DX Cluster - EI7SDX



EI7SDX alias SHANDX is an Internet based packet cluster node managed from Shankill, South County Dublin, Ireland (IO63wf). However the cluster node is currently hosted on servers in London, UK. An experimental Amateur Radio Reporting System (APRS) DIGI, IGATE and Weather Station using the European APRS frequency of 144.800 MHz is also occasionally operational. EI7SDX-6 is the call-sign of the APRS server at Shankill; it gates APRS information from the 144.800 MHz radio port to the Internet and vice versa.

DX Cluster

Before July 2008 4 radio based ports were available on EI7SDX and EI7SDX-9 - 29.25 MHz, 70.325 MHz, 144.875 MHz and 433.675 MHz. These provided access to the DX cluster network, packet radio network and provided a limited APRS facility on the frequencies in use for other packet applications. EI7SDX has public access INET ports located at the address telnet://shandx.ath.cx:5000 and telnet://EI7SDX.ath.cx:7300. Until 2009 it was connected to the Internet by means of an Eircom ADSL connection. The node was and remains accessible using the telnet client in most PCs.

Prior to January 2003 two cluster nodes were in operation, a packet radio node EI3IO-3 and an Internet node EI3IO-4. During January 2003 the frequency of the 2 metre port was changed to 144.875 MHz and the two nodes were combined under the call EI3IO-4. In March 2003 the Irish regulator Comreg allocated the calls EI7SDX and EI7WDX to the Two Counties DX Cluster Group comprising EI7SDX in Shankill, Co. Dublin and EI7WDX in Bray, Co. Wicklow. EI7WDX has since closed down.

Radio ports were previously available on 29.25, 70.325, 144.875 and 433.675 MHz from Shankill, IO63WF and 70.325 and 144.950 MHz from Piperstown, IO63TF.

EI7SDX links with cluster nodes CX2SA-6, EI7WDX, F5MZN-3, K2UT and OZ5BBS-7.

From September 2008, due to lack of use, no radio access to EI7SDX has been provided. However an experimental APRS IGATE is occassionally operational on 144.800 MHz at Shankill.

EI7SDX originally utilised the DxNet cluster software developed by F5MZN. However in April 2003 the node was changed to G1TLH DXSpider software running with the WIN98SE OS and SV2AGW packet engine.

From August 2004 the EI7SDX (SHANDX) and EI7SDX-9 (renamed SDXIP) radio ports were controlled by XRouter running on a DOS PC. XRouter was developed by Paula Dowie, G8PZT.

Until 2009 EI7SDX cluster ran on a dedicated PC using the LINUX (Slackware) OS.

The Irish DX Cluster network currently comprises EI7SDX Shankill, Co Dublin and EI7MRE Castlebar, Co Mayo. You can read and download ‘Help’ information, manuals and the packet cluster ‘Command’ structure in the popular ‘Wiki’ format here.



Until 2009 there was also a NETROM node in the system provided by XRouter, EI7SDX-9 (SDXIP) It was TCP/IP enabled and had the IP address (ei7sdx.ampr.org). Around 100 NETROM nodes can normally be accessed around the world.


EI3IO Home page





(Telnet to DX Cluster)



(DX Cluster web-client)


DX Telnet Client


EI7SDX-9 NODE SDXIP (NETROM telnet access)


EI7SDX-9 SDXIP Web Pages

(Info and Stats, Port 3 is 144.8 MHz APRS)


Telnet Cluster Directory


Automatic Packet Reporting System (APRS) is an amateur radio based system for real time tactical digital communications. All such data is directed into the APRS Internet system (APRS-IS) and distributed globally for instant access. In addition to messages, alerts, announcements and bulletins, the most visible aspect of APRS is its map display. Anyone may place any object or information on their map and it is distributed to all maps of all users in the local RF network or monitoring the area via the internet. Any station, radio or object that has an attached GPS is automatically tracked. Other prominent map features are weather stations, alerts and objects and other map related amateur radio volunteer activities including Search and Rescue and signal direction finding.

EI7SDX-6 is the callsign of the APRS server DIGI and IGATE which operates occasionally in Shankill on 144.800 MHz. APRS information received on the 144.800 MHz radio port is passed to the Internet and vice versa. To find further information on APRS consult the APRS Wiki. To get started with APRS a popular windows based client program is UI-View. For more information on APRS in Ireland see EI7IG’s web pages.

APRS interface to the FINDU and APRS World Dadabases

The CALL field in the forms below requires a Call and SSID if appropriate e.g. EI7SDX-6. If you don't know the CALL/SSID wildcards can be used e.g. EI* or EI7S*. For example to list all EI calls providing APRS information, enter EI* in the Map Display box. To see the location of one of the listed stations on a map, enter the call in Map Display box. For example entering EI2SDR will provide the location of the South Dublin Radio Club.


Location(s) of call(s)

To find APRS stations near to a specific station:

 CALL:  during last within miles. With stations.