Hi All

For those still considered to purchase a TinySA I have made a very rude report which gives an idea how it is to use the TinySA? and see the complexity of this fantastic product

My apology for not organizing it better as I just did this report for a friend who asked some questions how clean the signal generation was and what noise floor it had. So It is compared to my HP signal generator which is supposed be one of the better onces. So I did measure the phase noise of that signal generator which sets the level for what TinySA is able to measure, and also two amplifiers OIP3 and there was a considerable difference.

Have fun

Kind regards

Kurt ?

Hi Erik

I also wondered about this low value. The -27dBm – 3dB is far to low a level but I could not produce a higher level of time of writing. ?That is simply that my R&S CRTU port 3 which produces such high level was destroyed during the TinySA testing because my HP power meter as the only one did not by my mistake had an AC plug with ground, and when I wanted to measure the output level on port 3 the N center conductor was getting contact prior to ground and “puf” port 3 killed. The old HP instruments has AC filters with large filter capacitances and are bloody dangerous. Shit happens.

I will take my Stabilock and use that and update the document and also try out using the TinySA.exe

Kind regards

Kurt ???

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On Mon, Jul 27, 2020 at 02:15 PM, Kurt Poulsen wrote:

, and also two amplifiers OIP3 and there was a considerable difference.

Kurt

In your document you state: "The combined signal tested with the R&S CRTU-RU And the IOP3 lower than -75dB relative carrier levels so it seem like the TinySA has an build in IOP3 of 4.7dB which is correctly calculated as rule of thumb is Pout + delta P/2 . That means The two testsignal with level -27dBm and combiner loss 3dB."

I guess IOP3 should be IIP3?
The value of +4.7dBm is surprisingly low. It should be above +15dBm.
See?
Can you check what happens when you increase the mixer drive?
CONFIG/EXPERT CONFIG/MIXER DRIVE
and try +10dBm and +13dBm.
This should increase the noise floor a bit but IIP3 may increase.

Hi Erik and all

I updated the report se delete the one I published yesterday.
I now get the same OIP3 figures as you. The levels must be much higher than the -30dBm I used to generate the better OIP3 figures .
However by using a 10dB internal Atten the figures raises 10dB now the TinySA is acting more linear.

The TinySA.exe also show good result on OIP3 but it is needed to toggle the RBW as repeating the measurement is chooses a very strange wide RBW so there is a bug

Kind regards

Kurt

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On Mon, Jul 27, 2020 at 11:22 PM, Erik Kaashoek wrote:

The value of +4.7dBm is surprisingly low. It should be above +15dBm.

Here are my measurements. Only settings changed from default where RBW set to manual 10kHz in second measurement both with attenuation set to manual and 0dB

First two signals at 0dBm with combiner loss of 3dB



Then the same signals set to -10dBm to check if the measurement is OK



The IP3 signals drop indeed 20dB when lowering the input with 10dB so what you see is internally generated.
Adding 10dB input attenuations drops them into the noise floor

I'm very curious why you measure a much different value