A nut includes a bottom wall adapted to be connected fixedly to a printed circuit board, and an annular surrounding wall extending integrally from a periphery of the bottom wall away from the printed circuit board, having a threaded inner wall surface, and cooperating with the bottom wall to define a threaded blind hole for engagement with a bolt. In certain embodiments, the stringing machine includes a stand extending from a base at an angle between about 70 and about 89 degrees from horizontal. The second impedance includes a second transistor having a gate coupled to receive the control signal. If mounted on the top of a wall, the rail can be permanently or removably integrated with the cap structure, and mounted in a variety of manners, including with fasteners or clamps, such as in existing stake holes.