Thread: AGC Design?
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Old May 26th 05, 06:57 PM
Tom
 
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Telamon, those are interesting numbers, expressing the action of a more
sophisticated, programmable, digital AGC. Classic analog AGC speeds are
expressed as the length of time it takes to reach a certain percentage
or within a few dB of the desired gain setting, i.e., similar to and
based on RC time constants as that was the foundation of the classic
AGC control system. With an RC derived control, whether the gain change
is 10 dB or 100 dB, it takes the same time. With your digital control
in 'Fast' mode, attack would be 8ms for 10 dB and 80 ms for 100 dB;
release would be hang time plus 6ms or 60 ms respectively. It's
interesting how these compare with my target of 1-13 ms attack, 25-50
ms release.

I'm wondering how your RX340 behaves when you program to 0.01 dB/ms
attack, 0 hang, and 1600 dB/s decay (but I see that the programmable
decay is limited to 99.9? probably for good reason!). That would
correspond to my Fast target when you tune from no signal to S9+50.

Regards,

Tom