AM modulator with MC1496 project problem

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Thread Starter


Joined Jun 3, 2007
Hello, i have done this project. It is an experimental oscillator - modulator for mw frequencies. The schematics are here:

The problem is that the designer told me to use an 1kohm variable series resistance between oscillator and modulator (after

c9=22n capacitor of oscillator) to adjust the carrier level. I saw that the 1kohm variable series resistance is not enought

because with 1kohm series resistance the audio was't very good. I think that the carrier level was high. So i change this

resistance with another 4.7kohm. Now i am using about 2kohm of this series resistance. The modulation is very good But i

think that the audio signal in the radio is not at the center of the frequency but a little above.
(The operation frequency is 1000khz but i listen the audio with quality and strong voice at 1003khz.)
which is the problem? how i can fix it, to listen the audio very well at center frequency and not at sideband?
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