Abstract: A length of somewhat resilient yet deformable conductor wire is wound into a tight coil on a generally frustoconical mandrel. The coil is stretched axially inside the bore of an elongated, generally frustoconical antenna blank or casing such that the convolutions of the coil consecutively engage the inner periphery of the casing and are held against further movement. Liquid adhesive injected into one end of the casing in upright position sets to secure the coil to the casing. The resulting conical spiral antenna requires no inner core and is particularly adapted to mobile use such as on a car or a boat.