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If the cable is terminated with the same impedance (50 or 75) The cable input appears as Zo = sqrt(L/C) as it gets no reflection.

Thus if the cables is lossless, the load sees the same signal attenuated at source by the voltage ratio of impedances.

  Ar = 50/(10k+50) over the bandwidth of the cable which I assume is far greater than your 30MHz. 

Coax being around 100 pF/m compared to a ~3.5 pF 10:1 scope probe but some attenuation will occur so measure the low R source or load only.

Normally 10~90% step response, Tr yields BW=0.35/Tr  but for Tau=RC using 0~63% risetime, it's a bit more BW.

Compute 0.5/RC=BW= 0.5/(1e4*3e.5-12)=1.4 MHz for 1 m or 14 MHz for 10m so be mindful of how you probe high impedance sources with RF.  It needs a FET probe or don't try.

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a thousand less words

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