Sunday, August 5, 2012


The RST system is a way of reporting on the quality of a received signal by using a three digit number. The first digit indicates " Readability" ( R ), the second digit indicates received "Signal Strength"(S) and the third digit indicates "Tone" (T). A fourth character is used on rare occasions to indicate the presence of a defectively keyed CW signal. 

For example, a signal report of 589 indicates a completely understood strong CW signal with an excellent note. On the other hand, an RST of 387C would be a dificult-to-copy, chirpy transmission. Most signal reports have an "R" of 4 or 5 and "S" and "T" of 7 to 8.

1 - Unreadable
2 - Barely readable, occasional words distinguishable
3 - Readable with considerable difficulty
4 - Readable with practically no difficulty
5 - Perfectly readable

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 (T) Use on CW contacts only
1 - Extremely rough ac tone and very broad
2 - Very rough ac tone, very harsh and broad
3 - Rough ac tone, rectified but not filtered
4 - Rough note with some trace of filtering
5 - Filtered rectified ac but strong ripple modulation
6 - Filtered tone with definite trace of ripple modulation
7 - Near pure tone, trace of ripple modulation
8 - Near perfect tone, slight trace of modulation
9 - Pure DC note with no trace of ripple or modulation of any kind

CHARACTERISTIC ( Optional, CW only)
X - Very stable signal, the quality of crystal control ( usually understood and hardly ever used )
C - Chirpy keyed signal or frequency variation defect
K - Key click or noticeable make/break keying flaw

                                                             RST 559 CW QSOs

             CW QSO with Anton from Birmingham, England - 10901.9 km dari Kulaijaya, Johor.

1 comment:

F4GHW said...

I am studying CW since 2011! All your advices on the blog are very interesting... Read and look in repetable time... Thank you Zaki for all! Your Blog is QRO, Ham radio of 21 century! I hope to listen or Qsl you in next months on the frequencies. 73 & 44 from F4GHW Chris