The IARU sup­ports, with a small annu­al grant, a world­wide net­work of HF bea­cons known as the Inter­na­tion­al Bea­con Project (IBP). The bea­cons were con­struct­ed by vol­un­teers of the North­ern Cal­i­for­nia DX Foun­da­tion (NCDXF) and oper­ate from 18 loca­tions on the fol­low­ing fre­quen­cies on a time-shared basis: 14.100, 18.110, 21.150, 24.930, and 28.200 MHz. The NCDXF/IARU bea­cons help both ama­teur and non-ama­teur HF radio users assess the cur­rent con­di­tion of the ionosphere.

Addi­tion­al bea­cons oper­ate just above 28.200 MHz and nor­mal­ly are coor­di­nat­ed by region­al IARU Bea­con Coordinators.

Except for short-term exper­i­ments such as obser­va­tion of the effects of solar eclipses the IARU does not sup­port the oper­a­tion of ama­teur bea­cons below 14 MHz because of con­ges­tion in these bands.

For bea­cons above 30 MHz, please refer to the respec­tive region­al web­site under “On the Air.”