Question T7A05
From subelement T7 - T7A
What is the name of a circuit that generates a signal at a specific frequency?
Why is this correct?
An oscillator is specifically designed to generate a continuous signal at a predetermined frequency without requiring an input signal. Reactance and phase modulators modify existing signals rather than create them, while a low-pass filter only allows certain frequencies to pass through but doesn't generate any signal itself. Oscillators are fundamental circuits found in all transmitters and receivers.
Memory tip
Remember the function pattern: circuits ending in '-ator' typically generate or create something (oscillator generates signals, modulator creates modulation), while filters process existing signals. The word 'oscillator' itself suggests back-and-forth movement at a specific rate, which describes frequency generation perfectly.
Learn more
In amateur radio operation, oscillators serve as the frequency reference for your transceiver's synthesizer, determining your operating frequency. Modern transceivers use crystal oscillators for frequency stability, often with temperature compensation (TCXO) or oven control (OCXO) for precise frequency control. The oscillator's stability directly affects your transmission accuracy and ability to maintain proper frequency privileges within amateur bands.
Think about it
Why do you think frequency stability of the oscillator becomes more critical as you operate on higher amateur radio bands?