Actually this is the first time for me to measure "phase noise" (my main field is passive component, and not oscillator field) but I found most of spectrum analyzer can measure and calculate dBc/Hz value by the embedded function.

Here I will simply show the result below. Each evaluation is done by 100 and 300Hz RBW with 10kHz offset value. The first ones are 10MHz output.

As you see, it is around -74.5 dBc/Hz. 

Next one is 20MHz case,

The value for 20MHz is around -70dBc/Hz.

The last ones are the case of 200MHz (maximum frequency of Si5356).

The floor is buried in the noise level and I may need change ATT value but tentatively it is around -65dBc/Hz.