Overvoltage protection for radio receivers HF inputs

摘要

The protective elements of the overvoltage protection must not affect the technical parameters of the receiver etc., i.e. they must safe-guard the sensitivity of the HF characteristics The known protective elements are incorporated in a HF filter in such manner that their harmful reactive values form a part of this filter. Preferably at least two different overvoltage protectiVe elements are used, which safeguards both the protection and a rapid response of such elements. - The filter, comprising coils may be so designed that the coils between the reference potential and the signal path attain saturation magnetising at higher currents. In this manner the positive characteristics of the different protective elements, such as rare gas filled overvoltage arresters, suppressor diodes etc., are utilised and the negative ones compensated. (0/2) USAB- US4695283 A The endoprosthesis comprises an anchoring shaft having circular steps in supporting regions (X,Y) of the anchoring shaft in which a support of the anchoring shaft in the bone takes place. The shaft has at a free end remote from a mouth of the bone opening a straight portion. The steps are formed in the straight portion one after another without undercuts. - The shaft conically widens from the end towards an end opposite to the free end. The steps have contours which are in the region in which the steps are supported in the bone, individually adjusted to respective cross-sections of the bone hollow. The cross-sections exist at the positions of the individual steps when the endoprosthesis is inserted into the bone.