In a single sideband and CW receiver, what component is located between the filter and product detector?

In a single sideband (SSB) and continuous wave (CW) receiver, the component located between the filter and the product detector is a radio frequency amplifier.

The purpose of the radio frequency amplifier is to boost the strength of the incoming RF signal before it undergoes further processing. It plays a critical role in ensuring that the signal levels are adequate for the subsequent stages of the receiver, particularly the filter and the product detector. By amplifying the desired signal, it allows for better signal-to-noise ratio, which is crucial for clear reception and effective demodulation into audio or baseband signals.

In SSB and CW reception, it's essential to maintain appropriate signal levels to accurately detect the modulated information. Other components like the beat frequency oscillator, which is used for creating a reference signal for mixing, and the audio mixer, which combines audio signals after detection, do not fit into the specific position identified in the question, since they have distinct functions in the processing chain. The phase-locked loop is typically involved in frequency synthesis or demodulation in more complex systems, but it also is not found directly in the position specified. Thus, the radio frequency amplifier is the critical component functioning as required between the filter and product detector.