Digital Mode Signal Reporting

The Problem

Digital modes such as PSK have been around for a long time but it appears only a few amateurs have adopted the RSQ (Readability, Strength, Quality) signal reporting method which is much better suited to digital modes where we can't use our hearing to assess the signal.

The RST (Readability, Strength and Tone) works well for Voice and CW but is impossible to apply to narrow signals such as PSK. We typically get a 3kHz wide signal into our software where we watch the waterfall and pick out one of many traces trickling down the waterfall. If we were to listen to the 3kHz wide audio we can hear all traces at once and can not picking the audio of the other station. The PSK31 signal is only 31Hz wide.

So we can't assess the T(one) nor can we assess the S(ignal) quantitatively as the S-Meter is going to display the average of all traces nor can we assess it qualitatively as we can't hear the individual trace.

Readability could be assessed by looking at the decoded test but the 1-5 scale (Unreadable, Barely Readable, Readable with difficulty, Readable, Perfectly Readable) is a very subjective description.

The Current Way

Most of use 599 as the standard report and add additional information at some of the QSO. The 599 indicates nothing more than "Yes , my signal is being decoded", it doesn't tell us anything about the real signal quality. The most common addition we often see is a percentage figure to indicate how much of the transmission is decoding correctly.

The Better Way

The RSQ system overcomes many of the problems listed above.

 Perfectly readable 
 Practically no difficulty, occasional missed characters
 Considerable difficulty, many missed characters
 Occasional words distinguishable
  S9   Very Strong trace
  S7   Strong trace
  S5   Moderate trace
  S3   Weak trace
  S1   Barely perceptible trace
  Q9   Clean signal - no visible unwanted sidebar pairs
  Q7   One barely visible pair
  Q5   One easily visible pair
  Q3   Multiple visible pairs
  Q1   Splatter over much of the spectrum

The credit for this table goes to Graeme VK3GN - please visit this website for acknowledgements.
You can read more about theRSQ system at

I would encourage everyone to use the RSQ system to provide better and more meaningful signal reports to other stations.