> Hi Joel;
> Generally, selectivity at a high IF tends to improve the nearby stong signal
> rejection characteristics of the receiver, but close-in skirt selectivity of
> high IF filters is usually not as good as low IF filters. So, the best is to
> have both filters. If you can only afford one filter, in my opinion, it
> should be the high IF filter. The best system uses good skirt selectivity
> filters in both IF's. This is why International Radio filters are used by
> serious contesters.
73, Fred
> Message: 4
> From: "Joel N. Weber II" <kb1grs-vhfcontesting@vms.gratuitous.org>
> To: vhfcontesting@contesting.com
To: <vhfcontesting@contesting.com>
> Date: Sun, 16 Jun 2002 20:22:52 -0400
> Subject: [VHFcontesting] IF filter selection
>
> The club I'm involved in (w1xm) is looking into adding filters to our
> IC-746, which has never had any of the optional filters installed. It
> has been the rig we use for 6m in the VHF contests, and we also have
> used it for HF for Field Day. We do primarily SSB operation, as most
> members of the club aren't terribly proficient at CW operation, but
> there is one operator who frequently does CW, so we want to have
> filtering that is suitable for both modes.
>
> Which filters would be best to install? I understand that the rig
> will take up to three optional filters, some of which have a 455 khz
> center frequency, and some which have a center frequency somewhere
> around 9 mhz. I don't think I've ever come across much literature
> that explains in much detail why one would prefer one center frequency
> over the other, nor am I terribly clear on which bandwidths are best
> for SSB use.
>
> So I'm curious if the people on this list have thoughts on which
> filters would be the best to get, and why.
>
> (Another possibility that has been suggested is that perhaps replacing
> that rig with an FT-920 (or perhaps some other rig) would be
> worthwhile.)
>
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