Sealed transmitter assembly for subsurface utility installations

b, cb, cAn assembly for installation in a subsurface ground enclosure has an electronic transmitter, an antenna and other circuitry that are encapsulated against moisture conditions. The assembly comprises a circuit board supporting radio frequency transmitter circuitry, the circuit board having at least two orthogonal edges, an antenna having two 90-degree bent portions extending from orthogonal edges of the circuit board, a housing bottom portion with an internal barrier separating an L-shaped antenna compartment adjacent two sides of the circuit board from a battery compartment underneath the circuit board, sealing material for encapsulating the circuit board and the batteries in the battery compartment, and a cover that protects the antenna compartment from entry of the sealing material.