No one is disagreeing. S-meters are renowned liars. Mind you, I have a CB set
(which has an AGC line) which is converted to 10m, and this has an S-meter
which has remarkably consistent 6dB S-points between S2 and S9 +20dB.

Even considering an ideal S-meter having a perfect one-S point-per-6 dB
response, the answer to the original question is that only in theory doubling
the transmit power turns into a 3-dB increase in S-meter reading.

In practice what the S-meter "measures" is the sum of the "wanted" signal power,
plus the background noise power (which on e.g. 160 meters could be quite high),
plus possibly the power other signals falling in the receiver bandwidth. If the
wanted signal is not strong enough to overwhelm al other contributions, doubling
the transmit power will not turn into a 3-db S-meter reading increase.

73

Tony I0JX, Rome Italy


:

If we double the power
radiated by an antenna (+3 dB), how does it translate on the S-meter
at a receiver 'far' away..