A word of warning for those that want to measure the spectral purity of their transmitter.
As the tinySA is specced to accept +10dBm without attenuation and +30dBm for some seconds with maximum attenuation you may be tempted to connect the output of the transmitter to the tinySA, set the tinySA to max hold and transmit for a short time, long enough for one sweep.
Even when your transmitter stays below +30dBm you risk making a wrong measurement, or even worse, if you have attenuation on automatic, destroy the tinySA as the tinySA will only adjust (e.g. increase) the attenuation for the next sweep.
The spur free dynamic range of the tinySA is a bit above 70dB with an RBW of 300kHz. This means that any signal that is more than 70dB above the noise floor will cause internally generated harmonics.
Let's take an example:
Without attenuation and with an RBW of 300kHz the noise floor is at -95dBm. With an input signal of 0dBm you are 25dB above the spur free dynamic range so there will be internally generated harmonics.
For a good measurement you should apply 25dB of attenuation?
Make sure to update the FW of you first batch tinySA as the newer FW contains an overload warning (the marker info turns red) to help you make a good measurement.
