[Skimmertalk] Bad Skimmer Spots

Fri Feb 4 09:46:57 PST 2011

There is a beginning of the user manual at:
http://www.ab5k.net/ArcDocsVer6/UserManual/ArcDx.htm, this doesn't have the
description of the unique or master.dta filter yet.
And there is a user application that lets you set up the filters
graphically. 

David Robbins K1TTT
e-mail: mailto:k1ttt at arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net

> -----Original Message-----
> From: Igor Sokolov [mailto:ua9cdc at gmail.com] 
> Sent: Friday, February 04, 2011 17:36
> To: K1TTT; n4zr at contesting.com
> Cc: Skimmertalk at contesting.com
> Subject: Re: [Skimmertalk] Bad Skimmer Spots
> 
> 
> David, I am not aquainted with arc-6 but what you describe is 
> pretty close 
> to what I need.  I need to be able to choose either cluster spots or 
> skimmer spots or both. Preferably with separate filtering for 
> each of the 
> two. For skimmer spots I need additional filtering based on 
> the number of 
> skimmers generating spots for the same call (choose 2, 3 or 
> even 4) plus 
> filtering based on master.dta. Having been able to choose all 
> these filters 
> in any combination would be ideal.
> CC client has a very good user interface which allow user not 
> to remember 
> all those filtering commands required by cluster software. 
> Adding filtering 
> described above to CC software using the same easy user 
> interface would be a 
> great advantage.
> 
> 73, Igor UA9CDC
> ----- Original Message ----- 
> From: "K1TTT" <K1TTT at ARRL.NET>
> To: <n4zr at contesting.com>; "'Igor Sokolov'" <ua9cdc at gmail.com>
> Cc: <Skimmertalk at contesting.com>
> Sent: Friday, February 04, 2011 7:11 PM
> Subject: RE: [Skimmertalk] Bad Skimmer Spots
> 
> 
> > That is why arc-6 is passing all the rbn spots on to the 
> client, so duping
> > and filtering can be done by the user.  You might also want 
> to check out
> > some of the new filters, in the latest beta update there is 
> a number of
> > times spotted filter, so you can limit the rbn spots you 
> see to ones that
> > have been spotted 2 or more times, and there is also a 
> master.dta filter 
> > to
> > only see spots in the supercheck database... Those filters 
> can be combined
> > in statements like:
> >
> > not skimmer or (skimmer and unique > 2) or (skimmer and master)
> >
> > Which would give you all non-skimmer spots, plus skimmer 
> spots that are
> > spotted more than twice on the same band within 10 minutes, 
> plus skimmer
> > spots that are in the master.dta file regardless of how 
> many times they 
> > are
> > spotted.
> >
> >
> > David Robbins K1TTT
> > e-mail: mailto:k1ttt at arrl.net
> > web: http://www.k1ttt.net
> > AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
> >
> >
> >> -----Original Message-----
> >> From: Pete Smith [mailto:n4zr at contesting.com]
> >> Sent: Friday, February 04, 2011 13:38
> >> To: Igor Sokolov
> >> Cc: Skimmertalk at contesting.com
> >> Subject: Re: [Skimmertalk] Bad Skimmer Spots
> >>
> >>
> >> There is a third possibility, but the problem is a little
> >> trickier than
> >> I had thought.  Here's an excerpt I just sent to someone on
> >> another list:
> >>
> >> "As for the theoretical error rate, let's take an example.
> >> Say you have
> >> N6NC CQing for an hour and being heard by 10 RBN Skimmers.
> >> Each Skimmer
> >> will spot you correctly 5-6 times (every 10-12 minutes).  
> But if some
> >> local event - transmitter splatter, QRN, QRM (especially 
> things like
> >> clicks from a loud adjacent station) causes a mis-spot, then
> >> whichever
> >> Skimmer that mis-spotted you will immediately send out a bad spot.
> >>
> >> Say just one of the Skimmers listening to you sends one bad
> >> spot of you
> >> in that hour. That's 1 bad spot.  Meanwhile, the good 
> spots are being
> >> filtered out as dupes by client software, so that clients are only
> >> receiving 5-6 good spots of you.  Holy cow, that's a 16-20 percent
> >> apparent error rate.
> >>
> >> It's the aggregation, which is why the RBN has to come up with a
> >> solution.  This is a fairly tricky problem, because the 
> system has a
> >> built-in preference for new spots, whether good or bad.  The
> >> bad spots
> >> can come at any time when you are CQing.  Meanwhile, the good
> >> spots will
> >> tend to cluster, because most people who spotted you
> >> correctly will have
> >> done so within a few seconds of your first CQ, and then at
> >> 10-12 minute
> >> intervals thereafter.  I don't know just how this one will 
> be solved,
> >> but I think it can be.  The devil, as usual...
> >>
> >> 73, Pete N4ZR
> >>
> >> The World Contest Station Database, updated daily at
> >> www.conteststations.com
> >> The Reverse Beacon Network at http://reversebeacon.net, blog
> >> at reversebeacon.blogspot.com,
> >> spots at telnet.reversebeacon.net, port 7000
> >>
> >>
> >>
> >> On 2/3/2011 11:38 PM, Igor Sokolov wrote:
> >> > Lee, I think it would be excellent if VE7CC client software
> >> could have
> >> > filtering and validation facilities. There were so many
> >> broken spots during
> >> > CQWW 160 that filled the entire band map and their
> >> percentage was reaching
> >> > 80% on the last night of the contest.
> >> > I see two methods of validating spots:
> >> >   1) pass the spot if the call has been mentioned by 2 or 3
> >> other skimmers
> >> > 2) Pass the spot if it is in the master. dat file.
> >> > Combination of these two would probably cut the number of
> >> broken spots to
> >> > acceptable figures.
> >> > I think telnet client software is the best place for
> >> filtering (better then
> >> > filter in the logger or at the skimmer)
> >> >
> >> > 73, Igor UA9CDC
> >> > ----- Original Message -----
> >> > From: "Lee Sawkins"<ve7cc at shaw.ca>
> >> > To:<Skimmertalk at contesting.com>
> >> > Sent: Friday, February 04, 2011 3:12 AM
> >> > Subject: [Skimmertalk] Bad Skimmer Spots
> >> >
> >> >
> >> >> Here is a small subset of bad skimmer spots. I am looking
> >> at a full feed
> >> >> from the RBN.
> >> >>
> >> >> These are only spots for USA calls that have not been
> >> issued.  Many times
> >> >> the first letter of a call is missing.  Many of these are
> >> actually Italian
> >> >> calls with the "I" missing.
> >> >>
> >> >> http://www.bcdxc.org/ve7cc/notissue.txt
> >> >>
> >> >> I will update the list from time to time.
> >> >>
> >> >> CC Clusters drop these bad calls.
> >> >>
> >> >> There are many other non USA calls that are wrong which
> >> also have the
> >> >> first
> >> >> letter missing. These are harder to find.
> >> >>
> >> >> Other bad calls occur when the last letter is missing or
> >> truncated or is
> >> >> added
> >> >> +in error.
> >> >>
> >> >> "E" and "T" seem to be the most often added bad letters.
> >> >>
> >> >> Lee
> >> >> _______________________________________________
> >> >> Skimmertalk mailing list
> >> >> Skimmertalk at contesting.com
> >> >> http://dayton.contesting.com/mailman/listinfo/skimmertalk
> >> > _______________________________________________
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> >> >
> >> >
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> >>
> >
> > 
> 
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