In a single sideband receiver, where is the audio frequency amplifier located?

The audio frequency amplifier in a single sideband (SSB) receiver is positioned after the filter but before the product detector. This arrangement allows the receiver to effectively isolate the desired sideband from unwanted signals.

In SSB communication, intelligence (audio frequency signals) is modulated onto a carrier wave. The product detector is responsible for demodulating these signals back into audio frequencies, but it requires that the unwanted sideband and any other out-of-band signals be filtered out first. By placing the audio frequency amplifier after the filter but before the product detector, the system ensures that only the selected frequency components, which contain the desired audio information, are amplified. This setup is crucial for optimizing signal clarity and reducing interference.

Positioning the amplifier before the product detector would be ineffective since it would amplify all frequencies equally, including noise and unwanted signals, making it difficult to extract the intended audio. Similarly, placing it after the product detector would mean it would be acting on signals that are already fragmented, leading to further potential interference and noise. Therefore, the correct configuration of having the audio frequency amplifier positioned between the filter and the product detector is vital for the optimal operation of an SSB receiver.