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Just ordered one thanks for letting us know.

Ed -K7OCK?

On Tue, Oct 6, 2020 at 07:58 AM, OneOfEleven wrote:

or did you wind the cable around a toriod ring I wonder

3 turns on a toroid ring

Did you use a clip on choke around the USB cable or did you wind the cable around a toriod ring I wonder ?

Only telescopic antenna connected, you see the MCU clock harmonics



Inactive USB connected



Active USB connected




Adding a choke on the USB cable with active USB



inactive USB with chocke



Remember you can scan without USB connected and do DISPLAY/PAUSE SWEEP to pause the sweeping (or you can store in stored trace) when you have a good scan and connect the USB for screen grabbing.

Oh, you are using the telescopic antenna at the input and then you connect a USB cable.
The USB cable is acting as part of the antenna and is picking up a huge amount of noise.

The same thing happens when you have a signal generator and a tinySA and both are connected to the computer with USB and the cable between the generator and the tinySA is not the lowest resistance between the two devices (because of bad cable or bad contact)

I get exactly the same type/pattern of interference show up on the TinySA/PC software when I have the TinySA's own little aerial on the unit and the unit plugged into the PC with comms running - it picks up the USB noise from the USB lead it would seem (Erik pointed me to this being the problem when I first noticed it).

I think a good quality fully screened USB lead from TinySA to PC might help (not tried it yet). I do know that moving the antenna away from the TinySA and USB lead fixes the problem for me.

On Tue, Oct 6, 2020 at 02:34 AM, Erik Kaashoek wrote:

Changes:
- Added localization changes from OneOfEleven
- Updated 3 small errors reported by Herb
- Added External Amp setting

======================================================
Erik,
? Looks like you can take a breather for a while.? TinySA-App now feels like a native tinySA application rather than a port from Cathy's NanoVNA-App (wish I could say the same for VNA-QT for the V2).?

? Thanks to Cathy for developing the base application and you for delivering the tinySA specific version to your users.

? Two very minor issues to address in a future release:

? 1.? Marker display mode s11 reference.

? ? ??


? 2. As previously reported by another user, the "Save Image" automatically created file name has an s11 reference (tinysa_LOGMAG_S11_2020-10-06_08-18-09.png).? The "Save CSV" file name is fine (tinysa_2020-10-06_08-19-35.csv).


? All other tested software features continue to work as expected.? I used the "External Amp" setting this morning with an external attenuator and it also worked as expected.

? Best regards,

- Herb

On Tue, Oct 6, 2020 at 06:25 AM, Walt M. wrote:

I noticed the scan pattern changes when the USB cable is connected to a PC

Hi Walt,

It's a bit difficult to tell what's going on from your screen shots, and you don't mention what you are measuring at the time, but to me it looks to me like hash from your PC and USB port being conducted as common mode current onto the spectrum analyser input. It could be from the PC power supply or clock and data signals, but either way they tend to look like a comb of frequencies clustered around a few centre frequencies. The comb distribution will change depending upon cable length etc.

A choke may help, but it would have to be optimised for the frequencies in question.

The good news is you now have a suitable test instrument to track down noise sources like these. Buy a big bag of ferrites and go around your house, with a 6" bit of wire as an antenna on the TinySA.

As soon as you bring the antenna close to a noisy power supply you will defiantly see the baseline spectrum rise on the TinySA.

Regards,

Martin

Thanks Erik,

I will give this a try !

73 Manuel; DL2MAN

There is Comtekk Sinad. Not free, 39$ shareware.
And there is Arta. Which you can use in "demo" mode with some limitations? that does audio spectrum analysis and THD and THD+noise measurements

Hi Erik,

I?m using the TinySA not only as spectrum analyzer, it recently became pretty handy to have an RF Source with adjustable level for some receiver tests.
With external attenuators I could get it down to the lower limit of receivability.
This tiny little thing almost substitutes a complete "Communication Systems Analyzer" we used to have back in my days in the radio workshop.
But one thing is missing, and I think it would be possible to integrate that into Tiny-SA.exe

- Possibility to connect Audio out (of DUT) into Soundcard, so you can measure S/N Ratio while changing RF Input into receiver, so you have a SINAD measurement.

Can this be done ? Or is ther maybe already a tool, that can be used for those kind of RX Sensitivity measurements ?

73 Manuel; DL2MAN

Release tinySA-App 1.0.240.4
Changes:
- Added External Amp setting

Release tinySA-App 1.0.240.3
Changes:
- Added localization changes from OneOfEleven
- Updated 3 small errors reported by Herb

Hi Walt
Coul you tighten you SMA connectors? Hand tight is good enough

Hi all!
New user of the TinySA here. I am familiar with spectrum analyzers as I have been in electronics and ham radio most of my life. Saw this device and bought two. Very nice quality and operation for the price. I'll find many uses for these and the NanoVNA-H4 as well. Just got these a week or so ago and have been learning all I can about their functionality. I'm not new to SAs and Smith Charts as we covered these in my tech classes at ITT Tech. Just need to do some heavy review of the specs and formulas.
Now, to the point.
While using the TinySA, I noticed the scan pattern changes when the USB cable is connected to a PC, and changes even more when the program is activated. I have attached several pictures, some taken with a cell phone cam, two screen grabs (attached). The screen grabs are somewhat smaller than the screen photos.
Some info, I'm using the latest DFU: 1.1-5ge0ab998 and Software for Win10: NanoVNA 1.0.234 by OneOfEleven and Erik, as well as TinySA App (Win10) v1.0.236.2 by OOE and Erik. I also checked on older versions with the same results.
I have a rather high noise floor here but I am not sure why the trace changes from no USB connection and on battery, to USB connected and program running. This trace change happens on all of my saved settings. Yes, I did calibrate both of my SAs twice after resets and reprogramming, made no difference. Cables all test fine with the NanoVNA and continuity tests. Anyone else see this anomaly? Any thoughts as to why this is happening? Maybe put a ferrite choke on my USB cable?
Other than this one item, all of my devices seem to be doing what they are supposed to do. I can see when I key up a transmitter (on low power) at the right frequency(ies) using the antenna. I can generate the 1K tone on various frequencies and tune them in on my radios, AM and FM mod. And I can see other spikes and signals from some RF remote controls I have.
More experiments and tests and usages in the future!
I want to thank Hugen, Erik, DiSlord, OneOfEleven and others for some amazing products and software! Keep up the good work! Will be looking for more updates as they are published.
Thanks again!
Walt Morey, WA7SDY
Tacoma, WA

tinySa have only 8bit sampling on measure

Or is it due to limited bit resolution elsewhere in the tinysa's sampling ?

This capture is also showing the limited 16-bit scanraw dB resolution (clear vertical bit resolution). 24-bit would certainly solve that.