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
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
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
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
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.
R or Readability
1 | Unreadable |
2 | Barely readable, occasional words distinguishable |
3 | Readable with considerable difficulty |
4 | Readable with practically no difficulty |
5 | Perfectly readable |
Strength
1 | Faint signal, barely perceptible | HF=-121 dBm | V/UHF=-141 dBm |
2 | Very weak | HF=-115 dBm | V/UHF=-135 dBm |
3 | Weak | HF=-109 dBm | V/UHF=-129 dBm |
4 | Fair | HF=-103 dBm | V/UHF=-123 dBm |
5 | Fairly good | HF=-97 dBm | V/UHF=-117 dBm |
6 | Good | HF=-91 dBm | V/UHF=-111 dBm |
7 | Moderately strong | HF=-85 dBm | V/UHF=-105 dBm |
8 | Strong | HF=-79 dBm | V/UHF=-99 dBm |
9 | Very strong signals | HF=-73 dBm | V/UHF=-93 dBm |
Tone
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:
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
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
1 | barely perceptible trace |
3 | Weak trace |
5 | Moderate trace |
7 | Strong trace |
9 | Very strong trace |
Quality
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 |