| READABILITY | |
| 1 | Unreadable |
| 2 | Barely readable; only occasional words distinguishable |
| 3 | Readable but with considerable difficulty |
| 4 | Readable with practically no difficulty |
| 5 | Perfectly readable |
| SIGNAL STRENGTH | |
| 1 | Very faint signals |
| 2 | Very weak signals |
| 3 | Weak signals |
| 4 | Fair signals |
| 5 | Fairly good signals |
| 6 | Good signals |
| 7 | Moderately strong signals |
| 8 | Strong signals |
| 9 | Extremely strong signals |
| TONE | |
| 1 | A sixty-cycle hum is present on the signal. Very rough and raw to listen to |
| 2 | Very rough, harsh and broad a.c. hum is present on the signal. |
| 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 note, no trace of ripple or modulation of any kind. |
R = Readability