R = READABILITY 1 --
Unreadable 2 -- Barely readable, occasional words distinguishable 3 --
Readable with considerable difficulty 4 -- Readable with practically no
difficulty 5 -- Perfectly readable
S = 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
T = TONE � (FOR CW ONLY) 1 -- Sixty
cycle a.c. or less, very rough and broad 2 -- Very rough a.c. , very harsh
and broad 3 -- Rough a.c. tone, rectified but not filtered 4 -- Rough
note, some trace of filtering 5 -- Filtered rectified a.c. 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 modulation 9 -- Perfect tone, no trace of ripple or modulation of
any kind
