[RTTY] Bandwidth of a RTTY signal

[Doug Faunt N6TQS +1-510-655-8604]

To diverge wildly here

   From: "Michael C. Joens" <michael@joens.org>
   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