This document summarizes the key components and functions of radio receivers. It discusses the types of modulation used in radio including CW, AM, and FM. It then describes the main components of radio receivers including the antenna, tuner, mixer, oscillator, and demodulator. It explains how superheterodyne receivers provide the best selectivity, sensitivity and stability by shifting signals to an intermediate frequency for processing before detection and amplification.
16. Beat Frequency Oscillator
Mixes with IF to produce an audio tone
|fif – fbf |= Beat Frequency
fif + fbf remove using a filter
Used in SSB and CW (no carrier wave)
Change crystal to change sideband