The NCDXF/IARU International HF Beacon Network The NCDXF/IARU International H.F. Beacon Network is a project jointly sponsored by the Northern California DX Foundation, NCDXF, and the International Amateur Radio Union, IARU. The network is made up of 18 high frequency beacons located in 18 countries across the world. Each beacon sequentially transmits in 5 amateur radio bands, 20 meters through 10 meters.

Table 1 lists the 18 beacons with frequencies and the minute and second within each hour of the start of the first transmission on each frequency for each beacon. Each transmission is repeated every 3 minutes. Note that currently China and Russia do not as yet have a beacon established and some beacons have transmission problems. This table is accessible on the world wide web with any updates by checking out http://www.ncdxf.org/beacon.htm

A beacon is made up of a Kenwood TS-50s transmitter linked to a custom NCDXF built control module synchronized by a Trimble Navigation Acutime (TM) GPS receiver. The signal is radiated using a Cushcraft R5 vertical antenna.

The purpose of the beacons is for determining the quality of HF propagation paths from your location to various parts of the world on each amateur radio band. The easiest way to do this is to listen to the beacon frequency on a band of interest for 3 minutes. During this time each beacon will sequentially transmit its callsign, in Morse code; followed by 4 one second dashes at a declining power level of 100, 10 , 1, and 0.1 watt. Each change represents a 10db or 2 S-unit drop in transmitted power. For more technical and operational information on the beacons, as well as software for automating a schedule, check the web site above or articles printed in QST magazine, Oct 1994, Nov 1994 and a follow-up report in Sept 1997 QST.

The following table gives the beacon locations within each country.

Beacon Locations

I recently listened to 21.150 Mhz. In the morning, I was able to hear the South Africa and Israel beacons indicating propagation to the middle east and South Atlantic. South America was also workable as Argentina, Peru and Venezuela popped up in sequential order. By late afternoon, propagation to the east of my location had disappeared, South America was still workable, and the beacons in the Western United States, Hawaii, and New Zealand made an appearance. I have yet to hear the Japanese beacon on 15 meters.

When propagation losses are low on a given path, a readable signal will be easily heard at the 100 milliwatt power level indicating excellent QRP operations are possible.

Next time you are thumbing your VFO knob up or down the bands, pause and listen for these beacons. It is fascinating to discover what propagation paths are open and waiting for someone to initiate a QSO, possibly one of the most memorable of your radio adventures.

73 and happy DXing
Greg VE3NXB
Email:ve3nxb@kwarc.org

Note:
Some of the information presented in this article has been obtained from the NCDXF web site and the pages of QST

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