v1.3-5x / Can't capture short RF data bursts about tinysa

[erikkaashoek]

I tried to replicate using a 1000 cycle burts at 30MHz every 1s and this works fine.
Please explain how to replicate

[rleto577]

Thank you for the update.

I upgraded the firmware to the latest version and I'm able to capture data bursts again.
However, the frequency and amplitude vary over time as shown in the attached photo. I tested the burst with SATSAGEN and Rational Waves software and the frequency and amplitude remain very simular. I don't know why the TinySA exhibits these changes ?

[erikkaashoek]

If these are short bursts the position where you detect the burts will depend both on the frequency being sweeped and the moment of the burst
You have a 87ms scan time and a burst of 8ms, so a burst will take 9% of the width of the sweep (hence the 40kHz of the yellow trace as the sweep is 500khz wide). The overall shape (green trace) is caused by the RWB being 100kHz (-3dB width) and the burst being send at 314.98MHz
The FScan sweeps very fast and causes to miss some power as the time to load the power detector is on the edge
Check if normal scanning remove the "holes"

[rleto577]

Thanks for the explanation. As shown in the attached saved screen image, the maxHold trace indicates over time that the frequency and amplitude vary significantly causing reading errors. Based on your explanation, this behavior appears to be normal. As you suggested, could kindly you include the configuration for a normal scanning and what do you mean by "holes" ?

Thank you I advance.

[erikkaashoek]

Why don't you use zero span mode?

[rleto577]

Thanks for the suggestion, however I'm interested in finding the mid frequency of a pulse. Considering that the center frequency is unknown, It defeats the purpose of the zero span function which is primarily used for signal demodulation, channel power measurements and measuring envelope of a pulse at a known frequency.