It's sort of the perfect example of "your mileage may vary. I like the
narrowest filter. Even moreso, I use an outboard DSP filter that also has
bandpass capability and I like to crank that down also. Of course, the IF
filters being far upstream are essential for many reasons.
Additionally, when doing PSK or RTTY I like to crank the DSP filter down
(not so narrow of course for these modes, especially RTTY). It seems to
help a lot with decoding and also separating extremely close signals.
73 de Gary, AA2IZ
----- Original Message -----
From: "Ken Brown" <ken.d.brown@hawaiiantel.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Sunday, October 21, 2007 6:35 PM
Subject: [TenTec] Purpose of 250 Hz 8 pole filters
>
> > Another viewpoint: I have both filters (500 and 250) in my Corsair
> > II, and found that I never used the 250. Too narrow for comfortable
> > tuning, and if I couldn't isolate a signal in the 500 hz bandpass it
> > wasn't worth the aggravation anyway.
> >
> >
> This is sort of my experience too. I do use the model 221 six pole 250
> Hz filter in the 9 MHz IF a lot. However the model 282 in the 6.3 MHz
> IF never gets used . Using the 250 Hz 8 pole filter "interferes" with,
> or detracts from, my own ability to discriminate between
> noise and CW signals. I found I was also not using the 250 Hz filter in
> a FT-1000 this weekend for the same reason. It seems like the main
> purpose of a 250 Hz 8 pole filter is to use it to demonstrate that you
> don't really need a filter narrower than 500 Hz. This is for human
> copied CW, there may be practical application of the 250 Hz filter for
> other modes.
>
> DE N6KB
>
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>
>
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