[TenTec] Orion II roofing filters

[Martin, AA6E]

Yes, I could have been clearer.  There are different "bands" or
passbands to consider.

Say you are working CW with the stock 1 kHz roofing filter and you
have the DSP BW set to < 300 Hz (assume no PBT).  If you are trying to
dig out a weak signal, and there is very strong QRM inside the 1 kHz
roofing passband, but outside the central 300 Hz, then the 300 Hz
roofing filter should help. Otherwise, the 1 kHz filter should be just
as good as the 300.

At this point, it helps to draw a picture...  I have a few in a talk I
gave early this year: http://www.aa6e.net/aa6e/orion-MARC/img9.html
and following.

73, Martin AA6E

On 12/27/05, Ken Brown <ken.d.brown at verizon.net> wrote:
>
> >  The extra filters add
> >nothing unless you have bad out of band QRM.
> >
> >
> A better IF filter can help with out of band QRM??? What do you mean by
> out of band QRM? I would think that any QRM from "out of band" would
> have to be from really strong signals causing IMD in the front end,
> before the IF filters, and that IF filters could not help this.
>
> DE N6KB
>
>
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