RadioBanter - View Single Post

Jon LA4RT · September 17th 08, 08:52 AM posted to rec.radio.amateur.antenna

writes:

John, Quiz Question: Suppose you tried to modulate a 14 Khz carrier
with a 50MHz digital signal. Would that be possible? (Y/N) Where would
you locate the side bands? (________ and ________)

If we interpret this as a signal occupying the spectrum from DC to 28
kHz, we need about 1800 bits/Hz. Mathematically, this isn't
impossible, but according to the Shannon/Hartley theorem, we need an
SNR of 2^1800, or more than 5400 dB. Assuming noise of -120 dBm, the
signal has to 5250 dBW, og 10^525 W. Making detection circuitry work
at this power level would be a challange, as it is the equivalent of more
than 10^498 suns, 10^486 milky ways or 10^475 observable universes.

73
Jon LA4RT