Relative to a receiving antenna's signal: what does the receiver
actually
respond to; power or voltage at its input ?

Bob

--------------------------------------------------------------

The S-meter is actually a wattmeter. S9 = 50 pico-watts into a
50-ohms receiver input impedance.

It indicates signal strength and strength is watts.

A typical meter is scaled from -54 dB to +50 dB relative to S9.

That's why S9 is roughly half way along the scale - about 50 dB on
each side of it.

-54 dB corresponds roughly to receiver internal noise level.

+50 dB corresponds to receiver overload level.
----
Reg, G4FGQ