Tuesday, January 28, 2014

Want to Spot Beacons? Here's How

Note - new information below in bold, since this was initially posted.

 From time to time, people ask me how to spot more beacons, or why RBN nodes don't spot more.

For many beacons, the question has a trite answer - because the nodes aren't covering and decoding the frequencies where the beacons are.  The question is "why?", and the answer lies in the SkimServ.ini file used by the Skimmer Server software, and in your Skimmer Server settings. The NCDXF beacons are a special case, and we'll deal with that a bit later.

First, the easy ones.  Open Skimmer Server, and select the Telnet tab.  Make sure that the box "Send only CQ Spots" is unchecked.  Unless you do this, you'll never send any beacon spots.  Set the Validation level to "Normal", because the beacons may not be sending the keywords or the optimum number of repeats of their callsigns needed to be recognized by CW Skimmer.

Now let's fix the .ini file.  The first small challenge is to find the file.  In Windows XP, it is typically installed in the Afreet folder under Program Files.  In Windows 7 and beyond, you'll most likely find it in C:\Users\[your logon name]\AppData\Roaming\Afreet.

Once you track it down. open it and you'll see this group of lines:

21022750, 21068250,24912750,28022750,28068250,50022750,50068250,50113750,50159250
28045500, 28136500,50045500,50136500

The first three rows are center frequencies for each of the three possible bandwidths.  You'll note that the actual bandwidth covered by each is slightly less than its name would suggest - for example, 192 KHz actually covers 91 KHz below and 91 KHz above the center frequency, not 96.  With many of the beacons you want to spot 100 and more KHz above the lower band edge, you'll want to run 192 KHz bandwidth to be sure to find them - on 10 meters, some are even above 28.182, so you may want to define a second 10-meter segment to allow your QS1R to listen higher.

The next magic trick is in the line titled "CWSegments."  This is something that Alex added in order to conserve computer power by not decoding a lot of junk, like RTTY, PSK31, etc.  Fortunately, the way Alex implemented it is quite flexible.  You can add segments at will, simply by adhering to the format, which uses frequencies to the nearest Hz, and separating them with a comma  For example, if you want to capture the NCDXF beacon frequency on 20 meters, you'll want to add a CW Segment of 14095000-14105000.  To avoid all the RTTY activity on 20 meters, you might want to split the 20M segment in two - 14000000-14070000,14095000-14105000.

Incidentally, if you like to make as many contest spots as possible, you may also want to modify this line, because during CW contests people frequently operate up into and well beyond the RTTY/PSK segment.  The cost of opening it up, of course, is that if the RTTY guys stick it out during the CW contest, you'll get some of the "EE5EEE" type of junk spots.

The NCDXF beacons are a special case, because they only sign their callsigns once before they begin their power step-downs, and then the next beacon takes over.  As a result, CW Skimmer and Skimmer Server often don't hear enough repetitions to validate and spot a callsign.  

CW Skimmer has a special function called a Watch List, which is discussed in the Help file.  Put the beacon callsigns on the list, and they will be spotted the first time they are heard. Unfortunately, there is no Watch List in Skimmer Server.  Alex says that there is an update in the works, and hopefully this capability will be added.  Stay tuned.

So that's the story to date.  Let me know if you find this useful.

73, Pete N4ZR

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