El 09/03/2010 17:11, rein...@ix.netcom.com escribió: > Hello Jose, > > > Multiple Frequency Shift Keying, OK, but you really > did not answer my question, I think. > > Suppose I replaced the modulation device with a filtered > piano ( no harmonics ) a microphone. > I am serious, trying to find out the question we can't address > here any longer. > > I used a x-tal oscillator. > > Limited my BW to some 300 Hz > > > > 73 Rein W6SZ
Rein I failed to see the twist and I still do not see what you are after. I took "My Way" (MP3), played on the piano by Richard Claydermann, and processed it with Audacity, mixing it to mono, resampling to 11025 Hz, saved it as wav, and played it back thru both Spectran and HDWinrad, one at a time, both very steeply filtered, and what you hear are pings, tingling noises with a very slight trace of musicality. There are also some harmonics of the lower frequencies that bleed thru the filter, since their spectrum falls in the selected bandpass. Can you give any further hints? You might reproduce that yourself, without spending a lot of money and waiting for your filter to be made. 73, Jose, CO2JA
