Siglent SVA1015X and SVA1032X 1.5, 3.2GHz Spectrum & Vector Network Analyzers

[chicken]

Is it normal to get an ADC overload warning in VNA mode with default settings and nothing connected?

Default after pressing the Preset button is S11 with tracking gen set to -5 dBm. And that's fresh out of the box without doing a port calibration yet.

The warning goes away when dialing down the tracking generator to -7 dBm or less.

[maxi]

On my SVA1032X the VNA default settings are Tracking Generator -5dBm, Attenuator is grayed-out but shows +15dB so there should not be any overload. When I push the dynamic-range to maximum in s21mode TG -5dBm and Att 5dB it beeps from time to time but gives with 4 Averages about 100dB to measure duplexers and filters. 

[tautech]

Is it normal to get an ADC overload warning in VNA mode with default settings and nothing connected?

Default after pressing the Preset button is S11 with tracking gen set to -5 dBm. And that's fresh out of the box without doing a port calibration yet.

The warning goes away when dialing down the tracking generator to -7 dBm or less.

No.

SVA1032X open ports:
TG is activated when VNA mode is selected and levels can be set in the TG menu.


In Log Mag mode in particular the dB/div Scale can be set to fractions of a dB whereas the default is 10dB/div.
Uncalibrated screenshot:

[chicken]

Is it normal to get an ADC overload warning in VNA mode with default settings and nothing connected?

Default after pressing the Preset button is S11 with tracking gen set to -5 dBm. And that's fresh out of the box without doing a port calibration yet.

The warning goes away when dialing down the tracking generator to -7 dBm or less.

No.

On my SVA1032X the VNA default settings are Tracking Generator -5dBm, Attenuator is grayed-out but shows +15dB so there should not be any overload.

So it looks like my unit is broken out of the box? 

[tautech]

Is it normal to get an ADC overload warning in VNA mode with default settings and nothing connected?

Default after pressing the Preset button is S11 with tracking gen set to -5 dBm. And that's fresh out of the box without doing a port calibration yet.

The warning goes away when dialing down the tracking generator to -7 dBm or less.

No.

On my SVA1032X the VNA default settings are Tracking Generator -5dBm, Attenuator is grayed-out but shows +15dB so there should not be any overload.

So it looks like my unit is broken out of the box? 

Maybe not. Is yours an ex SSA unit of factory SVA ?
Hacked units can produce weird results until a VNA Cal is done.

You could try a rough bush Cal with SOL's for a Port 1 Short, Port 1 Open and a 51R Load to see if that settles it down.

Post some screenshots.

[chicken]

Maybe not. Is yours an ex SSA unit of factory SVA ?
Hacked units can produce weird results until a VNA Cal is done.

You could try a rough bush Cal with SOL's any Port 1 Short, Port 1 Open and a 51R Load to see if that settles it down.

Post some screenshots.

Not hacked (yet). Luckily I got the real thing as I was worried about support in case something goes wrong with the VNA side. It's already on its way back. I contacted Siglent NA and they also thought that port 1 of the unit is defective.

My screenshots looked exactly like yours except for the ADC warning at the bottom. Thanks for your help!

[GMJ]

Sorry, tautech, just not seeing it.  Software communications not my strong suit, maybe I'm just too inexperienced.  Most of what I see are the SSA hacks.  Don't see the SVA hacks.  Any hints?

[tautech]

Sorry, tautech, just not seeing it.  Software communications not my strong suit, maybe I'm just too inexperienced.  Most of what I see are the SSA hacks.  Don't see the SVA hacks.  Any hints?

AFAIK as Linux is not a world I dabble in, SSA option enable procedures work for SVA.

[OldVolts]

I'm also seeing -5 dBm and ADC error on an "upgraded" unit.
Manually reduce TG to -20 and all appears to work as it should.
Is this a "feature"?
Any way to override / change the defaults?
Besides TG level I'd like my cal plane to be the default.

TIA

[tautech]

Any way to override / change the defaults?
Besides TG level I'd like my cal plane to be the default.

TIA

System>Pwr On/Preset>Factory Reset

[OldVolts]

Partial joy:
TG now OK at -20, S21 still -5 with ADC error.
Can set to -20 and all well till next power cycle or reset.

[OldVolts]

FWIW FW - V3.2.2.4.0r1

[tautech]

Partial joy:
TG now OK at -20, S21 still -5 with ADC error.
Can set to -20 and all well till next power cycle or reset.

Do check you have the latest firmware installed:

FWIW FW - V3.2.2.4.0r1

Should be V3.2.2.4.0R2
https://int.siglent.com/download/firmwares/?CateIdss=16

Use Save to grab USB screenshots and post them here paying particular attention to have appropriate menus displayed so we can see your settings and replicate them if necessary.

[OldVolts]

Thanks!

FWIW FW - V3.2.2.4.0r1

Should be V3.2.2.4.0R2
https://int.siglent.com/download/firmwares/?CateIdss=16

Now confused: Says 0R2 is for 15 not 32.  Upgraded with latest 32 update.
15 R2 update specifically mentions 15 and 75 - not 32.

Use Save to grab USB screenshots and post them here paying particular attention to have appropriate menus displayed so we can see your settings and replicate them if necessary.

OK - any particular screens?

Thanks!

[tautech]

Thanks!

FWIW FW - V3.2.2.4.0r1

Should be V3.2.2.4.0R2
https://int.siglent.com/download/firmwares/?CateIdss=16

Now confused: Says 0R2 is for 15 not 32.  Upgraded with latest 32 update.
15 R2 update specifically mentions 15 and 75 - not 32.

OK sorry, missed what model you had. 

Use Save to grab USB screenshots and post them here paying particular attention to have appropriate menus displayed so we can see your settings and replicate them if necessary.

OK - any particular screens?

Totally depends on the info you are trying to show us.
Eg. If there's an amplitude error from VNA or TG stimulus settings show that menu.

[Weston]

Is Siglent planning on adding basic expected VNA features to the upcoming firmware releases?

In particular, without the ability to export touchstone files or set the VNA sweep time, the SVA1032X is little more than a toy.

I don't understand how such basic features can be missing. Its almost as if the firmware developers have never used a real VNA. 

[migsoft]

AFAIK, VNA sweep time can be set in the upcoming firmware releases.

[hendorog]

Is Siglent planning on adding basic expected VNA features to the upcoming firmware releases?

In particular, without the ability to export touchstone files or set the VNA sweep time, the SVA1032X is little more than a toy.

I don't understand how such basic features can be missing. Its almost as if the firmware developers have never used a real VNA. 

Single channel touchstone export should be close, I'm surprised it has not been released already actually.
The adjustable sweep time feature has been noted before, but not yet implemented.

[tomud]

AFAIK, VNA sweep time can be set in the upcoming firmware releases.

Maybe you know when the new firmware is planned to be released ? It's been a long time since the last firmware update, I wonder if there will be any new update 

[Weston]

I have a question (possible bug I found?) about the EMI software package.

I am taking EMI measurements through a 10dB attenuator. Based on the manual I need to set the "Ref Offset" value in the Amplitude menu to match the external attenuator.

When in normal spectrum analyzer setting the "Ref Offset" value does shift the amplitude of the plot by the correct amount. If I enter 10dB the entire curve shifts up by 10dB on the scale.

However, when in the EMI mode setting the "Ref Offset" value shifts everything, including the scale and the limit mask. This means that all the readings and the limit mask for checking EMI emissions levels is incorrect if there is any external attenuator that is corrected via the "Ref Offset" value.

Am I misunderstanding something? The behavior seems to be correct for just spectrum analyzer mode. I looked through all the options specific to the EMI mode and I do not see any alternative way to set a ref offset value. The limit masks can be shifted up or down, but that still means that all the amplitude values are incorrect with an external attenuator.

[eloso]

Hi

I used the SVA1032X Plus  in VNA mode to determine return loss of a 2.4Ghz sector antenna.  Wanting to home in on the area between 2.4 and 2.5Ghz I set the lower and upper frequencies accordingly.

A previous VNA then would have me perform SOLT calibration for this range. When trying to do this on the SVA1032X Plus it always resets the lower to 100khz and upper to 3.2Ghz with 751 points.

It doesn't allow me to calibrate between 2.4 and 2.5Ghz at 751 points. I have been using cabling and connectors more suited to lower frequencies and that seemed rather twitchy up at 2.4Ghz. Is it not possible to calibrate over a limited frequency range to decrease the intervals between calibration points ?  I have since invested in better quality cabling/connectors (ouch!) but I am still interested to know if I am missing something or if this is normal behaviour.

I'd be grateful for any info.

Thanks

Eloso


edited to remove typo

[hendorog]

Hi

I used the SVA1032X Plus  in VNA mode to determine return loss of a 2.4Ghz sector antenna.  Wanting to home in on the area between 2.4 and 2.5Ghz I set the lower and upper frequencies accordingly.

A previous VNA then would have me perform SOLT calibration for this range. When trying to do this on the SVA1032X Plus it always resets the lower to 100khz and upper to 3.2Ghz with 751 points.

edited to remove typo

Doesn't sound normal to me, unless that model SVA has some issue with small step sizes or its a FW bug.

I assume you're doing something pretty similar to this?

* Change to VNA mode
* Press Frequency button
* Press Start Freq and set to 2.4 GHz
* Press Stop Freq and set to 2.5 GHz
* Press Sweep and change points to 751
* Press Meas, Calibration, Calibrate, 1 Port and follow the procedure. Apply the Cal.

I'll ask Tautech to check on his box.

[eloso]

Yes. I just repeated the procedure with a fresh mind on a fresh day.

The behaviour is just the same - when you press calibrate, calibrate, 1-port the frequency range always resets to 100khz to 3.2Ghz.

Subsequently pressing Frequency, setting the range up again leaves no option other than to press measure, calibrate etc etc and the same thing happens again.

BUT this time, the third time around while staring somewhat exasperated at the screen I had a hunch and pressed the screen region over the "100khz" under the graph and was delighted to find a little keypad pop up which allowed me to change the start frequency. Then I could do the same with the end frequency. Now I can continue calibration without actually having to press "calibrate" again (which would reset the span).

So problem is resolved.

I don't normally use the touch screen much (don't like fingermarks!) and am bemused at the behaviour wherebye the SVA resets the frequency just by pressing "Calibrate" button.  You can call this a bug, or a feature.  Regardless, there is nothing of this in the manual and I trust it is of help to others who want to do the same thing.  I'm not very experienced above a few hundred Mhz but from how twitchy things seem to become I would have thought calibrating a VNA in the range that you intend to use it is mandatory every time.

I was going to add that my instrument started out life as a SSA but everything I have read and what I understand tells me that this couldn't be responsible for the forementioned "bug/feature".


Thanks for taking the trouble to look, and if someone else could verifiy what I have found it might be nice.

Cheers


Eloso 

[tautech]

I don't normally use the touch screen much (don't like fingermarks!) .........

You'll find a mouse is quite useful with these instruments. 

[Weston]

Has anyone actually used the EMI software package? As I previously said, it does not seem that the Ref Offset value is being correctly interpreted in the EMI mode, leading to incorrect amplitude values.

Here are two screenshots showing the Ref Offset at 0dB and 10dB. As it can be seen, only the Ref level changes. However, the expected behavior should be that the the whole plot should be shifted by 10 dBuV relative to the Y axis while the limit line stays the same. In normal spectrum analyzer mode the Ref Offset does shift the entire plot up/down by the corresponding dB value.

Am I grossly misinterpreting something, or is this actually a software bug?