RST signal report guide
How to give and interpret signal reports in amateur radio. The RST system explained with real-world examples.
How to give and interpret signal reports using the RST system.
The RST system
Signal reports in amateur radio use the RST system: Readability, Strength, and Tone (tone is CW only). On SSB, you give an RS report (readability and strength). On CW, you give an RST report (readability, strength, and tone).
Readability (R) — 1 to 5
How well can you understand the words or copy the code?
| R | Meaning | In practice |
|---|---|---|
| 1 | Unreadable | Cannot make out anything |
| 2 | Barely readable | Catch a word here and there |
| 3 | Readable with difficulty | Can copy with concentration and fills |
| 4 | Readable with little difficulty | Mostly solid copy, occasional miss |
| 5 | Perfectly readable | Every word/character is clear |
Strength (S) — 1 to 9
How strong is the signal? Corresponds loosely to the S-meter reading.
| S | Meaning | S-meter approx |
|---|---|---|
| 1 | Faint | S1 |
| 2 | Very weak | S2 |
| 3 | Weak | S3 |
| 4 | Fair | S4 |
| 5 | Fairly good | S5 |
| 6 | Good | S6 |
| 7 | Moderately strong | S7 |
| 8 | Strong | S8 |
| 9 | Extremely strong | S9 or above |
Tone (T) — 1 to 9 (CW only)
The quality of the CW tone. Modern transmitters all produce a T9 (pure) tone, so this number is almost always 9.
| T | Meaning |
|---|---|
| 1 | Extremely rough, harsh |
| 5 | Noticeably rippled |
| 9 | Pure, clean tone |
How reports work in practice
The honest truth: Most operators give "59" (five-nine) on SSB and "599" (five-nine-nine) on CW regardless of actual signal quality. In contests, "59" or "599" is given to every station because the exchange must be fast. In casual contacts, honest signal reports are more useful but less common.
What "59" actually means: Readability 5 (perfectly readable), Strength 9 (extremely strong). This is the report most stations receive even when the actual signal is more like 55 or 44.
Giving honest reports: If a station is genuinely difficult to copy, say so: "You are 33 here — readable with difficulty and weak." Honest reports help the other station evaluate their antenna and power. Giving 59 to a station that is actually 33 does them no favors.
Contest reports: Always "59" or "599" regardless of actual signal quality. Contests use the exchange as a formality, not as genuine signal assessment. This is convention, not dishonesty.