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This thesis presents a solution to the problem of receiving a signal in the shadow and fringe areas. Theoretical and experimental investigation of the field behind an obstacle in a line of sight transmission path for UHF / microwave signals has resulted in a new approach to the analysis of electromagnetic fields in the shadow of an obstacle. Analysis using this approach showed the field to consist of varying amplitude and phase distribution. Additional analysis predicted an increase in received signal could be achieved if correlation between the field and antenna structure could be obtained. This was accomplished with a new antenna design. The thesis presents experimental and photographic evidence to support the theory. A novel technique involving the matching of the antenna structure to the field distribution, resulted in an increase of received signal in the diffracted field of up to 4 dB.

International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, Nevada / This paper discusses one approach to determine a characteristic of West - Java's air and ground segment as a block-box to accomodate radio waves propagation, especially in L-band ranges, by evaluating both the topographical data and radio reception pattern as measured from ground based telemetry receiving-end system. All the measured signals are random and assumed to be stationair and ergodic. In order to characterize the channel for polarization diversity reception, some statistical analysis are applied to the signal strength measured of both - RHCP and LHCP components of 1531 MHz propagated waves as transmitted fr om NC212-200 PK-NZJ-aircraft. Some computer calculated correlograms of measured data are shown herewith, it is focused for a certain radio corridor at radial 265E relative to the ground based receiving antenna. More over some curves of predicted multipath gain factor are also presented to gain more theoretical back ground. When this paper is written, a further field experiments on the matter concerned is beeing conducted.

Capturing Believers provides a history of the reception of American conservative evangelical missionary broadcasting from its inception in 1931 through the rise of the commercial era in 1970. The dissertation narrates accounts of two major Protestant stations, HCJB and ELWA, located in Ecuador and Liberia, respectively, as well as the U.S.-based project to build a custom transistor radio for the mission field. Employing a case-study approach, the thesis demonstrates the innovativeness of religious broadcasters who formulated a range of pragmatic responses to the drastic shortage of receiving sets in the southern hemisphere, including the use of social convention and the development of pretuned receiver technology. Missionary stations imported not only radios, but a constellation of American values into host countries through their reception activities. Overall, officials employed creative methods to construct a particular type of listener experience known as radio capture, characterized by regular listening in a domestic setting. By penetrating into the home or village and exposing listeners to proprietary broadcasts on a continual, even daily, basis, missionary receiver programs legitimized American conservative evangelicalism abroad and sowed seeds for a widespread revival of Protestantism in Latin America and Africa after 1970.