Me too.
Not now

I understand there needs to be a frequency limit somewhere, but just wondering why 960mHz.? I would love to see it go to maybe 1.5gHz.
Keith

Erik,
? Another feature I hope you can add to a future wish list is a menu selectable reference line.? It would be a line drawn across the length of the display at a level chosen by the user that could be turned on or off.

? It's a feature I have used frequently on other spectrum analyzers for quick visual pass/fail indication (limit line).

- Herb

As the internal flash can endure above 10k write cycles I assume using the internal flash with a warning not to store too often is OK.

Saving settings to one of the internal memory slots now also saves the stored trace and loading a saved setting will restore the stored trace.

This provides 4 memory slots to save traces?

If storage is a very important function, consider adding a WSON8-packaged SPI FLASH to the current PCB. some SPI connections need to be modified, and consider whether the current MCU has enough resources to drive the SPI FLASH.?A 1Gb (128MB) SPI NAND Flash costs about $1. Attached is the datasheet.

Hi Erik,

? ? ? ? ? ? Digital scope functionality sounds good and thanks for your trace storage addition to the list!

Tom, VA7TA

For testing the procedure I'e used is:

Both signals are low pass though a 7 or 9 section filter.? They must be
clean and the usual source had? HP part numbers.

Each signal has its own step attenuator.

I then combine them with a resistive mixer or other RLB (makes a good combinter).

Then with know quality gear measure levels.? its more to calibrate what
I'm putting in vs what I think I'm putting in.? Then verify the SFDR of
the test setup.? Its very easy at high level for one source to push
another source into distorted or mixed output.? Isolation and filters
are helpful in keeping that from being an issue.

With that SFDR, Compression and IP3 are determined.

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

An important parameter of a spectrum analyzer is the spur free dynamic range (SFDR).
This is the range in dB between the noise floor and the strongest signals that can be used without generating visible mixing products inside the spectrum analyzer.
If the IIP3 is known you can calculate the SFDR
As I have looked previously?at IIP3 I thought it would be interesting to see a practical example what staying within the SFDR implies.

As a test I'm using two somewhat clean input signals, one of 15MHz



and one of 9MHz (not so clean, see the small spur at 30.5MHz)



If you add these signal in a way they do not interact and feed them to the input of the spectrum analyzer you should only see the pure sum of the two spectra above.?

So first the combined spectrum with 0dB attenuation.




There are two signals that should not exist. The first at 24MHz (the sum of 9MHz and 15MHz) at -80dB and a second at 39MHz (2 times 15MHz + 9MHz) at -86dB . One would expect something at 33MHz (15MHz + two times 9MHz) but this one is not visible.?
In order to investigate if these mixing products are generated in the spectrum analyzer or in the generators (due to lack of isolation) I did two extra measurement.

First with 5dB increase in attenuation in the spectrum analyzer?



The signals that should not change did not change (within the +/1dB measurement accuracy) . The 24MHz mixing product went down with about 1dB and the 39MHz mixing product disappeared.
This seems to suggest the generator delivering the 9MHz signal is contributing to the mixing because with a 5dB increase in attenuation the mixing products both should have disappeared.
But the positive conclusion is that the tinySA will give you a SFDR of at least 70dB at a RBW of 30kHz.

Increasing the attenuation to 10dB gave this picture.



?The signal at 24MHz went down with another 1dB so this again suggests I may have to find a better way to mix the output of the two generators.

I welcome a critical review of my conclusions by the esteemed audience of the group.

On Wed, May 6, 2020 at 06:49 AM, <erik@...> wrote:

Normalize does a "Store" and enables "subtract stored" so it is most useful with a noise generator (or tracking generator)? ?

? ?I knew that 500 MHz noise generator I purchased a few years back would eventually be of use.

- Herb

On Wed, May 6, 2020 at 07:11 AM, <erik@...> wrote:

On Wed, May 6, 2020 at 06:30 AM, hwalker wrote:

?I think one of the next most requested features you may be receiving is amplitude offset menu to account for external attenuation or preamplification.

Implemented
Under LEVEL added EXTERNAL AMP, value in dB, can be negative. Added status display to warn

?Outstanding!

- Herb

On Wed, May 6, 2020 at 06:30 AM, hwalker wrote:

?I think one of the next most requested features you may be receiving is amplitude offset menu to account for external attenuation or preamplification.

Implemented
Under LEVEL added EXTERNAL AMP, value in dB, can be negative. Added status display to warn

Normalize does a "Store" and enables "subtract stored" so it is most useful with a noise generator (or tracking generator)
In the settings tab you can change the "Zero level" setting to offset any external attanuation or amplification.
On the tinySA itself you can use the "actual power" under "settings" to offset anything. But it would be fairly simple to add under LEVEL an option OFFSET

On Wed, May 6, 2020 at 02:40 AM, <erik@...> wrote:

Herb,
All units are implemented, both in marker info and graph display, hope I did the math correct.

=================================================================
Glad to hear Erik.?
? ?I think one of the next most requested features you may be receiving is amplitude offset menu to account for external attenuation or preamplification.? Does the "Normalize" menu option in the tinySA software application accomplish amplitude offset?? I played with it but couldn't correlate the changes.

? BTW, the config file also corrected the string value exceptions I was previously receiving.

- Herb

For good measurement try to keep strongest signal minus attenuation below -20dB if possible

Both

sorry to disturb as I have a question that's perhaps a little naive...
does the software display in real time what the SA is doing? or it just captures static images?

Claudio

开云体育

Herb,
All units are implemented, both in marker info and graph display, hope I did the math correct.

We're very sorry, we're not sure when we'll start mass production of the tinySA, we're sending the beta version of the tinySA to some of the users who participated in the inner test, but due to COVID-19, we're distributing it very slowly and it could take up to a month. We will make final improvements and finalize the version after we get feedback from users, thank you for your interest, I will publish it in this group as soon as we are ready for mass production.

erik, load the configuration file you provided and it work fine.