medium frequency(redirected from medium frequencies)
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medium frequency[′mē·dē·əm ′frē·kwən·sē]
A Federal Communications Commission designation for the band from 300 to 3000 kilohertz in the radio spectrum. Abbreviated mf.
The portion of the band of frequencies of electromagnetic radiation that lies between 300 kHz and 3 MHz. These, along with low frequencies, are used mainly for nondirectional beacons (NDB). The aeronautical allocation for NDBs covers a part of both bands from 200 kHz to 420 kHz.