Propagation & DX
Solar cycles, grey line, duct openings — how signals travel and how to chase DX.
HF signals travel by bouncing between the ionosphere and the ground, so the sun decides which bands are open, when and to where. Solar flux, sunspots and geomagnetic activity shift the picture from day to day, while the time of day and the season decide which band is best at any given hour.
You do not need to be a physicist to use propagation. A few habits go a long way: check the solar indices before you operate, listen to beacons, know when greyline openings happen at your location, and learn how DX stations run a pileup so you can get through.
The guides below explain the basics and the tactics. For today's numbers, see our live band-conditions page, updated throughout the day.
Start here
- How HF Propagation Changes Through the Day: A Band-by-Band Guide
- How Solar Cycles Affect Radio Propagation: A Ham's Guide to the Sun
- Propagation Beacons and WWV: Free Tools for Checking Band Conditions
- Greyline Propagation: Working DX at Sunrise and Sunset
- HF DX: How to Make Worldwide Contacts on Ham Radio
- How to Work Split: DX Pileup Technique Every Ham Should Know