Long winter nights are bad news for the garden and good news for the low bands. From November through February, 160, 80 and 40 metres come alive, and the hours around sunrise and sunset can deliver DX you’ll never hear in summer.
The grey line is the band of twilight that circles the earth between day and night. Along that line, the D layer, which soaks up low-frequency signals in daylight, is fading or hasn’t formed yet, while the higher layers are still doing their job. Signals that travel along the grey line can go a very long way on surprisingly little power.
Why winter is better
- Long nights mean more hours when 160, 80 and 40 m are open.
- Less lightning means far less static crash on the low bands.
- From southern Alberta, the grey line in winter often lines up with Europe at our sunrise and with Asia and the Pacific at our sunset.
How to use it
- Be on the air in the 30 minutes either side of your local sunrise and sunset.
- Open PropMap and look at the live grey-line map. Any station sitting on the same twilight band as you is worth calling.
- Listen first. Grey-line openings can be short, and the band can go from empty to busy in minutes.
- 40 m is the easy place to start. 80 and 160 m reward a bigger antenna and a quieter location.
Check the live grey line and band outlook on PropMap before your next sunrise session.
Related: PropMap: live propagation · HF Overview