Definition
An electronic circuit that allows signals above a chosen cutoff frequency to pass through while blocking or attenuating signals below that frequency.
Plain English
A circuit that lets fast-changing electrical signals through and blocks slow-changing or steady ones.
Context Anchor
Seen in avionics, radio, audio, sensor, and flight-data discussions where unwanted slow signal changes or low-pitched noise must be reduced.
Derivation
Named for what it does: it 'passes' the 'high' frequencies. The opposite of a low-pass filter, which does the reverse.
Why Pilots Care
Reduces low-frequency noise that can mask ATC calls or navigation tones, directly affecting communication clarity and situational awareness.
Analogy
It is like a strainer that lets small, quick-moving parts through but holds back the larger, slower-moving parts.
Grounding Statement
A high-pass filter removes slow background changes and keeps quicker signal changes.
Intuition Check
High-pass does not mean the filter makes a signal higher or stronger. It means the filter lets higher-frequency changes through and reduces lower-frequency changes.
Example Sentence 1
The technician installed a high-pass filter to remove low-frequency engine noise from the intercom signal.
Example Sentence 2
During preflight checks the technician verified that the high-pass filter was set correctly for clear VOR audio.