BasicB-003-004-003
In a basic CW transmitter, why is the oscillator followed by a driver/buffer stage?
D
Answer
Basic radio theory
Type
A
To filter out noise from the oscillator
B
To shape the oscillator waveform to prevent key clicks
C
To filter out spurious emissions from the oscillator
D
To prevent load changes from shifting the oscillator's frequency
Answer Notes
An oscillator creates the base radio frequency signal, but its frequency stability can be easily disrupted by variations in the load connected to it. If an antenna or power amplifier were connected directly to the oscillator, changes during keying or antenna movement would pull the frequency off target, a problem known as "chirp".
To prevent this, a driver or buffer amplifier is placed immediately after the oscillator. This stage isolates the oscillator from downstream load changes while simultaneously boosting the signal strength enough to drive the final power amplifier.
Distractors like filtering out noise, shaping waveforms, or filtering spurious emissions are incorrect because those functions are handled by low-pass filters or key-click filters, not the buffer stage.
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In a basic CW transmitter, what type of electricity directly powers each stage?
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