"Jay R. Ashworth" wrote: > > For example: > > distance from Earth to Moon = ~384000km, > > then : > > > >> 41 dBm EIRP (20dBm + 21dBi) at his house. > > > >> - 108 dB Free space loss - first link > > Free space loss from Earth to Moon = -227dB > > > >> + 18 dBi antenna gain on the mountain. > > > >> + 18 dBi antenna gain on the mountain. > > > >> - 118 dB Free space loss - second link. > > Free space loss from Moon to Earth = -227dB > > > >> + 24 dBi antenna gain at ISP. > > > >> ========= > > > >> - 125 dBm > > total : - 454 dB Free space loss ... > > Communication impossible, > > even if to use "1Hz or less bandwidth" > > & "symbol rate is about one symbol every 10 seconds" > > And yet, hams have been doing successful EM or 'moonbounce' > communications since, ok, the 60's or earlier. Curious, isn't it? > Perhaps your math is wrong?
Not, my math exact ;) wrong twice to add (Free space loss - first link)+(Free space loss - second link) only one ... for Moon bounce Free space loss = -234 dB > http://directory.google.com/Top/Recreation/Radio/Amateur/VHF/Moonbounce/ If Free space loss = -234 dB it is possible :) -Ivan > Cheers, > -- jra > -- > Jay R. Ashworth [EMAIL PROTECTED] > Member of the Technical Staff Baylink RFC 2100 > The Suncoast Freenet The Things I Think > Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274 > > Come see Linux Gazette in our new home: www.linuxgazette.net! > -- > general wireless list, a bawug thing <http://www.bawug.org/> > [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
