The full form of BFO is Beat Frequency Oscillator.
A Beat Frequency Oscillator (BFO) is a dedicated oscillator used primarily in radio receivers. Its purpose is to create an audio frequency signal from radiotelegraphy (CW) transmissions using Morse code, making them audible. Without a BFO, these transmissions would sound like unmodulated carriers, or just silence, to the listener.
Here's a more detailed explanation:
- Function: The BFO generates a signal that is mixed (heterodyned) with the incoming radio signal.
- Heterodyning: This mixing process produces sum and difference frequencies. One of these difference frequencies falls within the audible range (typically around 1 kHz).
- Audible Tone: This audible frequency, known as the beat frequency, allows the operator to hear the Morse code signals.
- Types of Radios: BFOs are commonly found in communications receivers used for amateur radio, shortwave listening, and other radio communication services that use CW.
In essence, the BFO converts the inaudible radio frequency of Morse code signals into an audible tone that can be understood by the operator.
