Created in 1934 by Arthur W. Braaten, W2BSR, the R-S-T- system we use today in ham radio lives on and is used daily by thousands of ham radio operators. It was designed to give operators a standard for reporting how a signal is transmitted or received.
When you are in the hobby, at some point, and mainly on HF and CW, you will be given or asked for a signal report with the person you are communicating with. The chart below is your guide to understanding what these report elements mean.
If talking on the radio with your mic, often you will give a two number signal report from the readability and Signal Strength sections of the chart below. For instance, if the signal is really good, no background noise and you hear the person loud and clear, you would give a signal report of 59 or 5/9. Adversely, if you can hear and understand the person, but you have static or a decent amount of noise, you may give them a rating of say 44 or 4/4.
There is an actual order to using the chart below. I have numbered them accordingly so that you can follow along and memorize them. I say memorize, however, over time you will just know what report to give to another ham you are talking with by “feeling” it out so to speak. Generally you will use charts 1 & 2 on voice or phone and 1, 2, & 3 on CW or Morse code conversations
2–Barely readable, occasional words distinguishable.
3–Readable with considerable difficulty.
4–Readable with practically no difficulty.
1–Faint signals, barely perceptible.
2–Very weak signals.
5–Fairly good signals.
7–Moderately strong signals.
9–Extremely strong signals.
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.
***If the signal has the characteristic steadiness of crystal control, add the letter X to the RST report. If there is a chirp, the letter C may be added to so indicate. Similarly for a click, add K. The above reporting system is used on both cw and voice, leaving out the “tone” report on voice. Turn card over for examples.