Tuesday, December 24, 2013

A New Tutorial on Using the RBN

It has been over three years since I last wrote a tutorial for users of RBN spots, and I was amazed when I read the old one to discover how much things had changed.  Here's the current word.

There are two RBN Telnet servers, at telnet.reversebeacon.net port 7000 and arcluster.reversebeacon.net, port 7000.  The intended use of these servers, however, is not to provide spots to end users, but rather to feed spots to AR Cluster and CC Cluster nodes worldwide for "retail" distribution.

To find a cluster node that provides what you want, go to and search by software type. Of course, geography is pretty unimportant these days, with the demise of RF clusters, but you'll want to check to be sure the node you use has Skimmer spots from the RBN as well as the filtering capabilities you want.
 
Both ARCluster Version 6 and CC Cluster provide a choice to users as to whether to include spots from the RBN in the spots they receive.  More importantly, each has its own set of filtering capabilities, with quite different underlying philosophies.  Why filter? Because even on a Monday morning, the RBN typically pumps out more than 120 spots per minute, and during a contest, the flow can be 20 per second average.

If you use a VE7CC (CC Cluster) node, he has already made some decisions for you.  His nodes provide de-duped data, which all by itself will cut the volume of spots by more than 80 percent, and he has done some pre-processing to reduce busted spots.

A complete list of CC Cluster commands is at http://bcdxc.org/ve7cc/ccc/CCC_Commands.htm. The easiest way to set filters is to use the very versatile CC User client program, available from http://www.bcdxc.org/ve7cc/default.htm#prog



state province

Among other useful features, CC User can be used between a cluster node and a logging program, to make it easy for you to manage your filters.

A caution - CC User is usable with DX Spider, CC and AR Cluster version 4 nodes.  It is not compatible with AR Cluster Version 6, which has adopted an entirely new  "Boolean" filter syntax.

The AR Cluster commands are at http://ab5k.net/ArcDocsVer6/UserManual/ArcCmdSummary.htm.  As you can see, the default AR Cluster posture is not to remove duplicate spots.  This offers one important benefit - to use a program such as Viewprop, which relies on spots to and from your area to give you a near-real-time portrayal of propagation, you must have access to all spots of each station.

AR Cluster also has a client program, available at AB5K's web site.  It provides for setting a wide variety of user-defined filters, including duplicate removal if you wish



A feature not found in CC Cluster is the inclusion of CT1BOH's "skimquality" algorithms, which flag verified spots (ones heard by more than 2 Skimmers), QSYing stations (which may occasionally be image spots), and busted spots (based on a complex statistical algorithm.  Here's a sample of the output:





 
Note the spot of OK7FL as K7FL, about 3/4 of the way down - the algorithm not only identifies the spot as a likely bust, but also tells you what the correct call is.  You can filter on any combination of these attributes - for example, so that you do not see busted spots, or QSY spots until they are verified by at least 3 Skimmers.

A beauty of the AR Cluster filtering approach is that you can create compound filter selections to store very complex filtering combinations as a single string.  for example, the Hi-Q button on my N1MM Logger Telnet window above, when clicked, tells the cluster "SET DX FILTER call=n4zr OR (NOT Skimbusted and spotterstate=[MD,PA,VA,NJ,WV, NY,NJ,NC]).  This lets through any spots of my station from anywhere in the world, and lets through both Skimmer and traditional spots from the states listed, deleting any that the cluster believes to be busted.  Here's a sample with the filter in use:



Note that since I did not choose to block the first spot of a new station or a previously-spotted station on a new frequency, spots coded ? and Q come through immediately. 

That's about the whole story.  I hope this encourages more people to use Skimmer/RBN spots for CW, RTTY and BPSK.

73, Pete N4ZR

3 comments:

  1. Hi for all, do you know if exist any client for Linux Operating system???? i´m only find windows based software for RBN, and Clusters... Thanks in advance.
    Mati LU9CBL

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    1. Hi Mat - There are a number of Linux logging programs that incorporate Telnet for DX cluster connection. Any of these will work. All of the filtering discussed in the tutorial will work with any Telnet client, because the filters are set at the cluster node, not in the client. You might look at http://www.dxzone.com/catalog/Software/Linux/. I think there is also a similar site in Australia with some good ideas.

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