A method of assembling an external telemetry unit for a projectile comprising the steps of providing a shell whose inside is formed to match the contour of the projectile body, encircling the front of the shell with a flexible battery and flexible electronic circuitry, and covering the flexible battery and flexible electronic circuitry with a plurality of contoured antennas. Also disclosed is a method of using an external telemetry unit comprising the steps of removing the fuze from a projectile having a projectile body and a fuze, sliding the unit over the front of the projectile body; reinstalling the fuze, firing the projectile, and observing the projectile data transmitted by the unit.