Question T6C10
From subelement T6 - T6C
What is component 3 in figure T-3?
Why is this correct?
Component 3 in figure T-3 is a variable inductor, which appears as a coil symbol with an arrow through it indicating variability. Variable inductors are adjustable coils used in antenna tuners to match impedance. The arrow distinguishes it from a fixed inductor. A connector would show plug symbols, a meter would show a circle with measurement markings, and a variable capacitor would show parallel plates with an arrow.
Memory tip
In schematic diagrams, variable components always include an arrow symbol through or near the basic component symbol. This pattern applies universally: variable resistors, capacitors, and inductors all use arrows to indicate adjustability. Remember that the base symbol (coil for inductor, parallel lines for capacitor) determines the component type.
Learn more
Variable inductors in antenna tuners provide impedance matching between transmitters and antennas across different frequency privileges. They work with variable capacitors to create resonant circuits that transform impedance. In practical operation, you adjust these components while monitoring SWR to achieve optimal power transfer and meet FCC emission standards for spurious radiation suppression.
Think about it
Why do you think antenna tuners need both variable inductors and variable capacitors to achieve proper impedance matching across different amateur frequencies?