Aficionados of HF DXing will know that solar flux levels have been rather high over the last 3 months leading to exceptionally good propagation on 20 metres and the higher frequency HF bands. Just today, March 6, while configuring a new FT8 setup, I threw out a CQ on 15 metres at 5 Watts from the radio, going through a tuner and 250 feet of coax and finally reaching my extremely compromised 80 metre dipole and got two rather decent signal level responses from the US mid-West.

After that experience, I thought to visit the IARU web site because it does report from time to time on the solar activity trend - https://www.iaru-r1.org/2023/. Yes, there is a new article on the current solar state of affairs and it's really looking like Cycle 25 is going to beat all predictions. I've not reproduced the IARU charts here to respect copyright but you can check it just by going to the aforementioned URL. Suffice to say that the 10.7 cm. solar flux levels are averaging anywhere between 150 and 180 these days which certainly promises good propagation at 10 MHz. and higher.

Hang onto your HFDX hats folks, it looks like it may be a heck of a ride from now until 2026.

Of course, there is a down side to this and that is daytime propagation on frequencies below 10 MHz. which suffer from D Layer absorption. The low frequencies will likely close up after sunrise both locally and along the path to your intended DX destination but it may be that night time propagation will improve with higher ionisation in the F Layers.

73,

Hugo, VE3KTN

Appears in: Rambler Vol 65 Issue 7, March 2023