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 -----Original Message----- >From: "José A. Amador" <ama...@electrica.cujae.edu.cu> >Sent: Mar 9, 2010 1:26 PM >To: digitalradio@yahoogroups.com >Cc: rein...@ix.netcom.com >Subject: Re: [digitalradio] Re: Question for experts > >El 09/03/2010 03:55 p.m., rein...@ix.netcom.com escribió: >> Hello All, >> >> Suppose I would build an transmitter with a x-tal oscillator, lets say >> running at 7040.000 Hz >> >> Part of the system was a balanced modulator and just to make sure a >> a high quality crystal filter, with a 1:1.05 shape factor, was added >> in the driver stages for the final amplifier. >> >> With a lot of tweaking a carrier suppression of the balanced >> modulator was reached of 67.3 dB and the balanced modulator >> was kept temperature stabilized within .1 degree Fahrenheit. >> >> On the modulation section, I constructed a tone generator which could >> be changed in steps of 7.3 Hz starting from 1354 Hz to all the way up >> to 1646 Hz. >> >> I went out and got the xtal filter ordered for a lot of money. >> >> Center frequency of xtal filter ordered and delivered for 7041.500 Hz >> filter at - 80 dB BW 500 Hz. >> >> My question is what would the modulation be of this transmitter? >> >> The amount of audio was set in such a way that the output of >> the transmitter had no distortion what so ever totally >> linear! >> >> 73 Rein W6SZ >> > >All that trouble for MFSK ? :-) > >73, > >Jose, CO2JA > > > > > > >------------------------------------ > >Try Hamspots, PSKreporter, and K3UK Sked Page >http://www.obriensweb.com/skedpskr4.html >Suggesting calling frequencies: Modes <500Hz 3583,7073,14073,18103, >21073,24923, 28123 . Wider modes e.g. Olivia 32/1000, ROS16, ALE: 14109.7088. >Yahoo! Groups Links > > >
