To diverge wildly here
From: "Michael C. Joens" <michael@joens.org>
To: <rtty@contesting.com>
Date: Tue, 28 Aug 2001 23:52:51 -0400
The IC-756PRO is a totally different matter, though. Here, if a filter says
it's 250Hz, that's all you get. No slopes (to speak of). The PRO's RTTY
filter is 350Hz wide, matching the theoretical 316Hz quite well. Icom
actually took it a step further and implemented a twin-peak filter. This is
as close to perfect as I've seen. The PRO's RTTY filter carves out mark and
space with their narrow bandwidth and suppresses the unused spectrum in
between. Note that the twin-peak filter of the PRO is only available in FSK
mode. If you use AFSK, you're limited to the standard filters, which should
be set to about 320 to 350 Hz wide. If you go any narrower than 320Hz, you
The ICOM mailing list has been passing around information about the
756PRO-MKII version, which apparently allows AFSK with the twin
bandpass filter. I am a big believer in the PRO filters.
73, doug
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