For reference only.
9a.1 Output voltage level (on Ch0, or S11) at 50 Ohms load.
Further on the page are only oscillograms of signal levels at different frequencies (all 100mV/dev).
100kHz (DC1M):
1MHz (DC1M):
10MHz (DC1M):
100MHz (DC1M):
100MHz (DC50Ohms)
1GHz (DC50Ohms)
Additionally, for a note: