We claim the ornamental design for a heat, water, and shock resistant combination radio modem and amplifier, as shown and described.
FIG. 1 is an upper right front perspective view of a heat, water, and shock resistant combination radio modem and amplifier showing new design, features shown in broken line are for illustrative purposes only and form no part of the claimed design;
FIG. 2 is a front plan view thereof;
FIG. 3 is a right side elevational view thereof;
FIG. 4 is a rear plan view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The broken lines shown throughout the views that are immediately adjacent to the shaded areas, and define unshaded regions, represent the bounds of the claimed design, while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.