Hmm...may be true, may not be. We'll have to wait and see!
Since the rectified HF signal is essentially AVC, you could tap into it and bias it for electronic volume control, couple in some audio (plus a shaping circuit for log/exp. AVC response) for compression or expansion, etc. Hmmm...
Tim
Since the rectified HF signal is essentially AVC, you could tap into it and bias it for electronic volume control, couple in some audio (plus a shaping circuit for log/exp. AVC response) for compression or expansion, etc. Hmmm...
Tim
different perspective
Chapter 2.5 .1.2.6.1.4.2.1...
Thinking about this a little more, I think one could look at the gain control feedback loop (in the gain multiplier designs, including the dither design) as a simple classical control system that is trying to maintain a setpoint versus external interfering influence (the input signal excercising different operating points with slightly different gains). So what is needed is critical damping in the gain control loop to minimize the residual effects of control level changes. Also, the correct gain to maintain accurate setpoint.
So distortion correction effects would still have some trailing influence somewhat like in conventional NFB loops, but I think this would be a very small effect for a well designed amplifier due to the small level of change of gain except near saturation. So the (multiplier) control level is hardly changing for large signal variations. Also, the effect of a critically damped bounce in the control level may simply allow some uncorrected distortion thru rather than generating new higher harmonics, but would need to simulate or test this. Generally though, for a control system that is fast compared to the stimulus signal, the effect of changing input is to just generate a small slew related lag error in the control level, and this should not be a problem. I think! (Darn, where's that control system book from 30 years ago?)
Don
Chapter 2.5 .1.2.6.1.4.2.1...
Thinking about this a little more, I think one could look at the gain control feedback loop (in the gain multiplier designs, including the dither design) as a simple classical control system that is trying to maintain a setpoint versus external interfering influence (the input signal excercising different operating points with slightly different gains). So what is needed is critical damping in the gain control loop to minimize the residual effects of control level changes. Also, the correct gain to maintain accurate setpoint.
So distortion correction effects would still have some trailing influence somewhat like in conventional NFB loops, but I think this would be a very small effect for a well designed amplifier due to the small level of change of gain except near saturation. So the (multiplier) control level is hardly changing for large signal variations. Also, the effect of a critically damped bounce in the control level may simply allow some uncorrected distortion thru rather than generating new higher harmonics, but would need to simulate or test this. Generally though, for a control system that is fast compared to the stimulus signal, the effect of changing input is to just generate a small slew related lag error in the control level, and this should not be a problem. I think! (Darn, where's that control system book from 30 years ago?)
Don
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