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Paper: |
Active Antenna Development for the Long Wavelength Array |
Volume: |
345, From Clark Lake to the Long Wavelength Array: Bill Erickson's Radio Science |
Page: |
433 |
Authors: |
Stewart, K.P.; Hicks, B.C.; Crane, P.C.; Ray, P.S.; Gross, C.; Polisensky, E.J.; Erickson, W.C. |
Abstract: |
We are developing and testing active baluns and electrically short dipoles for possible use as the primary wideband receiving elements in the Long Wavelength Array (LWA) for HF-VHF radio astronomy. Several dipoles of various designs and dimensions have been built and tested. Their useful range occurs when the dipole arms are approximately 1/8 to one wavelength long and the feedpoint is less than 1/2 wavelength above ground. An eight-element NRL LWA Test Array (NLTA) interferometer has been built and fringes have been observed from the brightest celestial sources in the frequency range from 10MHz to 50 MHz. The antenna temperatures vary from about 10% to 100% of the average brightness temperature of the galactic background. With these parameters it is easy to make the amplifier noise levels low enough that final system temperature is dominated by the galactic background. |
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