The AD633 IC is a four-quadrant analog multiplier with differential X and Y inputs, and a high impedance summing input (Z). with the Z input connected to the carrier we obtain a double sideband full carrier modulated signal (DSBFC), if the Z input is connected to the ground the modulator produces a Double-sideband suppressed carrier signal (DSBSC) eliminating the carrier and transmitting the sidebands only. Here it's tested in both mode with a speech txt file as input signal.
I got it to run with Orchad Capture 16.6 on Win7. Excellent. This project is exactly what I was looking for. I could find out why in my own test modulation circuit annoying convergency errors came up. It seems that simulation is limited to a frequency range which is dependent on the used model. So I checked to modulate with 576 kHz - I am still not able to this neither with AD633 model from tobytone nor with that original AD model which is available on this site either. But the same circuit is running with 300 kHz without problem - alterning sim settings does not help. Anyhow I am confident to use the AD633 for modulation purposes. Thanks a lot tobytone!
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