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On Tue, Jul 27, 2021 at 01:24 PM, Reginald Beardsley wrote:

In what domain are the filters implemented? What are the coefficients for the operator?

Reg,
? ?See the following Wiki page??

? ?The?tinySA resolution filters are digital FIR filters implemented as DSP code inside the RX SI4432 so its probably best to download the datasheet for that chip to get a detailed description of their algorithm.? I'm not certain how much of that information is proprietary.

? ?The filters are selectable via a register location within the?RX SI4432.? Not much more can be done with them beyond that.


Herb

I sent them an email asking if their package worked on Linux.? Hopefully it will be so.? If not, is there no other way to compile it for Linux with another compiler?? I have compiled a program once before, but at the time, I didn't know that that's what I was doing.? I don't know anything about programming, but I can follow some instructions.? It would be great if we Linux users could have the apps too.? Thanks.

Yes I continue slowly.? Progress is glacial compared to Erik :)
To be clear to others, the simpleSA version runs on a different processor (ESP32) and the initial motivation was to see if I could make an analyser that could be used and controlled via the web from a standard internet browser using the WiFi features of the ESP32.? It proved to be possible though it took a few months to work out why the wifi stopped at certain points in a sweep - turned out the fifth harmonic of the LO was blocking the WiFi receiver!

I also designed a set of PCB, using KiCAD.? Of course there were a few mistakes but easily fixed.? My boards are a little more cramped than Gyula's as I wanted to keep the two boards within the 100x100 for low cost PCB from JLCPCB, and I wanted all the connectors on one edge.? ?I have some of the 30MHz Si4432 clock getting in unfortunately.? The 350MHz low pass filter also needs some optimisation.? As another learning exercise I also designed a 3D printed case with cover/tilt stand using TinkerCAD?which a club member kindly printed for me.

In this build I used different frequency SAW filters and different IF for the second pair of Si4432.? With no cable connecting the TG output to the SA input you cannot tell if the TG is on or off even with RBW @ 2.6kHz.? An additional RF switch is also included to change from the low frequency range input to the high range input.

Photo below with the tracking generator being used to measure a QRP-labs bandpass filter for 20m.

I am thinking of designing another PCB set with a common clock source for all four Si4432, and where the Si4432 would be soldered directly to the PCB rather than use the ready made modules.? Not sure if buffering is needed for the clock yet and having trouble finding a low cost 30MHz TCXO - any sources anyone?? Given the limited frequency resolution maybe a TCXO is overkill.
Next plan for software development is to enable the second set of Si4432 to be used as a second SA channel, then it could be used either a two channel SA, SA with tracking generator, SA with signal generator or two channel signal generator.? It will happen when I have the need for it!

Thinking of the TinySA itself and tracking generator, with two TinySA I think a very good result could be obtained if rather than using the LO from one to synchronise the second the PC software was used to offset the IF of the two devices, and the PC software kicked off each sweep in both devices to keep the synchronisation between the signal generator frequency and the analyser sweep.? I think it should be possible to keep the two devices in good enough synch throughout one sweep just by careful timing calculation (no of samples, delay duee to filter settling, some overhead and a margin for some timing error.? Then no additional hardware such as attenuators and amplifiers would be needed.

Worth a try anyway.? Gyula's version is getting very good results with the same SAW filters in each pair and an offset in the IF but still within the passband of the SAW filters.


73

Dave M0WID

In what domain are the filters implemented? What are the coefficients for the operator?

I spent my career doing oil & gas DSP.

Reg

On Tue, Jul 27, 2021 at 09:44 AM, OneOfEleven wrote:

....? when I started writing NanoVNA-App I only thought I was writing a simple test app for my own use.

Cathy,??
?That "simple test app" has evolved into one of the best open source software applications available on GitHub.? Hopefully some other enterprising developer with your software skills and the time to devote to continued development will take up the mantel.

? Regardless, we are thankful to you for your contributions to both the tinySA and NanoVNA user community.? Stay safe and good fortune to you in the future.

Herb

I haven't tried compiling NanoVNA-App or TinySA-App for linux or MacOS myself, only for windows. To compile for the desired OS I think you just need to download the correct version of the development package I used?

You have to enter your personal details to download it but they do let you use it completely for free. Looking at the web page it's now saying it's for windows and mac-os, it used to be for linux as well, not sure anymore. I should really have used the free QT C++ development package instead, but when I started writing NanoVNA-App I only thought I was writing a simple test app for my own use.

On Mon, Jul 26, 2021 at 05:30 PM, Jason Ringas wrote:

Am I understanding correctly that the tinySA-App can be compiled to run on Linux?? What would that entail?? Could we go one step further and make it into an Appimage?

Jason,
? The topic you are referring to was a conversation between Erik and OneOfEleven, the original developer of NanoVNA-App, of which tinySA-App is a branch.? NanoVNA-App and tinySA-App are written in C++ so according to OneOfEleven, "you can install that OS's version of the development software (c++ builder) and compile TinySA-App program to work directly in the OS of choice".

? OneOfEleven privately sent her code to Erik with the caveat that it was not to be publicly distributed.? Erik's development system is Windows so he does not have the software tools to attempt a cross development of tinySA-App to Linux or MAC.

? OneOfEleven recently publicly released her NanoVNA-App source code at? ?so possibly Erik could now also publicly? release his tinySA-App branch for users of other operating systems that want to help compile the application to run natively on their environment.

? Alternatively, NanoVNA-APP supports both the NanoVNA and tinySA so, if you have the proper development tools,?you could first try to cross compile OneOfEleven's public release to Linux and let Erik know if you are successful or not.

Herb
? ?

Am I understanding correctly that the tinySA-App can be compiled to run on Linux?? What would that entail?? Could we go one step further and make it into an Appimage?

Well - maybe they ARE there after all.? If I click the "Download all files" button in the top right corner, it downloads a zip file which DOES include the STP files (along with the STL and photos).? Still doesn't show my edit to the verbiage, though...

I just uploaded the STP files to the listing in Thingiverse.? For some reason, editing a "thing" there doesn't always show the updates right away, so if you visit the link and don't see the STP files (or the "EDIT 7/26/21" verbiage in the thing details section), give it some time.? If it still hasn't updated by later this afternoon I will try again.? The edit show up when I go back and try to edit again, but they aren't reflected in the final thing page yet.

On Sun, Jul 25, 2021 at 03:04 PM, Reginald Beardsley wrote:

Count cycles per tick and adjust the clock appropriately. That's not a difficult task.

Reg, can you send me the code for measuring the frequency so I can try to integrate it?
?
--

Thank you very much! I will print it after my current batch of 3D printer parts finishes, in a couple of days.

Chris Shaker

?

I will upload STP files to Thingiverse tomorrow when the license server for my CAD is back online.? I designed this in Creo, so I assume STP files will be most useful for for the majority of those interested.? I will also upload a STP assembly for both versions (foam and nofoam) with my reference CAD models for the tinySA, antenna, attenuators, and the SMA connector savers.

A good bit of hobby kit takes a reference e.g. VNWA and SDRplay RSP2.

But if the FW can take pps ticks via USB then it can discipline the local oscillator. No HW changes are needed. Just room for a bit of SW to control the frequency based on the pps tick. USB latency adds a modest amount of complication, but nothing hard. A 1 pps tick is about as low an overhead as I can imagine.

Problem at present is there is no room left in an STM32F072 part. Hence no room for other developers without disabling a unit by removing existing functions.

My point in posting is this:

There are a lot of ancillary functions as well as increased accuracy available if the clocks of multiple units are synchronized closely. This does not need to be a costly feature. Count cycles per tick and adjust the clock appropriately. That's not a difficult task.


Have Fun!
Reg

On Sun, Jul 25, 2021 at 11:10 PM, spiff72 wrote:

I have accounted for some

Hello spiff72,

Thank you very much for taking care about the SMA savers.

The total dimension with SMA savers is about 19 mm above the housing front.

73, Rudi DL5FA

I have accounted for some (or at least attempted to do so).? I don't have them, so can't verify myself, but the adjustments are included in the files I uploaded to Thingiverse in the link above.

That link didn't appear to be clickable, so here it is again:

On Sun, Jul 25, 2021 at 12:37 AM, spiff72 wrote:

OK - I am reasonably satisfied with this now.??

Hello spiff72,
I am sorry for beeing late, but the SMA savers on the tinySA would be also important for me.
73, Rudi DL5FA

Reg,
I think the 8560E has 1 Hz RBW available, but the 8560A does not.
--John Gord

I have uploaded to Thingiverse.? Here is a link.
https://www.thingiverse.com/thing:4916912

If anyone prints this - especially if you have the SMA Connctor savers, please let me know if it all fits!

On Sat, Jul 24, 2021 at 12:27 PM, Reginald Beardsley wrote:

I am assembling a portable RF bench setup with a nanaoVNA and 3 tinySAs among other things. I would very much like to be able to use a GPSDO (e.g. RFzero) to synchronize all of them.

With sufficient flash space, a one second tick sent over USB would probably be "good enough" in consideration of the other limitations.

Most higher end lab equipment uses an external 10 MHz. reference? input to sync the time base.? This requires additional circuitry in the test equipment for this function.? The NanoVNA and TinySA are low cost products that do not have this capability.

However they can achieve greater frequency accuracy if external frequency sources like a GPSDO are used to "calibrate" them. The TinySA has this feature in the current firmware and the NanoVNA-H and -H4 can be updated to a recent DiSlord version that has this feature.

Erik did a TinySA video on this subject >>?

Roger