[CQ-Contest] Dayton PileUp Winner

[doug smith]

On 5/19/08, Pete Smith <n4zr at contesting.com> wrote:
> Judging by the scores this year, the 2008 tape may have been a lot
> tougher.  I wonder whether anyone made an effort to note callsigns that,
> for whatever reason, were decoded correctly but only once.

I would say it was tougher.  The top score this time was 52 (vs. 71 in
1999) and the other high scores were in the upper 40s and up to 50.
Of course I don't recall the rest of the top-10 scores from 1999 but
I'm sure they were all in the upper 60s through 70.  If I recall
properly the method used for generating the tape has changed since
1999.   (can someone from KCDXC address that?)

I recall few if any calls that were only sent once, but quite a few
where one of the transmissions is at least partially buried in QRM.
Then again, Skimmer shouldn't be fazed by that?  There was one call
that had LOTS of drift, it was plenty loud & easy to copy by ear but
from your description of the algorithm it sounds like Skimmer would
have missed it.  I don't recall any other drifting calls this year.
Some years the tape includes calls with considerable chirp, wonder
what that would do to Skimmer?

Compared to 1999, the Skimmer did worse with this year's tape, but so
did the humans.  The Skimmer's results as a proportion of the best
human score was better this year - it got 60% of the calls I got, vs.
51% on the 1999 tape.

Pete, do you have a handle on how far apart (in frequency) signals
must be for Skimmer to discriminate among them?

==
Doug Smith W9WI
Pleasant View, TN  EM66
http://www.w9wi.com

(I did download Skimmer Saturday night and will be playing with it
this week, if my PC is fast enough!)