Modification of General Aviation Transponder to Incorporate a Crystal Video Receiver. Phase 1: Infinite Skirt Selectivity; Phase 2: Gat MK I; Phase 3: Gat MK II

摘要

The project was divided into three phases as follows: (1) Infinite skirt selectivity crystal video-receiving system, Equipment was developed for an infinite skirt selectivity crystal video receiving system. A pulse comparator was designed to gate the signal and thus to achieve the infinite skirt selectivity. However, pulse distortion in the cavity of the pulse comparator made it impossible for the system to work over the required dynamic range. (2) GAT MK I, The contract was amended to permit further development of a crystal video receiver using the previously developed equipment in phase 1 and a three-sectioned cavity preselector. This modification was developed, installed, and tested. The unit was within specification at room temperature except for the side lobe suppression. The side lobe suppression was out of specification at both ends of the power input dynamic range. (3) GAT MK II, The contract was again amended to permit further research and development of a receiver. A crystal video receiver was developed for installation in another GF Wilcox GAT, this time using a GF nuvistor RF amplifier instead of the transistor RF amplifier used in GAT MK I. In addition, several components of the basic crystal video receiver was redesigned to improve performance or to reduce cost or weight. This modification was developed, installed, and tested. (Author)