[Icom] FL-80 versus FL-103 filters

[Adam Farson]

Hi Dana,

Many thanks for posting the filter data. I have added a "Shape Factor"
column to the filter list on the Icom FAQ site.

http://www.qsl.net/icom/filters.html

Cheers for now, 73,
Adam VA7OJ/AB4OJ

-----Original Message-----
From: icom-admin@mailman.qth.net [mailto:icom-admin@mailman.qth.net]On
Behalf Of Dana Hoggatt
Sent: Tuesday, December 03, 2002 07:43
To: icom@mailman.qth.net
Subject: Re: [Icom] FL-80 versus FL-103 filters


On Dec 2,  4:59pm, "David Hammond" wrote:
} Subject: [Icom] FL-80 versus FL-103 filters
} From: "David Hammond" <dhhdeh@concentric.net>
}
} I am thinking about substituting the FL-80 in my newly
} acquired IC775DSP with either an FL-70 or FL-103. Both
} are SSB filters at 2.8 kHz bandwidth at the 9 MHz IF
} frequency  (9.0115 MHz)
}
} Can anyone enlighten me as to the differences in
} mechanical or electrical specifications on these filters?
}
} I may be swapping the FL-80 along with an INRAD #109
} into the narrow SSB positions.


It isn't much, but here's what I have:

     Filter        Bandwidth      Shape Factor
     -------------------------------------------
     FL-80           2,600            1.5
     FL-70           2,800            1.8
     FL-103          2,800            1.8
     FL-223          1,900            1.9

The FL-80 is a GOOD filter.  Are you sure you want to
widen your passband like this?  Most people are usually
trying to narrow their passbands.

If you're really planning to widen up your 9Mhz IF like
this, don't forget to do the same with your 455Khz IF.
Otherwise, you might not get the results you expect.

The Inrad 109 is an excellent filter, equal or better
than the Icom FL-44/A, another great filter.  Both will
match up with the FL-80 nicely.  However, most people
would not consider any of them to be "narrow" filters.
Typical "narrow" filters are: FL-222, FL-223, Inrad
314, Inrad 322, etc...