The ornamental design for a portable fieldradio, as shown and described.
FIG. 1 is a front perspective view of a portable field radio, showing our new design;
FIG. 2 is a rear perspective view of the portable field radio of FIG. 1;
FIG. 3 is a front view of the portable field radio of FIG. 1;
FIG. 4 is a rear view of the portable field radio of FIG. 1;
FIG. 5 is a right side view of the portable field radio of FIG. 1;
FIG. 6 is a left side view of the portable field radio of FIG. 1;
FIG. 7 is a top view of the portable field radio of FIG. 1; and,
FIG. 8 is a bottom view of the portable field radio of FIG. 1.
The dot-dash broken lines immediately adjacent to shaded areas define boundary lines that form no part of the claimed design. All other broken lines show portions of the portable field radio that form no part of the claimed design.