RE: [Amps] 10 DB increase

["Bob Alexander" <realex@flash.net>]

I went back to the archive to find the original question.
S-meters do not measure received signal level accurately because they do not
measure the signal but rather the level of the AGC voltage required to
maintain
a constant audio level output.

Most S-neters are adjusted to provide an S9 indication with a specific input
signal
level at the antenna terminals...usually around 50 uV.  A 10 dB decrease in
this signal
leaves 15.8 uV at the antenna while a 10 dB increase results in 158 uV at
the antenna.
Remember we are talking voltage not power.

The AGC/ S-meter system is different in every receiver.   Even two identical
receivers may require a slightly different change in voltage to provide the
same
degree of AGC action.  It depends on alignment. Also, look at the scale on
the meter.
It should be logarithmic not linear.

The bottom line is that the voltage is sampled and "converted" to what we
consider
to be accurate meter readings. That may or may not be the case.

73, Bob, W5AH


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