[TenTec] Orion Roofing Filter Cut In

[Bob Henderson]

Sinisa

You are correct, I am mistaken.  Which, I guess, brings us back to the
original question about whether switching roofing filters at DSP b/w = 75%
roofing b/w is optimum or unecessarily conservative?

Bob, 5B4AGN


----- Original Message ----- 
From: "Sinisa Hristov" <shristov at ptt.yu>
To: <tentec at contesting.com>
Sent: Friday, August 06, 2004 7:53 AM
Subject: Re: [TenTec] Orion Roofing Filter Cut In


> Bob Henderson wrote:
>
> > Well...........the one thing that everyone appears to be overlooking
here is
> > PBT.  If the 2400 Hz roofing filter were to switch in at 2400 Hz DSP
then
> > the PBT control would not function.  Instead of adjusting the position
of
> > the passband relative to carrier it would merely be effective as a b/w
> > reduction control and Orion already has one of those.
>
> Not true.
> It is easy to verify that PBT functions correctly
> with both filters at 2400 Hz, or any other value.
>
>
> > I imagine Ten Tec have used DSP b/w = 75% roof b/w to maintain a
reasonable
> > PBT range at all DSP bandwidths.
>
> No, Orion normally uses only the central part of roofing filter's BW
> in order to prevent deterioration of DSP filter's flatness in the
passband.
>
>
> 73,
>
> Sinisa  YT1NT, VA3TTN
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