Definition
In a vacuum tube, the ratio of a change in plate voltage to the change in grid voltage that produces the same change in plate current. It is a measure of how effectively a small change in grid voltage controls the larger plate voltage in the tube.
Plain English
A number that tells you how much a tube multiplies a small input signal into a larger output signal. A higher number means the tube boosts the signal more.
Context Anchor
Seen in aircraft electrical, radio, and avionics discussions, especially when describing how weak electrical signals are strengthened inside equipment.
Derivation
From Latin amplificare, 'to enlarge or make greater.' The term names exactly what the tube does — it makes a small signal bigger — and the factor is the number that quantifies how much bigger.
Why Pilots Care
Pilots usually do not calculate amplification factor in flight, but the idea helps explain why radios, antennas, and electronic instruments can take a weak signal and make it usable.
Analogy
Think of a power steering system: a small turn of the wheel by your hands produces a much larger turning force at the tires. The amplification factor is the number that describes how much the small input is multiplied into the larger output.
Intuition Check
Do not read “factor” here as a cause or reason. In this term, it means a ratio: output compared with input.
Example Sentence 1
A vacuum tube with a high amplification factor can produce a strong output signal from a very weak input.
Example Sentence 2
Maintenance checks confirmed that the amplification factor remained within limits after the receiver was repaired.