[RTTY] 200 hz filter on RTTY

[Tom Osborne]

I use 250, with an Inrad filter, all the time for RTTY.  Any wider than that 
is too wide for me.  Not sure about narrower as I can't get less than 250 
cycles here.  The number 2 radio here has a 500 cycle filter and that is WAY 
too wide. for contesting. 73
Tom W7WHY


Don, AA5AU, wrote:
> I think I remember someone, maybe Chen, saying a 200 Hz
> filter would not work on RTTY or something to that effect.
> Maybe I don't have the story just right, but it appears to be
> working great.  Too tight for contesting, but works when required.

A passband narrower than about 280 Hz removes some of a 45 baud signal.
OTOH, I have used a 200 Hz DSP filter a lot in contests and pileups because
removing off-frequency signals is a bigger benefit than the little bit lost
with the too-narrow filter.  This requires precise tuning but helps separate
signals.  Even 150 Hz works pretty good, though I never go that narrow.

73,
Ed
--------------
Ed Muns - W0YK
www.w0yk.com

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