IMPEDANCE MEASUREMENTS OF UNBALANCED ROCKET ANTENNAS NEAR THE EARTH'S SURFACE.
UTAH UNIV SALT LAKE CITY UPPER AIR RESEARCH LABS
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An investigation was conducted to explore the possibility of accurately determining the free space impedance of a single, unbalanced, whip antenna mounted on a rocket. A system was developed to measure the impedance without any external electrical connection to the rocket. A method of suspending the rocket model was developed so that an error of less than 2 ohms was introduced into the impedance of the electrically short antenna by surrounding objects including the earth. The effects of frequency and geometry of the rocket-antenna system on the minimum height at which the rocket can be supported above the ground for accurate measurements were investigated. It was found that for antennas between 2 and 6 meters, rocket diameters between 0.2 and 0.5 meters, and frequencies between 10 and 12 Mhz, that a support height of 2.5 meters for the rocket model was sufficient for accurate measurements. Author
- Electrical and Electronic Equipment