I've been a ham for almost 50 years, but I never operated RTTY until
about two weeks ago. It was an award offered by the Chinese for working
their special event stations for the Beijing Olympics that was the catalyst.
I'm using a KAM connected to an FT-1000MP Mk.V and the WinWarbler
program from the DX Lab Suite. I'm using 500Hz filters, and using the
shift and width controls to narrow the passband from there. My 250Hz
filters seem to be too narrow and I'm not sure why that is. The biggest
problem I'm having is tuning in weak signals and copying through QRM.
I have a couple of books on RTTY dating back to the 1960's. They talk
about using TU's that can decode with only the mark or only the space
signal. This seems pretty straightforward, since the mark and space
together provide 100% redundancy. I haven't figured out how to do that
with what I'm running, and on weaker signals I'm finding a tuning error
of only 10Hz can make the difference between copy and no copy.
What do I need to do better? Are there any good recent books on RTTY? I
have the ARRL HF Digital Handbook, but it only covers the basics. Thanks!
73,
John, K9MM
_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty
|