A versatile power-line-carrier system

Power-line carrier has kept pace with the swift progress of the electronic art during the last several years. This progress has been due mainly to the stimulus injected by the war effort. In most of the specialized fields of electronics, the advancement was necessitated and promoted strictly for military purposes. Power-line carrier, however, was and is the soldier of the home front. Its duties have been expanded to include as many functions as possible consistent with reliability, economy, and convenience. The economic feature is especially significant now, since, during wartime emergencies, the material resources of the nation are allotted, and properly so, to those agencies concerned with the battle front. Material for new power lines, new generating equipment, new telephone lines, and for other similar programs of expansion is therefore not generally available. However, power-line carrier comes to the rescue and effectively provides additional circuits and higher power-handling capacity for existing installations.