You may have noticed that the well-known program WSJT displays the signal-above-noise level in decibels. It's an interesting game of decibels... But what about in normal operation (CW/SSB)? The accuracy of S-meters tends to be very poor, but in case you are asked to compare signals by a counter station doing some experiment, you have a very accurate measuring device at your disposal.
And that's human hearing. The following table will show how, for example, replacing a coaxial cable with a low-loss one, increasing performance, etc. With antennas, it's a little different, the result is influenced by several factors of the antenna itself.
| Gain in dB | It seems like |
| 1 f 3 | just noticeable increase in signal strength |
| 3 | an easily noticeable increase in signal strength |
| 6 | doubling the sound level |
| 10 | significant increase in signal strength |