Here is my measurements:
50 Ohm load, sweep 50k-900M:
Peak voltage: 182 mVpp
RMS voltage: 92 mVrms
So, the max power level about -7.7 dBm
1 MOhm 18pF load, sweep 50k-900M:
Peak voltage: 324 mVpp
RMS voltage: 165.3 mVrms
So, the max power level about -45 dBm (note, 1 Mohm load!)
According to these values, the output impedance of CH0 is about 39 Ohm.
Measured with 100 MHz bandwidth scope, so the real voltage may be a little higher.
