Hi Dennis
The is a another consideration for digital modes if you are planning to
work RTTY as well as other digital modes. In setting up my K2 a long
time ago, I found much better results with narrow filtering could be
achieved by using an audio frequency pair (mark and space tones) lower
than the 2125-2295 standard suggested for most RTTY work. Using MMTTY,
I chose 915 for the mark frequency mark, although using 1275 or 1445
should be fine. With the high tones I was not able to get flat band
pass shaping that was similar between the 15 meter-and-up and the 20
meters-and-down conversion arrangements that the K2 has. Some will
warn you not to use low tones because of opposite sideband leak, but I
have never had that problem, even when checking with a second RX in the
shack. I aligned my narrowest filter as low as 40 hz (nominally- it's
actually much wider than that) and it worked well in crowded RTTY
contest conditions. I ended up with nominal filter widths of 40, 75 and
135 hz. For working PSK and JT65 and 9 you will probably want another
filter set up as wide as possible.
73, Dave, K2YG
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
