Abstract: A method for potting and encapsulating electronic circuits by providing a homogeneous mixture of uncured thermosetting resin and curing agent in a flowable powder form with a particle size in the range of approximately 60 mesh to 200 mesh and curable in a range of approximately 125.degree. F. to 212.degree. F., and hollow microspheres having a diameter in the range of approximately 5 microns to 300 microns, intermixing the resin-curing agent and microspheres in a ratio in the range of approximately 35 percent to 45 percent resin-curing agent to microspheres by weight, enclosing the electronic circuit with a form, pouring the homogeneous mixture in the form to surround one electronic circuit, and heating the mixture to the required temperature for curing.

Abstract: A tubular body with an inner conductor coaxially mounted therein, one end being adapted for connection to a circuit or the like and the opposite end of the inner conductor being bifurcated for receiving an end of an external conductor in fixed engagement therewith in a first mode and for receiving a mating test connector in frictional sliding engagement therewith in a second mode. The tubular body defining an opening for receiving the external conductor therethrough and the end thereof being sealable to provide an electromagnetic shield around the connection of the center conductor and the external conductor.

Abstract: A homogeneous mixture of uncured thermosetting resin and curing agent in a flowable powder form with a particle size in the range of approximately 60 mesh to 200 mesh and curable in a range of approximately 125.degree. F. to 212.degree. F., and hollow microspheres having a diameter in the range of approximately 5 microns to 300 microns, with the resin-curing agent and microspheres being intermixed in a ratio in the range of approximately 35 percent to 45 percent resin-curing agent to microspheres by weight.

Abstract: A board of dielectric material having printed electrical circuitry on at least one side thereof with at least one mounting pad and a hole through the board in the center of the mounting pad for receiving the connecting lead of a component with a stress relief hole, having a diameter larger than the diameter of the mounting pad, extending from the surface opposite the electrical circuitry, coaxial with the mounting hole and to within a short distance of the surface carrying the mounting pad to permit minute motions of the circuit and component connected thereto and provide the necessary stress relief for thermal expansion differentials of connecting lead and board materials.