Abstract: A cylindric grid electrode for electronic tubes formed by a set of carbon threads or filaments which have been coated with pyrolytic graphite. The coated carbon threads or filaments can be arranged in various configurations within the superfices of the cylinder such as in circumferentially spaced relation parallel to the cylindric axis alone, or in combination with another set of the coated threads or filaments located in spaced relation perpendicular to the axis or obliquely thereto and which overlay the first set and are soldered to the latter at the points of intersection. The coated carbon threads or filaments may also be arranged in two sets of helices oblique to the cylindric axis and which criss-cross and are soldered together at their points of intersection.