Tuesday, 23 March 2010

Amazing that Radio works at all

Think about this:
An S9 signal (50 microvolts) at the input terminal of an H.F. receiver with a 50 ohm input impedance, is 50 PICOWATTS. That's 50 TRILLIONTHS of a watt, for the prefix illiterate.

That's a STRONG signal.

An S1 signal, (assuming a standard of 6 dB per S unit) is down 54dB below that (almost six decimal places). That's in the QUINTILLIONTHS of watts!

(Thanks to KL7AJ on QRZ.com’s public forums)

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