Galina Mihaylova & Anton Ivanov

RS report, RST report, RSV report

RS report

On the telephone, the two correspondents exchange an RS report – a report on Readability and Signal Strength.

We have already mentioned that with telephony contacts, you should not overuse the Q-code, but if you use it, do it correctly. QRK stands for signal intelligibility, which is the same as the “R” in the RS report. QSA stands for signal strength, like the “S” in the RS report.

Caution! One thing is different and important: the S in the RS report varies between 1 and 9, while the QSA code can only be between 1 and 5. So don’t say: “Your QSA is 5 and QRK – 9 (as sometimes we can hear)”, and if you still want to use the Q code, say: “Your QRK is 5 and QSA 5”. Of course, it is much simpler to say “RS 59”. On CW, the use of QRK and QSA has almost disappeared. Instead, CW only uses the RST report (see CW below).

The strength of modern equipment can also be measured with an S-meter, the rest of the assessments are generally subjective. If there is no S-meter, the strength is also evaluated subjectively.

Grade for intelligibility and strength in RS report:

Readability Signal Strength
R1 Unintelligible S1 None, fading signal
R2 Almost unintelligible S2 Very weak signal
R3 Understandable with difficulty S3 Weak signal
R4 Understood without difficulty S4 Moderate signal
R5 Perfectly understandable S5 Acceptably good signal
S6 Good signal
S7 Pretty good signal
S8 Strong signal
S9 Very strong signal


Using the word “over” at the end of your line is recommended, but not required. A QSO consists of a series of transmissions (replies) or a series of “overs”. “over” replaces “transfer to you”.

If the signal strength is not very good and the intelligibility is not perfect, you can spell your name, for example: “My name is Tony, I spell tango oscar november yankee”. Do NOT spell it twice: “…tango tango oscar oscar november november yankee yankee”. This is not the way to spell the name Tony.

RST report

It has already been discussed that R and S are derived from “Intelligibility” (1 to 5) and “Signal Strength” (1 to 9) as used in telephony. T (1 to 9) in the signal report is derived from “Tone”. The number is an indicator of the purity of sound in the CW signal, which should be pure sinusoidal without distortion.

Official tone rating in RST rating:

T1 60 Hz (or 50 Hz) hum, extra coarse and wide
T2 Too harsh hum, very hoarse signal
ТЗ Rectified AC hum, but not filtered
T4 Broom, some signs of filtering
Т5 Filtered AC but heavily overmodulated tone
T6 Filtered tone, obvious traces of overmodulation
T7 Near clean tone, traces of overmodulation
T8 Near perfect tone, slight traces of overmodulation
T9 Perfect tone, no trace of overmodulation

The original descriptions evaluating the various cases of T date back to the early years of ham radio, when a pure CW tone was the exception rather than the rule. The table above descriptionva modern CW tone ratings as published in 1995 (source: W4NRL).

In practice, we do not use all official tone levels (T). This also fits the general state of technology today.

Modern practical use of tone rating in RST rating:

T1 deeply modulated CW, elements of wild oscillations, or extremely rough AC (means: get off the air with such a bad signal!)
T5 very noticeable AC component (often due to poorly regulated transmitter or amplifier power supply)




slight, barely noticeable AC component
T9 perfect pitch, undistorted sine wave

Nowadays, the most common defects of the CW signal are chirp and the even more common click or click of the switch (see below).

Chirps and clicks used to be very common problems with the CW signal: every operator knew that 579C was a report that meant a chirping signal, and 589K meant a key click. Few hams today know what the “C” and “K” at the end of the RST report mean, so you better transmit “CHIRP” or “BAD CHIRP” and “CLICKS” or “BAD CLICKS” in whole words as part of your report.

RSV report – used for SSTV

In SSTV operation, we do not exchange an RS report (telephony) nor an RST report (CW), but an RSV report, where V is derived from video and is an estimate of picture quality.

R (1 to 5) and S (1 to 9) have the same meanings as used on telephony and CW.

Evaluation of video signal in RCV report:

V1 Strong QRMs and image distortion, part of it indecipherable
V2 Heavily disturbed image, hard to read part of initial
V3 Medium image quality
V4 Good image, little distortion, little interference
V5 Image Perfect

RSQ Report

The traditional RST report is unsuitable for use in its original sense in digital broadcast classes such as PSK31 and easily leads many operators to use the popular 599 contention regardless of the true merits of the received signal. RSQ (Intelligibility, Loudness, Quality) has been adapted from RST to present a more valuable report at KB digital broadcast classes.

RSQ Comprehension: the detailed table (below) expresses the corresponding percentage of comprehensible text. This is in accordance with the common practice to exchange this percentage during each QSO.

RSQ Strength: most computer programs used in the KB broadcast digital classes provide monitoring of the entire signal spectrum. Hence, the apparent signal-to-noise magnitude has a greater value than the S-meter report, which averages the signal strength over the entire passband.

RSQ Quality: the presence of additional unwanted modulation traces in the signal spectrum are an indication of possible spurious emissions (mainly caused by overmodulation) and are a basis for evaluating the quality of digital signals.

RSQ Report.

R5 > 95% perfectly readable
R4 80% practically no difficulty, randomly missing characters
R3 40% significant difficulty, many missing characters
R2 20% randomly understood words
R1 0% illegible
S9 Very strong signal
S7 Strong signal
S5 Moderate signal
S3 Weak signal
S1 Almost unreceived signal
Q5 Clean signal – no unwanted side emissions
Q4 A hard-to-spot pair of unwanted emissions
Q3 An easily spotted pair of unwanted emissions
Q2 Multiple Pairs
Q1 Scattered across the spectrum

In most short, routine QSOs, you also describe your station and antenna. Outside weather information (which is related to passage, especially on VHF and up) can also be exchanged. As a rule, the station that was first on the frequency (for example, the one that called CQ) determines how the call proceeds. Maybe her desire is a very brief hello-goodbye relationship.

Even during a stereotypical QSO, technical discussions or the exchange of experimental results can often be picked up, just as one would in a face-to-face conversation. It is worth noting that many friendships have been forged as a result of radio contacts between hams. The hobby actually builds bridges between societies, cultures and civilizations!

Leave a comment

Your email address will not be published. Required fields are marked *