Posted by
wayne burdick on
May 13, 2018; 2:43am
URL: http://elecraft.85.s1.nabble.com/P3-display-versus-FlexRadio-tp7640821p7640823.html
Hi Jim,
They may be automatically calculating a long-term-average noise floor, then subtracting it from the waterfall. The P3 could do the same thing. But automatic noise subtraction would have the same disadvantage as slow AGC: a temporary rise in the noise floor would mask weak signals for the duration of the averaging time constant.
You can achieve the same thing manually, without the averaging issue. Simply adjust the REF level such that the noise floor is just at or slightly below the line. The waterfall will then be nearly invisible except for signals and higher noise peaks.
Wayne
N6KR
----
http://www.elecraft.com> On May 12, 2018, at 5:54 PM, Jim N7US <
[hidden email]> wrote:
>
> I saw a demo last night of the FlexRadio bandscope. It showed the noise
> well above, on the Y-axis, the bottom of the display, but the waterfall
> didn't show the noise, just the signals on the band.
>
>
>
> When I set the REL LVL on my P3 so the noise floor is below the noise, the
> waterfall is blue from the noise, making it difficult to see the signals.
>
>
>
> Can someone enlighten me as to why the displays are so different?
>
>
>
> 73, Jim N7US
>
>
>
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