RST Signals Explained

RST, which stands for Readability, Signal Strength and Tone. On CW, all three codes are used for a report, extremely strong, and perfect tone. On phone only the first two codes are used. A report might be 55 meaning perfectly readable, fairly good signals. In operation the signal strength is often taken from a reading on the S-meter.

Readability

1--Unreadable.

2--Barely readable, occasional words distinguishable.

3--Readable with considerable difficulty.

4--Readable with practically no difficulty.

5--Perfectly 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--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.

Last updated April 4, 2005