El 20/08/17 a las 22:21, Alex, VE3NEA escribió: > Of course, 400W should be the average power of the amplifier, not the > peak power. > > Splitting the power unevenly between the messages (in favor of the > callers on a difficult path) may improve the peak to average power ratio.
Or more interestingly, if the frequencies of the signals bear no simple relation then a large fraction of the time PAPR is not so high and not much is lost by bringing the amplifier a bit into compression. This is used in FreeDV 700C, where the PSK carriers use some well thought spacing instead of a multiple of the baudrate as OFDM would say. My guess is that if one puts 10 FT8 signals at random frequencies, then the signals are not so affected by compression in the amplifier. However, this would generate a lot of spurious signals as IMD. But still, if this is for a DXpedition working several caller simultaneously in a pileup we might deem all this IMD as a minor problem and end up seeing this as acceptable behaviour. This thing about transmitting several signals at the same time is quite interesting, since I haven't seen much done about it in ham radio. 73, Dani EA4GPZ. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
