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