| 摘要 |
Facsimile weather radar information (800 lines/frame) is stored, every third line, in a solid state RAM 35, capacity 256 three bit words per line, 256 lines. Subdivision of digital information from A/D converter 30 into digital words is accomplished using division by seven of television horizontal sync. The RAM is read at TV line rate (15.75 KHz) and lines of digital information clocked out of RAM at 1.59 MHz under control of a 14.3 MHz master oscillator which can be locked to external TV sync. Digital RAM output is processed into an analog signal, then through colorizer and blanking circuits (42 and 45) which insert synchronizing and color burst information, producing a broadcast compatible composite television output, presentable on color TV receivers with blue background and clouds, precipitation, etc., varying intensities of yellow. Input may be alternated between separate AM and FM detectors (15 and 19) from either mode of input transmission, and lower frequency horizontal and vertical sync is separated from the input. Black level adjustment of input signal is provided. Circular sweep at a nominal slow speed is mixed into the output signal.
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