RDF (Radio Direction Finding) DX Challenge on HamSphere 4.0 starts 12th Sept
2015-09-08 17:40

RDF Challenge 12 Sept

HamSphere is pleased to announce the first RDF (Radio Direction Finding) DX Challenge on HamSphere 4.0 platform.

The RDF Challenge will be an 8 day event where several teams will participate and try to locate the physical position of various CW beacons operating from different locations around the world. The participating teams will attempt to find the best fix by homing into the beacons using HF DX Triangulation methods. The participating teams will work as a group with a team leader coordinating operations for each team. The bearings reported by members of the team will be collated, sanitized and analyzed be the team leader in consultation of members to finalize the prospective location of each beacon. The final report will be submitted to HamSphere at the end of the contest. Evaluation will be done by HamSphere and results will be subsequently declared.


There will be five CW beacons transmitting at any point in time during the contest. There will be one beacon on each of the following bands. 40m, 30m, 20m, 17m, and 15m. The beacons will be spread out across the world and across various continents. There locations will be unknown to all HamSphere users.


At the start of the contest on 12th September 2015, all five beacons will become operational. These beacons will transmit continuously (round the clock) for the first 48 Hours. Thereafter, at 00 UTC after 48 hours, all beacons will be randomly relocated to new geographic locations. The set of five beacons will be geographically relocated every 48 hours. Hence each team will have 48 hours to complete homing procedures for each set of beacons.

In other words, the 8 day RDF Challenge will give teams an opportunity to locate 5x4=20, a total of 20 beacons through the duration of the contest. The first set of beacons will operate from 00 UTC on 12th Sept to 00 UTC 14th Sept. Next set of beacons will be available from 00 UTC on 14th Sept to 00 UTC 16th Sept and so on.


Every beacon that is set up for the RDF Challenge will have an anonymous naming structure. The CW beacon identifier will not carry any clue to the location of the beacon. For instance, the first set of five beacons operating on the first two days will be called 40HS12, 30HS12, 20HS12, 17HS12 and 15HS12. The prefix specifies the band and the suffix specified the start date of the beacon. On 14th September when the beacons are switched and locations are changed they will be called 40HS14, 30HS14, 20HS14, 17HS14 and 15HS14 respectively. This will be the beacon identifier structure.

Every team should attempt to try and locate as many beacons as possible. As there will be four sets of five beacons spread over 8 days, teams will have an opportunity to locate a total of 20 beacons over the duration of the contest. However, please remember that any set of five beacons will be available only for two days before they are changed.


Beacons will be placed around the world with wide global geographic spread. They will be setup at random locations along the countryside and small obscure villages. None of the beacons will be located at any major city. This is to prevent speculation and to ensure that participants depend solely on the acquired readings during RDF. Each team will submit only one consolidated location for each beacon in Latitude and longitude format. The Lat/Lon format should be in decimal degrees (eg. 32.8361 N, 87.3174 E). After the closure of the contest HamSphere will evaluate the error distance of each reported beacon and assign score based on the following tentative formula - 10000/(error-distance[Km]). Total scores of all reported beacons by each team will be aggregated to arrive at the final score.

You will find more info in the RDF Facebook group: https://www.facebook.com/groups/672109146258046/