How to measure high frequency with an oscilloscope without loading circuit down too much?
For RF measurements, it is best to scale the output down to 50 Ohms so that probe capacitance has less impact. 3 pF probe


100pF &lt; 10 Ohms at 180 MHz


even so a 3pF probe is still ~ 230 ohms reactance @ 160 MHz so low capacitance (1pF) diff. active FET probes are the best bet from TEK which are common industry tools who use these signals often.

~40 dB pad for up to 200MHz  plus load effect of 5k/(5k+500)