[CQ-Contest] Ingenious prefixes and the RBN

[N4ZR]

This may be old news to many of us, but VE3NEA's CW Skimmer Server 
determines how "skeptical" to be about a callsign, based on a file of 
all expected callsign patterns. This assessment in turn affects how many 
repetitions of a callsign it must "hear" before issuing a spot.

>From time to time, this causes problems for contesters who have gone out 
of their way to get a truly unique callsign for use in contests like 
CQWPX.  For example, normal Belize callsigns are V31@@ (where @ is an 
alphabetic wild card), but I have recently been told about the issuance 
of a V3@ callsign for contest use.

Revising the callsign pattern file in a truly systematic way involves 
getting data from QRZ.COMon the number of "hits" for each callsign and 
massaging the data with exotic techniques (exotic to me, anyway) to turn 
callsigns into patterns and aggregate the numbers of hits to determine 
how common the pattern is.  It's a lot of work.

With a little time remaining before CQWPXCW, I'm offering an interim 
fix.  If you have received what you believe to be a unique prefix and 
have not used it before March, 2017 (the last systematic overhaul of the 
pattern file) e-mail me by May 1 and I will incorporate the new pattern 
in the RBN's pattern file distribution, which will be made available to 
all RBN nodes by May 10.  I can't promise you that all node-ops will 
download the new file before the contest, but the server will at least 
"nag" them to do so.


73, Pete N4ZR