On Fri, 2006-11-03 at 22:37 -0800, Jerry Volpe wrote:
> I can see that this is yet another thread where people become quickly
> 'polarized' and somewhat 'territorial' so this is my last posting on
> this subject.
>
<SNIP>
> The Orion's notch filter operates at the audio portion of the DSP chain
> of software functionality. With version 2.x firmware the Orion started
> using an IF AGC detection scheme which has fewer general design 'issues'
> than the AGC derived from audio detection used in version 1.x. Because
> of this change the notch function must remain outside the AGC loop. For
> my conversations with the engineers involved this is not an issue that
> they will 'fix' or change as what ever you might gain in one area you
> will loose in the other. Frankly, I am very use to the version 2.x AGC
> system and I especially appreciate having the choice of two AGC slope
> factors which we didn't have with version 1.x. I don't like 'flat' which
> is all we had in version 1.x.
Perhaps there needs to be audio notch filtering for the ear and a
similar IF notch based on the audio notch for the IF AGC. Maybe there
need to be an audio AGC after all the processing to level the audio
output despite the effects of notches and filter rejection. More
complexity, but unless the DSP is running out of capability it should
all be possible. More is possible at the cost of increased latency in
the processing chain. To much delay makes manual tuning weird. Like
tuning through a rubber band drive.
>
<SNIP>
> 73,
>
> Jerry, KG6TT
> Fairfield, CA
>
>
--
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer
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