Using AR Cluster Spot Filters

Bill, K1GQ, February 2018

When you connect to a DX Cluster node running version 6 of the AR Cluster software, you receive DX announcements, termed spots, from all around the world. If you do this, you should choose the Assisted item for the Assisted: choice in the Cabrillo Category Items box in your settings opened by Log ► Cabrillo Settings….

During a contest, there can be millions of spots per day. SkookumLogger converts received spots into activities and displays them in Activity tables for each band. The conversion eliminates some of the spots, but that processing can interfere with other concurrent processing by SkookumLogger so it is better to eliminate spots before they are sent to you. You do this by defining a spot filter. Spot filters are stored on the node that you are connected to, and reduce the number of spots that are sent to you without affecting anyone else. Each node has a possibly different spot filter associated your login call.

You can use SkookumLogger to define a spot filter, in the DX Cluster preferences panel. The challenge is understanding what to enter there. While the Help ► AR Cluster Spot Filter Guide menu item opens a web page containing the documentation for spot filter syntax, that syntax is unfamiliar to those without a computer science or mathematics background. Also, some of the terms in the documentation are ill-defined. This note attempts to elaborate on that latter point.

For CW mode, skimmers generate nearly all of the spots. These flags affect spots generated by skimmers:

Lacking a reliable SkimDupe flag, consider adding a filter clause that passes only spots from skimmers near you. For example:

AND (SpotterItuZone = [4,8,9])