While the DSP can't help the receiver's AGC, it can have its own AGC.
The Timewave DSP-59+ that I use has an AGC function that works well.
When used with the noise reduction function it often helps me to copy
very marginal signals that are just detectable without it. Unfortunately
that AGC function has a very short time constant and it brings up the
noise that the noise reduction function audibly removed. Just that the
resulting signal to noise ratio, if there was any signal at all has been
significantly enhanced. It won't make a signal copyable that wasn't
audible before the processing though. Doesn't have enough dynamic range
to pick signals from way below the noise.
73, Jerry, K0CQ
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