you mean something similar like a 25Hz pilot tone for C-QUAM AM Stereo ?
as it is now, i have to generate my own 25Hz pilot tone for C-QUAM outside of using ST so the tone does not affect ST processing.
Hello! Glad to have your reply. I didn't mean to add the function of "Pilot Tone". Let me describe it more, shall I?
First of all, forget about AM stereo and think of a normal mono AM transmitter instead. Nonetheless, the difference is that such transmitter doesn't generate carrier signal (similar to SSB). Thus, an AM receiver cannot demodulate the sound correctly, but you can use a receiver capable of demodulating SSB signal to hear clear sound. So, theoretically, we need to supplement a virtual 0 Hz carrier signal for the transmitter.
0 Hz signal cannot be generated by any software and soundcard. If we suppose that Stereo Tool (ST) could fully functional in generating the carrier signal, we could at least generate any carrier signal above 1 Hz, say +5 kHz. Accordingly, we could shift down the intermediate frequency (IF) by 5 kHz. As long as ST also shift all the input (voice signal) up by 5 kHz, we could hear the voice through normal AM radio.
Here, there might be another problem occur: a pair of symmetric signals appear simultaneously mirroring around the IF. So ST should suppress the mirror signal in order to obtain the purely true AM signal.
Hope that my lengthy explanation can make some help.