, now I can see this problem.
Problem is that when user set Sweep time manual (what means user want force it for some fixed sweep time) it do not stay locked to user set sweep time. When user force it for manual sweep (for what? )  time it need stay with this user selected speed independent of what other settings user after then change.

But so or so and for what ever reason someone need (or use it without real need)  this "force to fixed speed" (manual sweep speed) of course this need repair. It is there and it need work. Just so that if you set manually say example 100ms  sweep time it then stay with this speed independent of what ever other settings user  change - until he set it back to auto or change this manual speed.
When manual speed is wrong for measurement accuracy it need only turn "UNCAL" indicator on (always when user set speed is too high)

[leix_99]

I notice that with the input terminated with 50 ohms and the unit at the factory preset, power on settings there is a 5-10dB slope rising from 0 Hz to 2.1 GHz.  Is there a setting to correct this?
In general I would like to store a trace and then subtract it from another stored trace or the current input trace.  Is this possible?  If so, how?

Base noise can not correct to flat. (oh well... it "can" but then we loose most important things, signal level flatness what is real important. )

It is natural and quite common in spectrum analyzers that base noise level rise when we go to higher frequencies.

This do not affect signal level  accuracy. It is corrected by internal flatness table (1) -  for every single individual SA (this is done by factory and this is one important part of factory calibration data (discussed also in some "hack" threads.
Also PreaAmplifier flatness is corrected so that measured signal levels are in specifications. And as can see it also produce bit different base noise.  If we look more carefully this base noise it have quite complex shape with many hills and valleys.

This is one individual SA noise floor but other SA may be some amount different.

SSA3021X (previously in this thread:"Reply #212 on: June 18, 2016, 11:54:05 AM" )

Do not worry it is not flat. (as long as it is inside specs.)


SSA3000X DANL





Edit/add: Keysight N9320B DANL specs.


(1) every SSA3000X have after factory calibration process individual level and flatness correction table. It is in folder "calib". 
Example every 52 attenuator level (0-51dB) have its own 8kb level correction table. Also, there are many other factory cal data.

I know this reply dates quite a while, but I received my SA last week and it "seemed" to be a previously used/returned unit (no screen plastic, really small dent on the casing).

After unpacking the unit, noise floor curve looked quite higher than the average ones I saw in videos/reviews but the image you posted makes me think there's something wrong with my SA.

I've used the same parameters you used to do a 2.1gig sweep, RBW/VBW 1kHz, all traces average (same colour/trace per measurement), sweep mode "sweep" and input 50ohm terminated. Check this out:

 

Also, the TG flatness (which I think it should be somewhere less or around 3dB) is quite off to. I'm not that concerned about that since the cables I had lying around are long and old but still, I have a bad feeling about this particular unit...

Has anyone had a problem like this with Siglent instruments?

[Performa01]

Seems like rf-loop has some particularly good specimen of this analyzer - maybe some early hand-crafted/polished prototype

If I look at your measurements @ 2.1GHz and compare it to the specifications, then I get this:

RBW=10kHz, Preamp=on Measured: -119dBm; Specified: <-115dBm, typ. -118dBm; >typ.
RBW=10kHz, Preamp=off Measured: -101dBm; Specified: <-95dBm,   typ. -99dBm;  >typ.
RBW=1MHz,  Preamp=on Measured: -98dBm;   Specified: <-95dBm,   typ. -98dBm;  =typ.
RBW=1MHz,  Preamp=off Measured: -80dBm;   Specified: <-75dBm,   typ. -78dBm;  >typ.

As far as I can tell your unit is not only within the guaranteed specifications, but also meets or even exceeds the typical ones.

[rf-loop]

I know this reply dates quite a while, but I received my SA last week and it "seemed" to be a previously used/returned unit (no screen plastic, really small dent on the casing).

After unpacking the unit, noise floor curve looked quite higher than the average ones I saw in videos/reviews but the image you posted makes me think there's something wrong with my SA.

I've used the same parameters you used to do a 2.1gig sweep, RBW/VBW 1kHz, all traces average (same colour/trace per measurement), sweep mode "sweep" and input 50ohm terminated. Check this out:

 

Also, the TG flatness (which I think it should be somewhere less or around 3dB) is quite off to. I'm not that concerned about that since the cables I had lying around are long and old but still, I have a bad feeling about this particular unit...

Has anyone had a problem like this with Siglent instruments?

I think it need look bit more deeply. 
I have one concern from what I see in your image. But I do not tell it yet before some further knowledge about your individual unit. (these traces are still in specs but....)

But first I need know do you have any reliable trusted signal source, pure sine wave and  example between 5 - 50MHz what level you really KNOW so that absolute error is least less 1 dBm. Something between -30dBm to 0dBm.

Measure some these known level signals with SSA and note if level error is inside this method reliable limits or clearly outside.


And note, RF input is extremely sensitive for EOS/ESD and it happen easy! You do not feel any "static electric" and still it can be damage level. This is common to all, not for just you.

Even if you do not have reliable known level source:


1.


Set  factory defaul. RF input terminated
Set trace A Clear write
Set trace D Clear write
Set Detector Trace A: "Average Log Pwr"
Set Detector Trace D: "Pos Peak"
Set RBW=VBW=10kHz
Set Attenuator 0dB
Set Ref level -50dBm

Take this kind of  image, SA continuously running






2.


Set SA for factory preset (defaults)
Connect SSA own Ref Out (10MHz) to RF input.
Set Atten 30dB
Set Ref level +10dBm 
Set center Frequency 10MHz
Set RBW 300kHz
Press  Peak (marker show now peak value, note this value)

Take this kind of image, SA continuously running

Then if you want at this time do more
Set factory defaults
connect again 10MHz ref out to RF in.
Set center freq 10MHz, Span 10kHz (I believe you see 1kHz RBW)
Set attenuator 30dB and reference level +10dBm
Press Peak and select also in this menu Cont Peak ON
Note marker level
Press System
In this menu select Calibration
There open selection AutoCal  and it is "Close"
Turn it "Open" and note how much your marker level change.
Write down "Open" value and "Close" value of marker level.
 
Tell these both values.