The other problem is linearity of the whole chain. The subcarriers get mixed not only in the PA, but in the receiver, sound card etc., which may be interpreted as increased noise on the decoder side. The average YaeComWood was not designed with this in mind. Voice SSB modulation is roughly similar to three carriers.
So using multimulticarrier soundmodem with a YaeComWood + 1kW PA will only heat your ham shack without other useful effect. 73, Vojtech OK1IAK --- In digitalradio@yahoogroups.com, "Patrick Lindecker" <[EMAIL PROTECTED]> wrote: > > Hello to all, > > For me, the main problem, for Hams, of the multi-carriers modulation (OFDM...) is that the power is drastically limited (if you want to, legitimally, keep linear): > > If you have two carriers in parallel, the mean power/max power ratio is equal to 1/2 > If you have three carriers in parallel, the mean power/max power ratio is equal to 1/3 > ............................ > when n becomes big, the ratio tends to 1/square(n) (the carriers phases being independant, with application of the "big numbers law") > For example, for MT63 where you have 64 carriers in parallel, the ratio is 1/8. You transmit only 12.5 watts with a 100 watts maximum XCVR.
