Looking for Skimmer "Reverse Beacons"
- PY1NB is developing a server to handle data from a worldwide network of
"reverse beacons" utilizing VE3NEA's CW Skimmer. Now that Alex has
released version 1.1, which incorporates a Telnet server, there is an
opportunity for users of CW Skimmer world-wide to help with this
potentially fascinating development.
For those who came late to the subject, a "reverse beacon" is a CW Skimmer
combined with a wide-band receiver (such as a SoftRock Lite) capable of
receiving a wide swath of a CW band. My experimental reverse beacon,
operating on 20 meters for the last several weeks, is a conceptual test of
the idea. It is currently chugging along, at a telnet address of
18.104.22.168 port 7300, sending out "spots" of everything it hears on the
band. Anyone with a telnet client, including virtually all the current
general and contest logging programs, can connect to it just like a DX
The purpose of the aggregator or "hub server" is to provide a single point
to which users of the future "reverse beacon" network can connect. Direct
connections to any individual CW Skimmer will probably quickly overload the
computer CPU, although I have had as many as 13 simultaneous telnet
connections with a relatively busy band to report on. It's not hard to
conceive of several hundred simultaneous users, hence the need for the server.
Even more important, the hub server will support a variety of queries. For
example, you will be able to transmit a CQ on any band, wait a few seconds,
and then ask the server, "Where am I being heard?" Similarly, you will be
able to ask the server, "What bands is Station X being heard on, and at
what locations." Spots will be archived in a database, so that you can ask
retrospective questions like "When did Station X begin operation on 20
meters yesterday." There will undoubtedly be many fascinating uses that
can be made of the data, either displaying it cartographically or in
response to complex queries like this.
But first, we need Skimmer owners to serve as "reverse beacons." If you
have CW Skimmer 1.1 working, are using a broadband receiver of any sort to
feed it with 48 KHz or more of any CW band, and you have an "always on"
connection to the Internet, then you can be part of this effort.
You don't have to commit to 24/7 availability of your CWSkimmer
station. Mine will be shut down when thunderstorms are in my area this
spring and summer, for example; the server is smart enough to resume
receiving spots from a "reverse beacon" when it returns to
action. Obviously, though, the more stations that are available at any
given time, the better the network will be.
If you'd like to get involved, drop me a note, and I'll help you get
started. You can download a full-featured 30-day trial copy of CW Skimmer
1.1 from www.dxatlas.com. Even if you initially downloaded the trial
version of 1.0, and your trial has ended, version 1.1 offers a new trial
The prototype hub server is located at http://skimmer.dxwatch.com It is
not receiving spots currently, pending the end of WPXSSB, but should be up
and running again soon after that. In the meantime, you can get the flavor
by contacting my CW Skimmer at 22.214.171.124 port 7300. Check the
instructions of your logging program or telnet client to learn how to
designate the port - typically, there are already DX clusters on the node
list of your software that are using explicitly designated ports, so you
can follow their example.
See you on the network?
73, Pete N4ZR