I have a 250 Hz filter I use for PSK and RTTY. It helps when
there is a strong nearby station that overloads the AtoD
converter between the K3 and my computer. During a RTTY contest,
I found it helped, but the dual frequency DSP RTTY filter was
more than enough for most contacts.
When I use the filter with PSK, I lose the computer waterfall
and the computer noise reduction because of the narrow
bandwidth. I use full bandwidth to scan for signals and the 250
filter after establishing contact. Usually a narrow filter works
better than the computer noise reduction.
I would worry about 200 Hz for RTTY. While the deviation is
nominally 170 Hz, there is energy out wider than that which may
be affected by the skirts of the 200 Hz filter.
IMHO, RTTY is like AM -- a classic mode which uses more
bandwidth than necessary, but is nice to keep around for
nostalgia and to relive history.
Cheers - Bill, AE6JV
On 11/27/13 at 9:58 AM, [email protected] (Dave Barr) wrote:
Which two of the 200/250/400 and 500 hz filters are best for
digital use, primarily RTTY, both contests and dx. I
understand that for JT-65 and PSK the standard ssb filter, or
even the AM filter is useable. I am concerned that the 200 hz
might be too narrow for RTTY. I work some CW but almost no ssb.
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