About DX Clusters
In the "good old days" DXers had to tune around to find their prey. Of course friends would help friends improve their DXCC score by getting together on 2 meter nets, or by telephoning each other to say "DX1DX is on frequency now".
But all this changed in 1986 when AK1A (Pavillion software) write the
original DX cluster program. This was a buggy DOS program that ran on a
node PC connected to a packet TNC. The AX25 packet protocol allowed many
connections on the same frequency - sharing time slots - to connect to the
node. Thus, one Dxer in Dallas could spot (report) DX1DX and all the other
stations connected to the node would receive the spot almost instantly.
The same thing would happen in Austin, Houston etc. Then the nodes would
use a 70cm link to talk to each other, and a huge network emerged.
Other web cluster sites have come along. I have found the cluster from Ham Radio Deluxe to be very fast. Here is the feed from it.
The next step is the telnet connection. This is based on the Telnet protocol which allows encrypted ASCII characters (plaintext) across a network. It allows a huge number of connections to be made in almost real time. This has the best of the original packet radio connection (spots are output as soon as they come in) and the web (world wide spots).
Now there are more versatile front-end programs for the Telnet DX
cluster connections. These allow thing like auto reconnects, audio alarms
& filtering of spots. Good examples are VE7CC's AR-User
program and HB9BZA's rxclus.
Thanks everybody for providing these sites.