Amateur Radio:  Usable HF Frequencies
(page refreshed every 20 minutes)

Use the indicated color (red, yellow, green, blue, white, etc.) to determine
the recommended HF frequencies for contacts.
Any white "bubble" indicates no suitable frequency or high absorption.


Click here to the University of Massachusetts' Lowell Center for Atmospheric Research and latest Ionograms. 

Additional propagation data, as well as geomagnetic and solar information:



HF chart provided by IPS.  Copyright  Commonwealth of Australia 2008.  Solar-Terrestrial and HF and VHF propagation data provided and Copyright of Paul L. Herrman.
This site is provided as a public service for amateur radio operators by Remarkable Technologies, Inc.