Reverse Beacon Networks (RBNs) are good tools for evaluating propagation conditions on a real-time basis. A conventional Beacon Network consists of a set of beacon stations around the world which transmit on known frequencies, times and power levels. A station can then listen to the beacon frequency and determine if the associated band is open to the places in the world where the beacons are located. A Reverse Beacon Network takes this one step further – each time a station that is a member of a RBN hears another station, it logs the station heard’s call sign, signal level received, mode of operation, and other data to a RBN website on the internet. The RBN website collects this data from stations all over the world and stores the data in a database for later display and analysis. An example of an RBN website is PSK Reporter. The picture above shows information from the PSK Reporter website illustrating a nice opening on the 20m band between Europe and the United States which occurred this afternoon. Each marker on the map shows a station which is participating in the RBN and the lines indicate a path over which one of the RBN stations heard another. The PSK Reporter example shown above is displaying information about stations which heard each other on all modes including digital, CW, SSB and others.
Programs like Ham Radio Deluxe/DM780, FLdigi, JT65HF, CW Skimmer, and others can act as RBN clients for PSK Reporter. You can use one of these clients along with the PSK Reporter website to do a real-time evaluation of your station’s performance and current band conditions. For example, the picture above shows the results of a 45 minute digital operating session from my station using our yagis pointed towards Europe. Using techniques like this, you can get a good idea of the real-time propagation conditions as well as how well your station is performing towards various parts of the world. If you use a digital mode program as the client for PSK Reporter, you should check your setup options to see how you can enable it to report stations that you hear to the PSK Reporter website.
Any station which is setup for digital mode operation already has everything needed to use RBNs. Your don’t need a lot of power for RBN operation. An omnidirectional antenna works best as it will transmit and hear equally well in all directions but most any antenna will allow you to evaluate your station’s performance and propagation conditions. If you have directional antennas such as yagi’s that you can point, you can still make worldwide measurements by operating for periods of 5 minutes in a given direction followed by rotating your antennas about 45 degrees. After about 45 minutes or so, you will have operated in all directions and the results for your call sign on the RBN website you are working with should give you a good picture of your signal coverage worldwide. Also note that fixed antennas like Dipoles, Inverted-Vs, etc. work just fine for RBN use as well. The results from the RBN website will tell you where you are being heard around the world. In the case of fixed antennas, the results will reflect a combination of the directional coverage of the antenna that you used for the measurements and the prevailing band conditions.
Another very useful RBN tool for evaluating propagation conditions and station performance in WSPR. WSPR uses the JT65 family of protocols in combination with the WSPRNet website to allow real-time measurements of band conditions and station performance using very low power levels (typically 1w or less). The picture above shows worldwide conditions on 20m from the WSPRnet website late in the afternoon.
There are a substantial number of WSPR enabled stations worldwide and any which hear a WSPR transmission from your station will report it to the WSPRnet website. As you can see from the picture above, the WSPR transmissions both sent from and heard by my WSPR station can be displayed on the WSPRnet website. This is an example of the actual performance of my station on 20m late this afternoon. You can let WSPR run at low power levels on an extended basis to enable continuous updates on the performance of your station and prevailing band conditions. If you decide to do this, it is important to properly monitor your station’s correct operation per your licensing authority’s control operator requirements.
WSPR uses a Client Application which controls your transceiver’s sending and receiving of WSPR beacon transmissions. The results are then reported to the WSPRnet website. Each transmission sequence by all WSPR stations in the world takes place on a narrow range of frequencies on each band and all stations are synchronized precisely to start and end their transmission and reception cycles on exact 2 minute intervals This synchronization along with other techniques implemented in the JT65 protocols used by WSPR allows signals sent at very low power levels (often less than 1w) to be received and decoded over long distances. In the picture above, each block of colored lines represents the WSPR transmissions heard by my station on the 20m band during a 2 minute cycle. As you can see, there was quite a bit of activity in the WSPR segment of the 20m band at the time I made the measurements. You can find the latest WSPR client software along with information on how to setup and configure the program for your transceiver on the WSJT website.
I encourage our readers to give PSK Reporter and WSPR a try. They are a very useful tool and its fun to see how your station is performing in real-time.
– Fred (AB1OC)