We claim the ornamental design for a repeater for communication apparatus, as shown and described.
FIG. 1 is a front perspective view of a repeater for communication apparatus showing our new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left-side elevational view thereof;
FIG. 5 is a right-side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines are directed to environment and form no part of the claimed design. In addition, the unshaded surfaces throughout the views that directly adjoin the claimed solid line edges shown in the views form no part of the claimed design.