Select the signal's most consistant characteristic from each of the R, S, and T columns in the chart. Select the number from the R-S-T Numeric Value (left) column which corresponds to each characteristic chosen. This R-S-T sequence of numbers becomes the RST signal report.
If the signal has the characteristic stability of crystal control, the
letter X may be added to the end of the RST report.
Use the the letter C to indicate a chirp on the signal.
Use the letter K for key clicks.
"RST is 599" - means that the morse code cw signal being assessed is Readability 5 (perfectly readable), Strength 9 (extremely strong signal), Tone 9 (perfect tone).
This is the ultimate (or "perfect") cw signal.
This reporting system may also be used for phone operation by leaving out the Tone (T) portion of the report. For example,
a signal of "5 9" means that the phone signal is Readability 5, and Strength 9; a perfectly readable and extremely strong signal.
The term "S-9" is also used to report a Strength 9 for an extremely strong signal.
If an S-Meter is being used as a basis of the signal report, an S-9 is the notation for 9 (S-Units) on the meter.