RST code

Sep 22, 2015

The RST system is used by amateur radio operators, shortwave listeners, and other radio hobbyists to exchange information about the quality of a radio signal being received. The code is a three digit number, with one digit each for conveying an assessment of the signal's readability, strength, and tone.[1] The code was developed in the 1934 by Amateur radio operator Arthur W. Braaten, W2BSR.
-From Wikipedia

RST Signal Reports
ValueReadabilityStrengthTone (CW only)
1UnreadableFaint signals, barely perceptibleSixty cycle a.c or less, very rough and broad
2Barely readable, occasional words distinguishableVery weakVery rough a.c., very harsh and broad
3Readable with considerable difficultyWeakRough a.c. tone, rectified but not filtered
4Readable with practically no difficultyFairRough note, some trace of filtering
5Perfectly readableFairly goodFiltered rectified a.c. but strongly ripple-modulated
6-GoodFiltered tone, definite trace of ripple modulation
7-Moderately strongNear pure tone, trace of ripple modulation
8-StrongNear perfect tone, slight trace of modulation
9-Extremely strongPerfect tone, no trace of ripple or modulation of any kind