Introduction  AR-Cluster V6 User Manual

Version 6: 20 February 2012


Command Summary  

The command summary can be found at:  Command Summary   Start Here


What is a DX Cluster?

A DX Cluster is a network of connected amateur radio operators.  Users connect into a cluster, which generally serves a local region and clusters are linked together to form wider areas of coverage by geographical area such as state, country and even international level.  The result is a vast network of connected users sharing information pertaining to amateur radio.


Connections into a DX Clusters can be made using TNC/RF devices usually operating on VHF/UHF frequencies or Telnet using the Internet for connectivity.


Stations connecting into a cluster share amateur radio information including:

·         DX Spots

·         WWV Spots

·         Talk, Announcements, and Mail

·         Weather and Emergency Services


In addition DX Clusters offer general utilities for amateur operations such as:


·         Callsign Lookup Databases

·         QSL Databases

·         Great Circle Heading and Sunrise Sunset calculations



What is AR-Cluster?

AR-Cluster version 6 is a next-generation DX Cluster system that runs on the Windows platform.   We have been developing high performance contesting and DXing solutions since 1998.  


AR-Cluster features built-in Internet connectivity for connecting to other AR-Cluster nodes. 


AR-Cluster also features a brand new Clint tool for user connections.   The AR-Cluster Client application brings a whole new concept to cluster filters allowing filtering on the user’s desktop with simple visual filters that can be adjusted in real-time.    The client application also includes new docking features that allow the user to drag and dock various windows on his screen.   The following link shows a demo of AR-Cluster Client:


The client manual can be found at:


This manual is designed to help you become familiar with the AR-Cluster user commands that are available when you connect over telnet.  AR-Cluster nodes always sign with aarc>” at the end of an ID.


Want to setup your own DX-Cluster, check out the AR-Cluster web site at:


Telnet into AR-Cluster Ver.6 at:


View the quick commands/user manual at:  Quick Summary of Commands



What is AR-Cluster Version 6?

AR-Cluster version 6 is a next-generation DX Cluster system based on the latest .NET technology and a total re-write in the C# language.  It’s based on .Net and uses new technologies for enhanced performance.   It’s plenty fast enough to handle the new skimmer spots and has been tested to over one million DX spots per hour.  For the user AR-Cluster version 6 code offers the following improvements:


1.  Speed Improvements

The new technologies of multi-threading and in-memory databases make for a lightning fast cluster.   No more waiting for other user’s commands to execute before you command gets processed.  Using a multi-threaded language solves results in faster command execution.


2.  Expanded Filters

User and node filters have been vastly expanded.   All user filters are validated before being accepted into the system.  A new debug command allows for user debug and test of filters.  Users can now filter on any information in the DX spot.  A new continent filter was added extending spot filtering capabilities. A new “Debug” mode allows users to test filters.  There are also filters for specific contests.


3.   User Command Set

The user command set was developed featuring the new capabilities while offering better usability.  Many new commands have been added or expanded. The on-line help has been expanded. A new “Help on Error” feature is implemented automatically displays user help when a command cannot be executed. For example:  The incomplete command of “DX” or “Set/DX” will drive into the appropriate help section for the command.


4.  Telnet Server

A new multi-threaded telnet server has been developed and tested to 2000 plus users connections.


5.  Leverage Web Based Technology

We make use of newer .Net web based technologies. 


7.  Command Processor

The command processor operates on its own thread.  No more non-responsive GUI. 



Example:  Here is a example of the new debug command used to validate filter settings.  In this case the user filter is set to SpotterCont='NA'.  Spots passing the filter start with a "+" and spots that are rejected by the filter start with a "-".


+DX de AB3BK:    144195.0  N9LR         EN50>FN10 55                 W 0100Z PA

+DX de WX3B:       7094.0  OH0Z         QSX 7190.00 with new Antennas! 0100Z MD

-DX de EA3KU:      1826.9  OH2PJ        CQING DX                    OH 0100Z EA

+DX de WX3B:       7091.0  IW0HBY/IT9   QSX 7183.00                  I 0101Z MD

-DX de PY2SP:      7010.6  YU6AO        Strong!                     E6 0100Z PY

+DX de WX3B:       7084.0  4O6DX        QSX 7213.00 for W9's        E6 0104Z MD

-DX de EA3KU:      1828.4  UT8IO        CQING DX UT 0104Z EA


Selecting a Cluster

The key to selecting a cluster is performance.  With the addition of CW Skimmer spots and the Reverse Beacon Network the demands on the DX-Cluster system have increased by orders of magnitude.   Existing cluster software has demonstrated scalability issues and software authors have reduced features and/or imposed spot filters just so they can keep up.   The approach in AR-Cluster version 6 was to build a multi-threaded application from ground up that was optimized for the high spot volumes.   Users can get 100% of the raw spotting data or apply their own filters as needed.

DXers and contesters need to know their cluster application keep up with present day loads and scale to future spot volumes.

How fast is it?  You do the math, in AR-Cluster, performance metrics are calculated in real time and logged in the app log.   Here is a sample app log with execution timing, in seconds. Ex: [0.00081]].

It’s extremely fast. AR-Cluster has been tested at spot rates of over one million spots per hour and a CPU utilization of less than 20 percent.   AR-Cluster was chosen as a key cluster technology to run on the Reverse Beacon Network.  Additionally, AR-Cluster has also been used as the spot aggregator at the NC7J contest station for several years.


On-Line Help

On-Line help is available while connected into a DX-Cluster using the Help command.  The help command also displays command shortcuts.  Rather than typing full commands such as SHOW/WEATHER you can use the command shortcut such as SH/WE.  Also commands can be delimited by a slash, (“/”), or a space, (“ “) character.




help dx


help set/dx


AR-Cluster has new “Smart Help” logic so that any partial command will fall through into the help logic and display the help for the command.  If a user enters a mal-formed command as: "DX 14000" or "DX JA1AAA" or "DX" and the help for the DX command will be displayed.



dx 14000


Commands are listed in the full length command. If you do a help on a command, you will see the full length command and also its shortcut. The required part of the command is displayed in upper case and the optional part of the command in lower case.




Commands are organized into groups.  Type a command group for help on the subject. Help on any command shows the full command, a example and the shortcut for the command.    For help you can type Help/DX, Help DX, or just DX.  Most help commands have a "See Also" section that links to the parent command providing better help navigation and usability.


The major command groups are:











Telnet Connections

On a computer connected to the Internet, simply start a Telnet client session (go to a DOS prompt and type telnet) and open a connection to the IP address of the Cluster you are connecting to. 



telnet 23

You will see a login message similar to:

Welcome to the NC7J AR-Cluster cluster

Please enter your call:


Enter your callsign to complete the connection.




Logging out is done by issuing either the Bye or Quit command. If connected by Telnet, you can exit your Telnet client and automatically be disconnected.  If connected using packet, you can also use the TNC Disconnect command.


Keeping the Network Clean

AR-Cluster has advanced protocol for tracking questionable spots across the network.  Spots for DX, Announcement, TALK, WWV, and WX can be traced by sysops back to their source. If a user is telneting into a node, his Internet address will also be displayed. This capability has been very successful in tracking interference to the cluster network.




Helping the Network


If you use spots off the cluster network, then contribute by spotting back to the network. 



Supporting your Sysop


Setting up and operating a DX Cluster takes and lot of time and expense on the part of the sysop.  He has to maintain computers, radios, TNC’s, software, Internet connections and additionally updates to callsign databases. Expenses can add up very quickly.  Let your sysop know that you support him with occasional thanks or by kicking in some money into the cluster maintenance fund.