Will take a look at URL:
http://www.ac6v.com/sunit.htm


Maybe the National Semiconductor NE604 IF amplifier IC would be worth
looking into. Claims say it provides an accurate signal strength logarithmic
output that closely tracks the input signal level over a wide dynamic range
that could possibly be used for driving an S meter circuit.

--
CL -- I doubt, therefore I might be !


"Will" wrote in message
...
I was wondering how commercial equipment go about calibrating the S meter
and whats the best way of building a calibrated S meter that would be
reliable as a professional field strength meter?

Since most S meters just read AGC voltage and it would be easy to build
some interface with a CPU to read voltages and calibrate this way. The
question is this, is a S meter calibrated this way actually reading in a
accurate way whats occurring at the antennas terminal. Since most antenna
inputs are not 50 ohms J0, how would you design a system like a spectrum
analyzer that measures signal voltage at the antenna terminal?. I would be
interested in some ideas, i am homebrewing a shortwave receiver however i
wanted a calibrated S meter in Dbuv, Dbm, S units and Millivolts. I also
want to use a calibrated antenna for a Antenna factor input to have a
meaningful long term view of propagation signal strength.

Thanks
Will