Abstract: The present invention related to a method and a device for reducing the number of water vapour molecules per unit volume in a housing (1) by providing an end (11) of the housing (1) which has a lower thermal inertia than the rest of the housing with perforations (15). When the temperature outside the housing (1) falls some of the more energetic water vapour molecules in the housing (1) will leave the housing (1) via the perforations (15) and a small number of the less energetic molecules will enter the housing from the surroundings. This will lead to a nett flow of water vapour molecules out of the housing (1).

Abstract: In a quarter-wave coaxial cavity resonator, having a cavity with a cylinder inner wall (1), and bottom (3) and top (4) walls and a symmetry axis (2) with a resonator bar (5), a high coupling degree to a feed line (12) is obtained by a T-formed antenna with two equally long arms forming the antenna proper and the stem (9) forming the lead to the feed line. The antenna proper has one end (10) electrically and mechanically connected to the bottom end (6) of the resonator rod, whereas the opposite end (11) is free, and the antenna is parallel to the resonator rod and at a small distance therefrom.