The RST System

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 ac or less, very rough and broad.
  2. Very rough ac, very harsh and broad.
  3. Rough ac tone, rectified but not filtered.
  4. Rough note, some trace of filtering.
  5. Filtered rectified ac 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.

If the signal has the characteristic steadiness of crystal control, add the letter X to the RST report. If there is a chirp, add the letter C. Similarly for a click, add K. The above reporting system is used on both CW and voice; leave out the “tone” report on voice.

The correct way of using the RST system is often misunderstood on 11 meter band. You should select the signal’s most prominent characteristic from each of the R, S, and T columns in the chart, also for the signal!

You should not use your signal meter as basis for the signal report, because your signal meter is not calibrated to follow the RST system.

Signal zero means no radio at all!