That's interesting - the 6.3 MHz 2nd IF 250 Hz filter is a legend for its
ability to eliminate noise and provide better S/N ratio than others. That
was my and many others' experience on the Omni VI/VI+ several years ago. It
was so good, that I purchased (but have not yet installed) the same filter
for my Orion. I found if I cascaded it with the 500 Hz filter in the 1st
IF, it was just amazing.
73, Duane
Duane Calvin, AC5AA
Austin, Texas
www.ac5aa.com
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
On Behalf Of Ken Brown
Sent: Sunday, October 21, 2007 5:36 PM
To: Discussion of Ten-Tec Equipment
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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