[1000mp] cw fiters

Sat, 1 Nov 2003 11:32:51 -0700

Don't forget one more advantage to having a matched pair of filter
bandwidths--one in each IF.  The WIDTH control work much more effectively.
This is because you have coincident edges of the two filters to shave off
either side of the input spectrum when you move the WIDTH control.  If you
have a 400 Hz. filter in one IF, and a 2.4 KHz. filter in the other IF, then
the WIDTH function doesn't work so well.  So under heavy QRM, a matched pair
of steep filters is hard to beat.

If you don't use WIDTH, it isn't quite so important.  All you are doing is
getting steeper skirts with a pair of filters.  But the WIDTH is a pretty
effective tool, so for me it's worth it to have a matched pair.

Having said that, I have an "almost" matched pair (400Hz Inrad and 500Hz
stock), plus a pair of 250Hz. Inrads.  I like the combination.

73,
Tom / W7GT

----- Original Message ----- 
From: <[email protected]>
To: <[email protected]>
Sent: Saturday, November 01, 2003 10:48 AM
Subject: Re: [1000mp] cw fiters

> Hello John,
>
> IF-filters in cascade give you more selectivity.
>
> This will be very effective during difficult circumstances, like contests
> and crowded bands.
>
> 73, Hans Remeeus.
> Ham Radio: PA1HR
> www.remeeus.nl
>
> Communication is about people, the rest is technology.
>
>
> ----- Original Message -----
> From: "n3drk" <[email protected]>
> To: <[email protected]>
> Sent: Saturday, November 01, 2003 6:40 PM
> Subject: Re: [1000mp] cw fiters
>
>
> > Neal,
> >      I dont understand something. Why do you have the 500hz filters back
> to
> > back. Is it not sufficient to just have one 500 in the 2nd if? What
effect
> > does having another 500 in the 3rd if have?
> > thanks
> > john
>
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