The ornamental design for a microphonetransmitter, as shown and described.
FIG. 1 is a front perspective view of a microphone transmitter, showing my design.
FIG. 2 is a rear perspective view thereof.
FIG. 3 is a front elevation view thereof.
FIG. 4 is a rear elevation view thereof.
FIG. 5 is a left side elevation view thereof.
FIG. 6 is a right side elevation view thereof.
FIG. 7 is a top plan view thereof.
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is an enlarged view of an area labeled 9 in FIG. 1.
The broken lines in the drawings depict portions of the microphone transmitter that form no part of the claimed design. The dot-dash broken lines encircling portions of the microphone transmitter in FIG. 1 and illustrated in an enlarged view in FIG. 9 form no part of the claimed design.