Prescalers are typically used at very high frequency to extend the upper frequency range of frequency counters, phase locked loop ( PLL ) synthesizers, and other counting circuits.
2.
In 1939 the 30-inch reflector was replaced with a Ross photographic telescope and for more than ten years after that, 1939 through 1951 Baker used the observatory's photographic telescope to help count the stars in the Milky Way and determine their distribution as part of Harvard's Star Counting Circuit.
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