Until I began operating on the HF bands I was not well versed in how to respond to a signal report request during point to point communication, also known as simplex. For the training tonight I’d like to share some information I found related to signal reports, specifically the R-S-T system.
The R-S-T system is used by amateur radio operators, shortwave listeners, and other radio hobbyists to exchange information about the quality of a radio signal being received in point to point communication - without the aid of a repeater. The code is a three digit number, with one digit each for conveying an assessment of the signal's readability, strength, and tone.
Note: The assessment of the tone only pertains to Morse code and other digital transmission modes and is therefore omitted during voice operations.
Readability is a qualitative assessment of how easy or difficult it is to correctly copy the information being sent during the transmission. In a Morse code telegraphy transmission, readability refers to how easy or difficult it is to distinguish each of the characters in the text of the message being sent; in a voice transmission, readability refers to how easy or difficult it is for each spoken word to be understood correctly. Readability is measured on a scale of 1 to 5.
Unreadable
Barely readable, occasional words distinguishable
Readable with considerable difficulty
Readable with practically no difficulty
Perfectly readable
Strength is an assessment of how powerful the received signal is at the receiving location. Although an accurate signal strength meter can determine a quantitative value for signal strength, in practice this portion of the RST code is a qualitative assessment, often made based on the S meter of the radio receiver at the location of signal reception. "Strength" is measured on a scale of 1 to 9.
Faint—signals barely perceptible
Very weak signals
Weak signals
Fair signals
Fairly good signals
Good signals
Moderately strong signals
Strong signals
Extremely strong signals
An example RST report for a voice transmission could be "59", usually pronounced "five nine" or "five by nine", a report that indicates a perfectly readable and very strong signal.
Signals received through a repeater are assessed differently. Because the repeater’s output signal is modulated and a repeated version of the input, it is generally not helpful to rate the strength of the signal received. However, rating the quality of the input to the repeater is helpful - the “R” portion of the R-S-T system - but the rating is usually not expressed numerically. Instead, a report is returned as a verbal description of the signal.
For example, if the signal you hear from the repeater is free of static and perfectly readable, instead of assigning a 5 rating for the “R” portion of the R-S-T system, your report could be, “you are coming in loud and clear”, or “you are full-quieting”. If the signal does have static, or does not hold the repeater, the report returned is a verbal description based on the readability of the signal going into the repeater.
This concludes our training topic. As we proceed to our check-in tonight, I propose we practice returning a signal report. When each station is called, as part of your response, please give a report of how my signal was received at your location. I will also return with a signal report for each station that checks in to the net.