From: John Fields
Organization: Austin Instruments,Inc.
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Subject: Re: dBm and Microvolt/meter
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NNTP-Posting-Date: Wed, 02 Oct 2002 08:20:03 CDT
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Date: Wed, 02 Oct 2002 13:20:03 GMT
> << Check out http://www.astron.nl/craf/conv.htm >>
> Ok! Checked that out. Interesting, but 3uV and 3uV/meter are not the same
> thing. If I use a signal generator to put a .3uV signal into the 50 Ohm input
> of a receiver, I have put in a 96dBm signal.
Well, considering 0dBm to be 1mW, your 96dBm signal would place about
4MW into the 50 ohm input of the receiver, which translates into about
14kV across the receiver's input. Not a good thing to do unless the
receiver has _extremely_ low sensitivity.
As for the rest of it, you're obviously clueless. Specifying a
receiver's sensitivity in terms of field strength was done years ago
(and from the OP's post is still being done) and presupposes a certain
antenna connected to the receiver's RF input which, when intercepting
the electric field of an RF signal, resulted in a voltage being
presented at the receiver's input which caused a certain set of
conditions to result downstream in the receiver. dB of quieting in an
FM receiver, for example.
Professional circuit designer