The RST System

Readability
1 - Unreadable.
2 - Barely readable, some words distinguishable.
3 - Readable with, considerable difficulty.
4 - Readable with, practically no difficulty.
5 - Fully readable.

Signal Strength
1 - Faint signals, barely perceptible.
2 - Very weak signals.
3 - Weak signals.
4 - Fair signals.
5 - Fairly good signals.
6 - Good signals.
7 - Moderately strong signals.
8 - Strong signals.
9 - Extremely strong signals.

Tone
1 - Extremely rough hissing note.
2 - Very rough ac note.
3 - Rough low pitched ac note, slightly musical.
4 - Rough ac note, moderately musical.
5 - Musically modulated note.
6 - Modulated note, smooth ripple.
7 - Near dc note, smooth ripple.
8 - Good dc note, trace of ripple.
9 - Pure dc note.