The ornamental design for a wirelessdoorbelltransmitter, as shown and described.
FIG. 1 is a first perspective view of a wireless doorbell transmitter showing my design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines shown in the drawings depict portions of the wireless doorbell transmitter in which the design is embodied that form no part of the claimed design.