Monday, February 13, 2012

Making Best Use of The RBN in the ARRL DX Contest

If you're not planning to operate Assisted or Multi-op in this weekend's 
contest, you can skip this now.  Otherwise, let me offer a few thoughts that 
may help you make best use of Skimmer spots from the Reverse Beacon Network.

1.  Use a node that allows you to include or exclude Skimmer spots with 
a simple command.  Both ARClusterV6 and VE7CC Cluster nodes have this 
capability.  Some logging programs and Telnet clients may also have this 
capability built in

2.  If you use the RBN and your logging software lets you set a packet 
time-out value, set it for no longer than 10 minutes.  The skimmer 
software automatically re-spots stations that continue CQing on the same 
frequency only once every 10 minutes, but typically such re-spots appear 
within a few seconds of the 10-minute threshold, since we now have 
pretty wide coverage.  You'll cut down on the number of "stale" spots 
this way.

3.  By all means *do* use filtering of some sort to limit the number of 
Skimmer spots you receive.  The major contest software packages can all 
handle the load, but except in very special circumstances you'll want to 
filter.  For example, if you filter by geographic origin of spots, you 
can pretty much assure yourself that you'll be able to hear everything 
that is spotted.  ARCluster version 6 also has the ability to set a 
threshold and not pass you a spot until at least "x" Skimmers worldwide 
have concurred.  This can materially help you to reduce busted spots.

4.  Be skeptical of spots that appear on your bandmap on the very same 
frequency as someone who has already been spotted there.  Despite all 
the care VE3NEA has taken to prevent it, stations that call more than 
once, very close to the running station's frequency and CW speed, may be 
mistaken for runners and spotted by a Skimmer.  As you can imagine, this 
may be particularly common on the low bands.

See you in the pileups!

73, Pete N4ZR


  1. Hi, Pete - I had mostly very positive experiences using the RBN in ARRL CW. I use VE7CC's software to only pass skimmer spots from W3, VA and WV and that works great.

    There did seem to be an outage on Saturday afternoon or late morning. The RBN just died, could not reconnect. Switched the LPL cluster for a while, checked the RBN a few times, still down. Outage seemed to last a few hours.

    On Sunday, the busted spot problem seemed reduced compared to previous contests but still there. Missing started dits (like B1A instead IB1A, and a few others) and some trailing dits (like the short HG#X type calls) seemed most common.

    EA9EU seemed to be a mystery RBN spot all weekend. I jumped on it from the RBN several times, never once actually heard hime there. Could be some skimmer spamming, not sure what was going.

    Those issues represent less than 1% of my use of the RBN for an assisted entry. AS a small station, I can use SO2V with my K3 and generally use the RBN to maintain S&P rates about equal to and often higher than what I can get running - and never have to send QRL!!

    73, John K3TN

  2. Thanks, John. Yes, the DXSpider node went down, but Dave, KM3T did a repair and got it back up fairly quickly. As far as I know the ARC6 node kept running throughout.