Hello All -

This reads like a tongue-in-cheek bit of good-natured trolling... but I have
added a few comments, just in case some newbie takes it all too seriously.

"Reg Edwards" wrote in message
...

S-meters are nothing else but power (input) meters.

Actually, the tradition has been to characterize S-meter calibration
(if I may call it that) in terms of voltage, not power. Of course, the
two may be translated freely if one assumes an input impedance.

More significantly, the typical signal-strength indicators on receivers
are not ANY kind of "meters"--in the sense of comprising calibrated
test equipment. A minority of higher-end receivers MAY receive a
quick stab at meter calibration in the alignment process; and they MAY
have flat enough gain versus frequency for that calibration to apply
roughly across their frequency coverage. But I wouldn't count on it.

Amateurs and meter manufacturers long ago learned, that when giving signal
strength reports, it is more convenient to refer to meter indications in
terms of S-units rather than micro-watts or nano-watts.

Amen to that.

At HF, when the meter reads S-9 the power entering the receiver is 50
pico-watts. There's a slight complication above S-9 when the meter scale
changes to decibels above S-9.

The "at HF" qualifier is curious, since the propositions are not frequency
dependent. But 50 pW does indeed match up to the traditional 50 uV,
if I did my math right.

When the reading is S-9 plus 40 dB the meter is actually indicating about
S-16. It's just a matter of scale graduations and printing.

A very important omission here is the traditional assumption that each
S-unit should represent a 6 dB change. My FT-1000D shows substantial
departures from this ideal, BTW.

But since the S-unit scale is an attempt to quantify the S1 through S9 range
of the classic RST signal reporting scheme, there is no such thing as "S
units" above S9, the highest. Hence the "dB over" nomenclature.

The S-meter does NOT measure or even indicate field strength. It
indicates nothing except that an increase in meter reading corresponds
to an increase in field strength. Which may be nice to know but by
how much of an increase is anybody's guess.

This is more realistic, although nits could be picked.

Measured field strength depends on the type of antenna, its efficiency,
ground losses, etc. It is possible, of course, to calculate field
strength in the vicinity of the antenna from S-meter readings provided
the antenna, its directivity, transmission line, tuner and ground
characteristics are all known numerically. Which in the amateur
situation they are seldom not! Or even in the professional situation.

You've all got one. To repeat - the S-meter is a power (input) meter.

S-meters are relative signal strength indicators. Some of them MAY match
the "ideal" response at a few input levels and input frequencies.

----
Reg, G4FGQ