| Readability Code. | Meaning. |
|---|---|
| 1 | Unreadable. |
| 2 | Barely readable. |
| 3 | Readable with difficulty. |
| 4 | Readable with little difficulty. |
| 5 | Perfectly readable. |
| Signal Strength Code. | Meaning. |
| 1 | Barely detectable. |
| 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 | Very strong signals. |
| Tone Code. | Meaning. |
| 1 | Extremely rough note. |
| 2 | Very rough note. |
| 3 | Rough note. |
| 4 | Fairly rough note. |
| 5 | Note modulated with strong ripple. |
| 6 | Modulated note. |
| 7 | Near DC note but with smooth ripple. |
| 8 | Near DC note but with trace of ripple. |
| 9 | Pure DC note. |
The system known as RST reporting is normally used to give and receive useful and consistent signal reports between contacts.
As the name indicates, the RST reporting system is based around three numbers:
Readability
Signal strength
Tone (This being the 'note' of the Morse code transmission).
The meanings for the different numbers are given in the table on the right of the page.
A voice or telephony signal may be given a report of 5 and 7 if the signal is perfectly readable and is moderately strong.
A Morse signal that is totally readable, moderately strong, and has a pure dc note would be given a report 579.
Many receivers incorporate strength or "S" meters and these can be very helpful when trying to judge the strength of a station. The meters are calibrated in "S" units up to S9 and then beyond that they are sometimes calibrated in decibels over S9.
However one thing that you should remember is that Signal Meters fitted to radios are not always accurately calibrated and should only be used as a rough giide.