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Have I just been unlucky and got a bad unit, or does everyone suffer spurious signals on their TinySA?

I see specific signals at 144.20MHz, 192.15MHz, and 240.19MHz.

They are unstable, and wander over a few hundred kHz, during a period of about an hour. Each are 12-15dB above noise floor in 10kHz RBW.

They are definitely internally generated. I have applied 50Ohm loads to the SMA connectors, and even operated the device inside a Faraday cage, but still the spurious signals remain visible.

Any feedback welcome.

John

Yes, to be done

Very good.

Could the firmware not have used the unique CPU serial number to create the device ID ?

On Sun, Aug 16, 2020 at 08:33 AM, ajparent1/kb1gmx wrote:

I've already used mine for tracking power line noise t 300mhz using a
small yagi for that band.

With an untuned amplified .3M untuned HF loop I"ve tracked all sorts
of items emitting significant noise.

You can measure the field strength of a source in dBuV/m if you change display units to dBuV and use a transducer calibrated in dB/m.? At a single frequency you can enter the tranducer factor (plus pre-amplifier gain if used) in Level->External Amp for a direct reading of field strength (only accurate at 1mtr distance from the source).

Similar technique using a current probe can be made for dBuA measurements.

- Herb

The tinySA uses the same VID/PID as the NanoVNA so if you are writing a script or program to communicate with the tinySA, and both a NanoVNA and tinySA are connected to your computer at the same time, you need to perform extra steps to automatically identify which port the tinySA is connected to.

1. The most reliable way is to query a connected port using the 'info' console command.

? ? >info

?

tinySA v0.3

2019-2020 Copyright @Erik Kaashoek

2016-2020 Copyright @edy555

SW licensed under GPL. See: https://github.com/erikkaashoek/tinySA

Version: tinySA_v1.0-49-ga63df47

Build Time: Aug 4 2020 - 17:52:05

Kernel: 4.0.0

Compiler: GCC 7.2.1 20170904 (release) [ARM/embedded-7-branch revision 255204]

Architecture: ARMv6-M Core Variant: Cortex-M0

Port Info: Preemption through NMI

Platform: STM32F072xB Entry Level Medium Density devices

If? 'tinySA' is contained in the response you have found the serial port the tinySA is connected to.

2. If you happen to have two tinySA's connected to the same computer, perhaps for automated frequency response measurements, then I've found the best way to? uniquely identify each tinySA is by using the 'deviceid' command.? Each tinySA is serialized at the factory with an 8-digit serial number.? The serial number is not written in the tinySA firmware, but Erik has included a 'deviceid ' console command that allows the user to set and query a deviceid.? If no deviceid has been set, or after a 'clearconfig 1234' console command, then querying the deviceid returns the following:

?> deviceid
? returns 0000

I always set my deviceid to my factory serial number (20070007):

?> deviceid 2007007
?> saveconfig 1234
?> deviceid
? returns 20007007

Always perform a 'saveconfig 1234' after setting a deviceid so that the id will be retained in flash memory.? Now your program or script can uniquely identify which tinySA is connected to a port by querying its deviceid number.? This works well, but only if the user has assigned a unique deviceid to each tinySA.

- Herb

I've already used mine for tracking power line noise t 300mhz using a
small yagi for that band.

With an untuned amplified .3M untuned HF loop I"ve tracked all sorts
of items emitting significant noise.

Very handy.

Allison
-----------------------------------------
Please post here, direct emails go to a dead letter box.

On Sat, Aug 15, 2020 at 11:09 PM, Erik Kaashoek wrote:

On Sat, Aug 15, 2020 at 03:30 PM, OneOfEleven wrote:

, I already started writing PC software for it.

Make sure you use the "scanraw" command i.s.o scan or sweep as scanraw can do unlimited points and sends data in binary, much faster

? ?Besides the faster speed and unlimited points, the tinySA 'scanraw ' command transfers corrected data - unlike the similar command on the NanoVNA which transfers raw data and requires you to externally apply calibration factors.? That's the major reason I've never used the 'scanraw' command on the NanoVNA.

? The binary format of the data returned by the tinySA 'scanraw' command is easy for C programmers to convert to actual dBm values.? Programmers using higher level languages like Python, will struggle doing the conversion until some examples start appearing on the web.

? From notes provided to me from Erik:

? ? ?Scanraw command outputs: ? ? ? ? ?byte end: '}

? ? ? ? ?level in dBm? = ((byte3 + (byte4) * 256) )? / 32 - 128

? - Herb

Don't forget to check PC supplies, The worst I found was a PICO supply.?

A very useful use of the TinySA is to track down sources of interference.

The horrors of today's unfiltered unscreened (and often unsafe - we had one leave burn marks all up our lounge wall after it exploded) chinese switched mode regulators/supplies, they have literally destroyed today's HF (and now slowly moving up into VHF/UHF) communications for many people around the globe :(

This is just one example - a baofeng walkie-talkie charger.

On Sat, Aug 15, 2020 at 03:30 PM, OneOfEleven wrote:

, I already started writing PC software for it.

Make sure you use the "scanraw" command i.s.o scan or sweep as scanraw can do unlimited points and sends data in binary, much faster

On Sat, Aug 15, 2020 at 07:06 PM, hwalker wrote:

Is that the only change in FW release v1.0-52?

I think so.

On Sat, Aug 15, 2020 at 05:46 AM, Erik Kaashoek wrote:

On Sat, Aug 15, 2020 at 05:41 AM, Erik Kaashoek wrote:

Integrated including using the calculated frequency i.s.o. the frequency array when printing
Will be in next FW release

FW released, version v1.0-52

Erik,
? Is that the only change in FW release v1.0-52?

- Herb

On Sat, Aug 15, 2020 at 04:50 PM, gary wrote:

I intend on using it for general lab work like identifying and quantifying spurious and harmonic emissions.

Great Gary,
? Erik should be a big help if you have questions about either measurement.? You will want to look over the Wiki to learn how to identify spurious emissions within the tinySA itself and how to mitigate them.? Its more of a issue on the HIGH INPUT range because it doesn't have the filtering and attenuation that the LOW INPUT does.

? I recommend that you use an external high pass filter and variable attenuator on the HIGH INPUT if you plan doing a lot of measurements in that range.

- Herb

I intend on using it for general lab work like identifying and quantifying spurious and harmonic emissions.
Gary W9TD

lol, I already started writing PC software for it. Which would also compile for all 3 main OS's - windows, nixies and macs.

I've done a lot of SDR 2D/3D real time panadapter/waterfall spectrum graph coding with intensity grading/fading etc over the years so can use that to do some real posh GL graph displaying you've yet to see ;)? anyone remember the QS1R ? ;)

On Sat, Aug 15, 2020 at 02:35 PM, OneOfEleven wrote:

A scan of the PCB with the covers removed.

OneOfEleven,
? You probably noticed the following:
? 1. The VDD and BOOT pins are available as a last resort for a user that can't access DFU mode in the usual way.
? 2. No SanDisk pads are available, so DiSlords's SanDisk modification for the NanoVNA would require a steady hand and nerves of steel to implement.
? 3. Pads for applying additional shielding are present.? Erik did a ton of experimentation so I'm pretty certain leaving out the shields was not cost savings move.? Still, the pads are there if a user is in an RF rich environment and thinks adding additional shielding will help.
? 4. Lots of space to add a larger capacity battery if longer operating life is needed.
? 5. The sma connectors are soldered securely to the pcb so less chance of shearing off from over torqueing cable connections.
? 6. The display cable does not appear to be connectorized so changing out the display will require above average soldering skills.
? 7. A UART interface is provided for possible RasPi and wireless experimentation.
? 8. A linear regulator is used for less power supply noise.

? Unseen is that the tinySA uses serial console commands so developers familiar with the NanoVNA should face few problems porting tinySA specific versions of their programs (hint, hint).

- Herb

Thank you Herb.

Am trying it with manual ref-level (-10dB) set, all appears OK now.

The auto ref-level code might need some tweaking by the looks of it :)

My heads full of NanoVNA code at the moment so still not got around to looking through the TinySA code. Played with it a lot though :)

On Sat, Aug 15, 2020 at 02:21 PM, OneOfEleven wrote:

The sudden jumps are always 10dB up/down.

OneOfEleven,
? Try setting LEVEL->REF LEVEL_>MANUAL.? Your video shows the reference level changing when the level shifting occur.? In rapidly changing signal environment,? manually setting the reference level and attenuation level will eliminate the bothersome level shifting.

? Nice idea to include the video. "A picture is worth a thousand words".

- Herb

A scan of the PCB with the covers removed.

The sudden jumps are always 10dB up/down.