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

[probe]

Quick question if I may,

Since I use my now liberated SVA1032X only for hobby purposes I'm not in the market for a professional mechanical calibration kit but for something slightly nicer then the average AliExpress stuff. I found a fairly economical mechanical calibration kit, made of Rosenberg SMA parts, on SDR-kits.net

The kit comes with calibration instructions from Kurt Poulsen OZ7OU, are made with the best intentions but not the easiest to understand for me.

The idea is to enter the female cal kit parameters under Calibration>cal Kit>User1 and the male cal kit parameters under User2
I can enter the "define open" delay of 42.3ps and no need to change C0, C1, C2 or C3 so that's all ok. But when I try to enter the "define Load" parameters the delay and Terminal Impedance fields are greyed out and there are no fields for C0, C1, etc, while the kit comes with a measured terminal impedance and the instructions to define CII as 5pf.

Any idea how I can enter the calibration parameters?

Link to the instructions: https://www.sdr-kits.net/documents/Rosenberger_Female_Cal_Standards_rev5.pdf


 

[hendorog]

You can't change the impedance of the load on the SVA. I think the greyed out options are saying 'not yet implemented'
Therefore the load is assumed to be 50ohms for a user entered cal kit.

As an aside, for the pre-defined cal kits I believe that data files are used instead of a C0,C1,C2 etc parametric model.
But there is no built in way for an end user to use that system for a user defined cal kit.

The only way to use all of the provided params is to export the sweep data to a PC and do the calibration there.

[DL4JY]

The only way to use all of the provided params is to export the sweep data to a PC and do the calibration there.

Hello,
any suggestions what software to use ?

thanks,

Jueergen

[Bicurico]

You could just use the relevant SCPI command and forward the output to a CSV file and then import the data do Excel.

[trampas]

I was using my SVA1032X and found when I turn on min/max or averaging traces there is no way to "reset" the traces which makes it hard to connect probe and then start the min/max, has anyone else seen this, am I missing something?

Additionally I found that there is no way to freeze screen, ie stop.  For example I am probing with min/max on and then need to release the probe and save waveform, but it does not appear I can do this. Anyone have suggestions on how to stop and freeze the system?

I am also looking at trying to do impedance measurements with the SVA, it looks like it should be possible and was wondering if anyone has done this and might have a python scripts for such a feature?

Thanks

[antenna]

I was using my SVA1032X and found when I turn on min/max or averaging traces there is no way to "reset" the traces which makes it hard to connect probe and then start the min/max, has anyone else seen this, am I missing something?

Additionally I found that there is no way to freeze screen, ie stop.  For example I am probing with min/max on and then need to release the probe and save waveform, but it does not appear I can do this. Anyone have suggestions on how to stop and freeze the system?

I am also looking at trying to do impedance measurements with the SVA, it looks like it should be possible and was wondering if anyone has done this and might have a python scripts for such a feature?

Thanks

When I want to reset, I just tap "Clear Write" and then go back to max or min or average.  If you tap "view" (underneath Min Hold in the trace options), that holds the screen as is and allows you to release the probe and do whatever.

And, of course, it does do impedance measurements...  Just press the mode button (one of only two made of transparent silicone, although I've never seen it lit up green like the TG button) and select "vector network analyzer". Be sure to do your calibration though.

[tautech]

I was using my SVA1032X and found when I turn on min/max or averaging traces there is no way to "reset" the traces which makes it hard to connect probe and then start the min/max, has anyone else seen this, am I missing something?

You're overlooking the type of trace required/selected for each task and the type of detection required.

Additionally I found that there is no way to freeze screen, ie stop.  For example I am probing with min/max on and then need to release the probe and save waveform, but it does not appear I can do this. Anyone have suggestions on how to stop and freeze the system?

In the Trace menu use the View option that ceases the sweep and freezes the trace, permanently until you select one of the other Trace options or reclick on the type you were using to start the sweep again.

Below is a quick selection of screenshots displaying some various menus showing preferred settings and some captures of 100-120 MHz 0dB sinewaves from my SDG6022X
Trace A is the only one not displaying it was 10x averaged and Trace B was to be Max Hold but I must have made some error. 

Hope these are of help to get you better acquainted with the capability of the SVA's.

Further excellent basic use guidance screenshots are early in the SSA3000X thread:
https://www.eevblog.com/forum/testgear/siglent-ssa3000x-spectrum-analyzers/msg958295/#msg958295

[trampas]

Thanks for the information!

I am still learning about RF and using the VNA. 
I wanted to measure the impedance of piezo probe.  So I setup the VNA on S11, Smith chart R+jX, and got the enclosed smith chart.

I then saved the CSV and created a linear graph.   

This was not what I was expecting so I connected up a MSO5354 scope and did the measurements using a reference resistor.

I did not calibrate the system, but the curve shape matches what I was expecting.  Note using another resistor as reference shows that the measurement has some frequency error most likely due to the cables I am using, but the curve shape matches my expectations.

I was wondering if anyone had a reason that the VNA would not be giving me a similar impedance curve?   

Thanks

[RoV]

I wanted to measure the impedance of piezo probe.  So I setup the VNA on S11, Smith chart R+jX, and got the enclosed smith chart.

The two curves are not so different... did you calibrate the VNA? In case you didn't, is it a true SVA1032 or an upgraded SSA? I ask because the SVA1032 has a builtin calibration that I expect to work acceptably well at such low frequencies, unless you use very long cables; on the contrary, the SSA normally doesn't have it and the error can be very large.

[trampas]

It is a SSA3021X plus hack/upgrade and I did calibrate with short/open/50 Ohm load.   I also tested the VNA with 100 ohm and 50 ohm resistors to make sure the impedance was reasonable.

The frequency range is up to 10Mhz, hence the cabling will make a small difference but using 6" SMA RG316, I doubt it is significant.

I actually got the magnitude and phase graphed, for the VNA:

I also have it done with an O-scope and signal generator.
Forgive me for not labeling axis on graphs. The phase Y axis is degrees, the X axis is frequency in Hertz.

This is the same piezo element.  I estimate the scope could be as much as 6 ohms & 12 degrees off based on running a test with a 50 ohm load. The o-scope is done with BNC alligator cables which have more capacitance.   

One of the things with the piezo is looking for the resonate frequency, which is typically the point where the phase is closest to zero.  In the O-scope version this matches what I was expecting and is at ~8.25Mhz, while the VNA shows to be at 8.5Mhz which is a significant difference.   A second issue I wonder about is that from what I have read the resonance frequency should have the lowest impedance, which does not match the data. 

I guess the next thing is to create some known complex impedances and measure them, like an RLC circuit.   

Overall it is a blast to learn new things, and I am having great fun. 

[dmowziz]

The SVA1015X or alike

Please in VNA mode, is it possible to change the IF Bandwidth?

I searched the thread concerning IF bandwidth but could not find anything (strangely)

Thanks

[RoV]

The SVA1015X or alike
Please in VNA mode, is it possible to change the IF Bandwidth?
I searched the thread concerning IF bandwidth but could not find anything (strangely)

Not yet: option is present under the STIMULUS menu, but fixed (grayed) at 10 kHz on the SVA1032X with FW V3.2.2.5.1R1, and I imagine is same is true for the 1015.
Really can't understand why.

[RoV]

It is a SSA3021X plus hack/upgrade and I did calibrate with short/open/50 Ohm load.   I also tested the VNA with 100 ohm and 50 ohm resistors to make sure the impedance was reasonable.
I actually got the magnitude and phase graphed, for the VNA

I have simulated a simple resonator model, series RLC plus a shunt capacitance, normally used for piezos close to resonance. I have tuned the component values to get an S11 shape similar to yours. The Z11 resembles more your scope plot rather than your VNA Z plot, so I suspect you made some mistake in the S to Z transform.

One of the things with the piezo is looking for the resonate frequency, which is typically the point where the phase is closest to zero.  In the O-scope version this matches what I was expecting and is at ~8.25Mhz, while the VNA shows to be at 8.5Mhz which is a significant difference.   A second issue I wonder about is that from what I have read the resonance frequency should have the lowest impedance, which does not match the data. 

The external capacitive loading lowers the resonance frequency. In the case of the VNA it is compensated by the calibration, so there is no excess capacitance if you calibrated on the DUT plane. In the case of the scope you may have a few 10s to 100 pF of additional shunt capacitance.

The series RLC1 block has a minimum real impedance of R at the series resonance frequency of the intrinsic resonator, but, due to the presence of C1, phase is a bit negative there, around -47°, and the real part of impedance is slightly lower than R. In this specific case phase reaches the minimum of -9° at an higher frequency, where R is transformed to an higher value.

[profanum429]

I recently purchased a fresh SSA3021X+ that is now a newly minted SVA1032X so I'm pretty happy about that.

I was able to borrow a decent Spinner 3.5mm cal kit, add it, calibrate, and get a good calibration on the VNA portion and do some simple measurements.

I'm looking at purchasing my own (cheaper) cal kit and figured the Siglent ones were a good place to start. I've almost settled on the F603FE as a good budget compromise but I was wondering where exactly the calibration coefficients (or CSV for S-parameters?) stored for these kits? Mostly interested since all the other kits I've used in work (some Spinners and some Maury Microwave kits) come with the coefficients or the data files to load versus having it already in the system.

I found the /usr/bin/siglent/usr/vnacalkitdata but it seems to be a sort of mix of different standards and if I'm reading the .csv right, all of mine end at 1.5GHz? Is there another spot that I can't seem to find or is this an artifact of the conversion process to the SVA? Just wanted to make sure before I purchase I won't end up with a weird half-way there calibration setup.

[tautech]

Okay chaps, I may have found a bug. 

SVA1032X
VNA mode, Mag Loss.
Save a TRC (Trace) file to be used as a reference trace so to be recalled which these instruments if we are to believe the user manual can do.
https://int.siglent.com/u_file/document/SSA_XP_SVA_UserManual_UG0703P_E02A.pdf
8.3 File P139

First screenshot is how I want to use a stored TRC file, that is display it from memory to compare with a live/active trace.
Can't seem to make it work and save a TRC file to internal or USB memory.
TRC is not always available to select as a Save or View filetype.
Is it Mode dependant ? If so why ?

Unreasonable expectation, I don't think so. Opinions please ?

[Bicurico]

Are you using the same start/stop frequencies and number of points? If these are different it only makes sense that the saved file won't open.

I don't own this device, so I can't test, but my own software uses a similar feature with this exact limitation

Regards,
Vitor

[tautech]

Are you using the same start/stop frequencies and number of points? If these are different it only makes sense that the saved file won't open.

I don't own this device, so I can't test, but my own software uses a similar feature with this exact limitation

Regards,
Vitor

Can your older SSA3kX save and recall a TRC (Trace) file ? That's the only issue this end.
Once recalled according to the manual it will be displayed at the settings when saved.

The screenshot only shows why I need to recall a previous trace so to compare any previous measurement against a live one.
This feature seems not to work as one would imagine and it needs be sorted especially for the portable SHA800A coming as this will be used in the field with such a device.

[Bicurico]

It seems to work fine on mine. The yellow trace shows the TG dirrectly connected to the input with normalization.

• Saved the trace as TRC.
• Loaded the trace back on A - it gets into VIEW mode.
• Inserted a band-pass filter(used by CATV operators to remove unsubscribed channels).
• Activated trace B to VIEW.

You can now compare both traces.

I think you assumed that the TRC file will be like a background image - that is not the case. It is read as a trace and obviously kept in VIEW mode (otherwise the sweep would overwrite it).
When loading the TRC, it will set the relevant START/STOP frequencies, as I expected.

Regards,
Vitor

[tautech]

Thank Vitor and yes I can save a TRC file in SA mode. It's been on my mind for most of the day and your post kicked me into trying it.
200MHz sinewave from SDG6022X saved as a TRC, reloaded onto display and trace B enabled to display a now 190MHz sinewave. 
So it works as expected in SA mode so it's time to dig deeper why it won't in VNA mode as it needs to especially if we were to take it into the field to check an antenna that might not be performing correctly compared to a previously saved sweep.

Attached are the screenshot of the TRC (trace A View) and the live 190 MHz trace B and the TRC file with a txt extension added so to be able to upload it here.

Yet it won't work in VNA mode ! 
I'll be chasing this up again with Siglent on Monday.

[ormandj]

Don't be so hasty as we need check this out first.
Yes datasheet says VNA stimulus now = higher BW models but there are also other error in the datasheet in spec for all models.

No hastiness here, just thinking out loud.

Nonetheless, I remember who has indicated in the past the low freq. distinction as a sign that the HW should be different.

Yep, of course and it's very likely the inbuilt bridge was swapped out however if you hunt through the datasheet there are still a # of differences to the 3.2 GHz model including weight = lesser HW. 

But when the # of VNA data points are wrong by an order of magnitude it screams someone is not doing their job ! 

Fresh arrival.
100 KHz is certainly the minimum stimulus frequency that can be set.

Still waiting for official confirmation......

Did you ever hear anything back? Was the HW improved to support this lower frequency operation? Thank you!

Quick question if I may,

Since I use my now liberated SVA1032X only for hobby purposes I'm not in the market for a professional mechanical calibration kit but for something slightly nicer then the average AliExpress stuff. I found a fairly economical mechanical calibration kit, made of Rosenberg SMA parts, on SDR-kits.net

The kit comes with calibration instructions from Kurt Poulsen OZ7OU, are made with the best intentions but not the easiest to understand for me.

The idea is to enter the female cal kit parameters under Calibration>cal Kit>User1 and the male cal kit parameters under User2
I can enter the "define open" delay of 42.3ps and no need to change C0, C1, C2 or C3 so that's all ok. But when I try to enter the "define Load" parameters the delay and Terminal Impedance fields are greyed out and there are no fields for C0, C1, etc, while the kit comes with a measured terminal impedance and the instructions to define CII as 5pf.

Any idea how I can enter the calibration parameters?

Link to the instructions: https://www.sdr-kits.net/documents/Rosenberger_Female_Cal_Standards_rev5.pdf

To be clear, are you saying you cannot set c0/c1/c2/c3/length for open, l0/l1/l2/l3/length for short, and load impedance to suit your calibration kit? Or that you can not set load impedance, but the rest are possible? I have a few Anritsu calibration kits I'd like to use (such as OSLNF50A-8), so have the actual measurements/values.

[antenna]

Does anyone know if there is a way to get a normal graph of S11 (not polar or smith) of resistance over frequency on the SVA1032x?  I have been trying to use it to look at the negative resistance at the base of a colpitts oscillator vs frequency and the polar plot is not nice to look at.

Thanks!

[ormandj]

For those curious about the user defined calibration info, I went ahead and purchased one, and you can enter delay (time or length, all units like mm/m/etc) and C0-C3 for open and short, and load is indeed fixed, you cannot change the delay or impedance. Through you can change the delay.

[Crambone]

Can this hack be used on the SSA3015x plus ? I was told the hardware is exact, is this true?

Andrew

[tautech]

Can this hack be used on the SSA3015x plus ? I was told the hardware is exact, is this true?

Andrew

Same as what ? Same as SVA1015X, I believe so.

[danmc]

I'm having a terrible time interfacing with the SVA1032X over USB.  It is quite frustrating as I have some testing I'd really like to automate.  I'm using python and the python-usbtmc package.  What I'm seeing is that not only do I get unreliable communication but I get a lot of duplication.  To be more concrete, here is a simple example:

import usbtmc

# create the instrument
sa = usbtmc.Instrument(idVendor=0xf4ec, idProduct=0x1301)

# reset
sa.write("*RST")

# using try/except because half the time it fails with an exception
for i in range(10):
    try:
        r = sa.ask("*IDN?")
        print(r)
    except:
        print("FAIL")

# can repeat with ":SYST:DATE?", ":SYST:TIME?", ":SYST:LANG?" and not only does it fail often
# but I routinely get the result from a previous command instead of the one I just issued.


As a note, the same code but with a different idVendor and idProduct to point at some Keysight and also Rigol stuff has no problems.  It just zips through giving expected results.  I also tried on a Siglent arbitrary waveform generator and not only was "*RST" not accepted but I had the same unreliable results with "*IDN?", "SYST:DATE?", etc.

Any suggestions?  I'm pretty frustrated that this isn't just rock solid as computer control is just expected on equipment.

Thanks
-Dan