RST System
RST stands for Readability(5)-Signal Strength(9)-Tone(9) where tone is not usually used on phone.
Signal reports on phone are two-digit numbers using the RS portion of the RST system (no tone report is required). The maximum signal report would be “59”; that is, readability 5, strength 9.
On FM repeaters, RS reports are not appropriate.
-
Readability (1-5)
1 – Unreadable
2 – Barely Readable – occasional words distinguishable
3 – Readability with considerable difficulty
4 – Readable with practically no diificulty
5 – Perfectly readable
Signal Strength (1-9)
1 – Faint signals
2 – Very weak signales
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 (1-9)
1 – Sixty-cycle ac or less, very rough and broad
2 – Very rough ac, very harsh and broad
3 – Rough ac tone rectified but not filtered
4 – Rough note, some trace of filtering
5 – Filtered rectified ac but strongly ripple modulated
6 – Filtered tone, definite trace of ripple modulation
7 – Near pure tone, trace of ripple modulation
8 – Near perfect tone, slight trace of ripple modulatin
9 – Perfect tone, no trace of ripple modulation of any kind