OMEGA Norway Antenna System Characteristics: Modification and Validation Tests. Volume 1. Report Proper.
MEGATEK CORP SAN DIEGO CA
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Electronic measurements were performed on the Bratland Omega Antenna System. The antenna height had been significantly lowered in 1975, therefore tests were conducted on antenna performance in three configurations, so that a curve of performance for each frequency of operation is now available as a function of antenna span height. A determination of geometry by means of an optical survey. Reference data for future comparison, in the event the antenna spans are raised, are thus available. The electrical height of the antenna is 205 metres for 10.2 kHz when the span is in the so-called 1975 or intermediate elevation in which spans 1 and 3 are respectively paid out 14 and 10 12 turns from the high or 1973 position. The effective height varies directly as the mean span height, so that the percent increases are the same for electrical and geometrical height. For the 1973 position the effective height is 229 metres. There is a small frequency variation which is very nearly proportional to the fifth root of the frequency ratio. The antenna system efficiency in the 1975 configuration is 5.9 and in the 1973 configuration is 7.3 therefore with 150 kW antenna system input power the station will be able to radiate 10 kW when the spans are raised. For this mode of operation the spans are operating at about 70 of their design voltage limit or less full 10 kW radiated can be obtained by raising the spans back to the full 1973 height.
- Electrical and Electronic Equipment
- Radiofrequency Wave Propagation
- Navigation and Guidance