Need testers for improved K3 AGC (specifically for pileup conditions)

[wayne burdick]

Hi all,

We've significantly improved the K3's DSP AGC based on feedback from  
DXpedition users. In some cases, dozens of stations with nearly  
identical amplitude may be packed together into just a few tens or  
hundred of Hz of bandwidth. The AGC threshold can now be set much  
higher, allowing "headroom" for such signals. Any nonlinearities due  
to DSP AGC can thus be avoided for signals as high as about S9.

At the same time, we've eliminated the slightly "scalloped" (non-
monotonic) AGC curve noted by one reviewer. This was caused by  
interpolation errors in the DSP's fast log and anti-log functions,  
which are now orders of magnitude more precise. The resulting AGC  
curve is very smooth, so signals right at the threshold can't be  
modulated by AGC onset.

If you'd be interested in helping us evaluate these changes, or if you  
know of someone who might benefit, please email me directly.

73,
Wayne
N6KR

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[Scott Manthe-2]

Maybe those fellows at 7O6T?   ;)

73,
Scott, N9AA


On 5/5/12 5:28 PM, Wayne Burdick wrote:

> Hi all,
>
> We've significantly improved the K3's DSP AGC based on feedback from
> DXpedition users. In some cases, dozens of stations with nearly
> identical amplitude may be packed together into just a few tens or
> hundred of Hz of bandwidth. The AGC threshold can now be set much
> higher, allowing "headroom" for such signals. Any nonlinearities due
> to DSP AGC can thus be avoided for signals as high as about S9.
>
> At the same time, we've eliminated the slightly "scalloped" (non-
> monotonic) AGC curve noted by one reviewer. This was caused by
> interpolation errors in the DSP's fast log and anti-log functions,
> which are now orders of magnitude more precise. The resulting AGC
> curve is very smooth, so signals right at the threshold can't be
> modulated by AGC onset.
>
> If you'd be interested in helping us evaluate these changes, or if you
> know of someone who might benefit, please email me directly.
>
> 73,
> Wayne
> N6KR
>
>

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Please help support this email list: http://www.qsl.net/donate.html