CSQ Summary
The following is a proposal from Bruce Prior N7RR for a signal reporting system based on Copyability-Strength-Quality (CSQ)
, and as an alternative to the traditional Readability-Strength-Tone (RST) system.
C or Copyability
| Copyability | Description |
|---|
| N | no recoverable signal \(^{*}\) |
| 0 | discernable but not copyable \(^{*}\) |
| 1-9 | 10% to 90% copy |
| G | Good 100% copy, but short of perfect |
| P | Perfect armchair 100% copy or full quieting on FM |
\(^{*}\) For Copyability reports of N and 0, no Signal Strength or Quality reports are needed.
S-Meter or Signal Strength
| Strength | Description |
|---|
| 0 | no S-meter reading |
| 1-9 | S-1 to S-9 |
| A | 1 dB to 10 dB over S-9 |
| B | 11 dB to 20 dB over S-9 |
| C | 21 dB to 30 dB over S-9 |
| D | 31 dB to 40 dB over S-9 |
| E | 41 dB to 50 dB over S-9 |
| F | 51 dB or more over S-9 |
Quality
| Quality | Description |
|---|
| X | characteristic steadiness of crystal (Xtal) control or eXcellent quality |
| R | AC Ripple or buzz in transmission |
| C | Chirp or tail on make and/or break |
| K | key clicKs or other Keying transients |
| O | Overmodulation or Overdeviation in phone or digital modes |
Examples
| Report | Description |
|---|
| P6O | for a PSK-31 signal: perfect 100 % copy at S-6, but overdeviated |
| 93X | for a CW signal: 90 % copy at S-3 with excellent quality |
| G7O | for an SSB signal: Good but less than perfect 100 % copy at S-7, but overmodulated |
| PAX | for an RTTY signal: perfect 100 % copy about 10 dB over S-9 with excellent quality |
| P6X | for an FM signal: full-quieting 100 % copy at S-6 with excellent quality |
RST Summary
For comparison with the proposed CSQ system, here are the definitions for the traditional RST system.o
R or Readability
| Readability | Description |
|---|
| 1 | Unreadable |
| 2 | Barely readable, occasional words distinguishable |
| 3 | Readable with considerable difficulty |
| 4 | Readable with practically no difficulty |
| 5 | Perfectly readable |
Strength
| Strength | Description | HF Signal | V/UHF Signal |
|---|
| 1 | Faint signal, barely perceptible | -121 dBm | -141 dBm |
| 2 | Very weak | -115 dBm | -135 dBm |
| 3 | Weak | -109 dBm | -129 dBm |
| 4 | Fair | -103 dBm | -123 dBm |
| 5 | Fairly good | -97 dBm | -117 dBm |
| 6 | Good | -91 dBm | -111 dBm |
| 7 | Moderately strong | -85 dBm | -105 dBm |
| 8 | Strong | -79 dBm | -99 dBm |
| 9 | Very strong signals | -73 dBm | -93 dBm |
Tone
| Tone | Description |
|---|
| 1 | Fifty 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 |
The following letters can be optionally suffixed:
| Suffix | Description |
|---|
| X | stable frequency (crystal control) |
| C | “chirp” (frequency shift when keying) |
| K | key clicks |
RSQ Summary
For digital work, the Readability-Strength-Quality signal reporting system is sometimes used.
R or Readability
| Readability | Description |
|---|
| 1 | 0 % copy - undecipherable |
| 2 | 20 % copy -occasional words distinguishable |
| 3 | 40 % copy - readable with difficulty, many missed characters |
| 4 | 80 % copy - Readable with no difficulty |
| 5 | 95 % + copy - Perfectly readable |
Strength
| Strength | Description |
|---|
| 1 | barely perceptible trace |
| 3 | Weak trace |
| 5 | Moderate trace |
| 7 | Strong trace |
| 9 | Very strong trace |
Quality
| Quality | Description |
|---|
| 1 | splatter over much of the spectrum |
| 3 | multiple visible pairs |
| 5 | One easily visible pair |
| 7 | One barely visible pair |
| 9 | Clean signal - no visible unwanted sidebars |