If you know the impedance of your 1:1 probe coax is not 50 Ohms but a low capacitance type that Tek uses such as 75 ohms (or higher) then you would use a series R of 75 Ohms series input and same on DSO as a load with a 2:1 scale factor.

The DSO 50 Ohm internal terminator is convenient, but this will cause some ripple in the coax response from mismatch at 1/4 wave multiples >~ 100 MHz. So it may be better to use a BNC "T" on the DSO and insert a thruhole 75R like a jumper, bridging the BNC centre and barrel. (*)

For measuring DCDC ripple voltage , you can use the same 1:1 coax probe method or SMA Coax but use an additional series Cap to Vdd then series Rs and matched load Rs to DSO. This will give textbook quality waveforms of your ripple with > 100 MHz BW.

If you know the impedance of your 1:1 probe coax is not 50 Ohms but a low capacitance type that Tek uses such as 75 ohms (or higher) then you would use a series R of 75 Ohms series input and same on DSO as a load with a 2:1 scale factor.

The DSO 50 Ohm internal terminator is convenient, but this will cause some ripple in the coax response from mismatch at 1/4 wave multiples >~ 100 MHz. So it may be better to use a BNC "T" on the DSO and insert a thruhole 75R like a jumper, bridging the BNC centre and barrel. (*)

For measuring DCDC ripple voltage , you can use the same 1:1 coax probe method with < 1cm connections to gnd. You can also use 50 Ohm Coax with on-board SMA socket or similar. But you must use a series Cap to avoid risk of burning out the 50R load.

So Vdd > low ESR series 0.1uF//1uF > series 50=Rs << coax << DSO 50R shunt. This will give textbook quality waveforms of your ripple with 10kHz to > 100 MHz BW.

Additional info: https://download.tek.com/document/02_ABCs-of-Probes-Primer.pdf This is just the basics. It's more complicated than this.