You're looking for, drumroll... a bias tee.
Basically, little more than an inductor from DC to line, and a series cap to block DC going out to the receiver. Evidently you'd want somewhat more than 75R / (2 pi 47MHz) = 0.25uH, and the capacitor can be way bigger than needed, ceramic chip caps are no problem here.
High frequency response depends on quality of both components. The capacitor can be laid out in a microstrip transmission line of the same dimension, that'll automatically be good to many GHz.
The inductor may have impedance dips due to internal resonances, particularly if it's a complicated winding (as you'd have for an oversized value), so there is some wisdom in using only what you need, not going gonzo. Shop for one with impedance curves and verify it's free of dips in the range. (The first (parallel) resonance is fine, by the way. Peaks are good. What matters is impedance dips.)
Also it needs to be rated for whatever current draw the line amp needs, including saturation current if it's a cored inductor.
Tim