Not a day goes by the place we don’t get asked by contractors how our aggregates are applied to various pool surfaces. Analog television sign requirements are designed to be displayed on a cathode ray tube (CRT), and so the physics of these devices essentially controls the format of the video sign. The picture on a CRT is painted by a moving beam of electrons which hits a phosphor coating on the entrance of the tube. movie mania This electron beam is steered by a magnetic area generated by powerful electromagnets close to the source of the electron beam.