Re: Slow t/r receive recovery #ubitxcw



I just pulled up excel to do a quick calculation.  The time constant for an RC circuit is T = 1 / (R*C).  note this is the time to reach 67% of steady state value, but gives us a feel for responsiveness. 

T = 1 / (680000 * 2.2 * 1E-6) = 0.67 seconds.

Now defining when this AGC circuit sounds finished to your ears, it could be longer than 1 second.  Use it as a figure of merit to start with. 

If you divide either the R or C by 2, it should settle twice as fast.  maybe select a couple values and use a SP2T to select between them. 

I confess I have no clue the fast and slow AGC times of a typical rig, but you could pick a rig type and see what it lists in manufacturer's spec or a on-line review. 

I do remember seeing the QST article - but I had already installed the VK3YE circuit that I am happy with.  Enjoy your experimenting. 


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