Abstract: An electrical LC resonant circuit, particularly useful for channel filters in carrier frequency technology, has a fixed-tuned coil and a capacitor tunable by the removal of layer surface portions. The capacitor is constructed as an essentially flat, self-healing layer capacitor having a relatively small number of layer surfaces and dielectric layers lying one upon the other.

Abstract: An electrical capacitor in which metallized foils are loosely disposed one on top of the other and in which the dielectric layer is formed of materials which have desirable electrical properties but which are not particularly adapted to regeneration having a metallized surface which is insulated against the moisture by a liquid insulating oil. The insulating oil layer may consist of polyisobutylene or a silicone oil. A solvent is used to apply the oil and the solvent is given the opportunity to evaporate after the application.

Abstract: A layer or stack type capacitor having a covering foil, and adhesion-imparting layer disposed on the surface of the covering foil, a first electrically conductive layer disposed on the surface of the adhesion-imparting layer and a dielectric and second electrically conductive layer disposed respectively against the surface of the first electrode. The first conducting layer or electrode is made sufficiently thin so that the adhesion-imparting layer may adhere to the dielectric layer through pores of the first electrically conductive layer. The result is that the covering foil, adhesion-imparting layer, first electrically conductive layer and dielectric adhere together and are hermetically joined to eliminate the possibility of moisture entering into the vicinity of the first electrode to cause harmful corrosion.