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 -----Original Message----- >From: "José A. Amador" <ama...@electrica.cujae.edu.cu> >Sent: Mar 9, 2010 11:57 AM >To: digitalradio@yahoogroups.com >Subject: Re: [digitalradio] Re: 1976 FCC - Delete all Emission Types from >Part 97 > >El 09/03/2010 02:08 p.m., KH6TY escribió: >> >> Using FSK instead of AFSK means you can run a big amp Class-C and get >> more power output. Also, you do not have to worry about preserving >> linearity on a Class-AB or Class-B amplifier if running FSK,or figure >> out how to interface the computer to the rig for AFSK. > >You can also run a saturated amplifiers chain with AFSK, if the envelope >does not vary. FSK, OQPSK, whatever has a flat envelope. >And not only class C, but also class D, E, F... > >73, > >Jose, CO2JA > >
