Optimum working frequency

Optimum working frequency (FOT). The highest frequency which is returned by ionospheric radio propagation to the surface of the earth for a particular path and time of day for 90 percent of the days of the reference month.
(FOT). The highest frequency which is returned by ionospheric radio propagation to the surface of the earth for a particular path and time of day for 90 percent of the days of the reference month.

Source

47 CFR § 73.701

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Scoping language

The following definitions apply to terminology employed in this subpart:

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