[CQ-Contest] Skimmer and the cluster network - was: Skimmer - Proposal & Compromise

Pete Smith n4zr at contesting.com
Fri Jun 6 06:45:18 EDT 2008

At 06:06 PM 6/5/2008, David Robbins K1TTT wrote:
>The purpose of the
>cluster network is to find stations that are cq'ing.  A 'reverse beacon
>network' that listed all the stations it could hear would be good only for
>propagation studies in my opinion, something I would like to see once we get
>the bad spot rate down.

By design, the reverse beacon network that is currently operating 
(http://skimmer.dxwatch.com) only posts CQers.  This choice was made 
because of concern that the volume of spots would be overwhelming, yet even 
with this limitation (and discounting the obvious miscopies) the number of 
Skimmer spots exceeds the number of human spots on the worldwide network by 
at least 10:1;  There are two main reasons for this:

*  Most important, Skimmer posts every CQ'er it can copy, not just those 
that a human operator somewhere deemed interesting.  That alone makes 
Skimmer spots on a network more of an annoyance than a benefit for DXers, 
but it can make a local Skimmer invaluable for a contester looking for new 
stations to work on Sunday.

*  Skimmer also reposts a station any time that station changes frequency, 
and every 10 minutes if it remains on the same frequency.  This capability 
makes it great for DXers trying to be first to elusive DX, but means more 
spots that repeat themselves.  Again, not great on a network, but fine for 
feeding spots to a local contest logger.

You can expect a significant improvement in callsign verification with the 
next version of Skimmer, which Alex is finishing up now - I have been doing 
alpha and beta testing for the last month.  It has four selectable levels 
of verification, using tools such as the latest master.dta file and a 
3-character callsign pattern file that is based on 11 years of cluster 
spots.  Depending on which you select, it applies different repetition 
criteria before "accepting" a callsign for posting. There is even a 
verification mode (working title "Paranoid") that *only* posts callsigns 
that are found in the master.dta file (or in a watch-list you can build 

73, Pete N4ZR

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